RP2040: Fix use of deprecated volatile semantics for C++20 (#1318) (#1319)

Co-authored-by: Mathias Gredal <matg@universal-robots.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>

.github/.cSpellWords.txt

@@ -23,6 +23,7 @@ AIRCR
 ALMIEN
 ALMV
 ANDC
+andi
 ANDCCR
 APIC
 APROCFREQ
@@ -47,6 +48,7 @@ bcpc
 BCPC
 beevt
 BEEVT
+beqz
 BERR
 bfextu
 Biagioni
@@ -298,6 +300,7 @@ FADD
 FCMD
 fcolor
 FCSE
+fcsr
 fdiagnostics
 fdiv
 FDIV
@@ -783,6 +786,7 @@ SHPR
 SHTIM
 SIFIVE
 sinclude
+slli
 SODR
 SOFTIRQ
 SPCK
@@ -934,6 +938,7 @@ USRIO
 utest
 utilises
 utilising
+vcsr
 VDDCORE
 vect
 Vect
@@ -944,6 +949,7 @@ visualisation
 vldmdbeq
 vldmia
 vldmiaeq
+vlenb
 VMSRNE
 vpop
 VPOPNE
@@ -951,6 +957,7 @@ vpush
 VPUSHNE
 VRPM
 Vrtc
+vsetvl
 vstmdbeq
 vstmiaeq
 VTOR

.github/scripts/kernel_checker.py

@@ -114,6 +114,10 @@ KERNEL_ARM_COLLAB_FILES_PATTERNS = [
     r'.*portable/.*/ARM_CM35*',
     r'.*portable/.*/ARM_CM55*',
     r'.*portable/.*/ARM_CM85*',
+    r'.*portable/.*/ARM_CM0*',
+    r'.*portable/.*/ARM_CM3_MPU*',
+    r'.*portable/.*/ARM_CM4_MPU*',
+    r'.*portable/.*/ARM_CM4F_MPU*',
 ]
 
 KERNEL_HEADER = [
@@ -150,8 +154,8 @@ KERNEL_HEADER = [
 FREERTOS_COPYRIGHT_REGEX = r"^(;|#)?( *(\/\*|\*|#|\/\/))? Copyright \(C\) 20\d\d Amazon.com, Inc. or its affiliates. All Rights Reserved\.( \*\/)?$"
 
 FREERTOS_ARM_COLLAB_COPYRIGHT_REGEX = r"(^(;|#)?( *(\/\*|\*|#|\/\/))? Copyright \(C\) 20\d\d Amazon.com, Inc. or its affiliates. All Rights Reserved\.( \*\/)?$)|" + \
-                                      r"(^(;|#)?( *(\/\*|\*|#|\/\/))? Copyright 20\d\d Arm Limited and/or its affiliates( \*\/)?$)|" + \
+                                      r"(^(;|#)?( *(\/\*|\*|#|\/\/))? Copyright 20\d\d(-20\d\d)? Arm Limited and/or its affiliates( +<open-source-office@arm\.com>)?( \*\/)?$)|" + \
-                                      r"(^(;|#)?( *(\/\*|\*|#|\/\/))? <open-source-office@arm.com>( \*\/)?$)"
+                                      r"(^(;|#)?( *(\/\*|\*|#|\/\/))? <open-source-office@arm\.com>( \*\/)?$)"
 
 
 class KernelHeaderChecker(HeaderChecker):

.github/workflows/auto-release.yml

@@ -18,6 +18,8 @@ on:
 
 jobs:
   release-packager:
+    permissions:
+      id-token: write
     name: Release Packager
     runs-on: ubuntu-latest
     steps:
@@ -117,6 +119,14 @@ jobs:
           ./tools/.github/scripts/release.py "$REPO_OWNER" --kernel-repo-path=local_kernel --kernel-commit="$COMMIT_SHA_2" --new-kernel-version="$VERSION_NUMBER" --new-kernel-main-br-version="$MAIN_BR_VERSION_NUMBER"
           exit $?
 
+      - name: Backup Release Asset
+        uses: FreeRTOS/CI-CD-Github-Actions/artifact-backup@main
+        with:
+          # This is dependent on the release script putting this zip file
+          # in this exact location.
+          artifact_path: ./FreeRTOS-KernelV${{ github.event.inputs.version_number }}.zip
+          release_tag: ${{ github.event.inputs.version_number }}
+
       - name: Cleanup
         env:
           VERSION_NUMBER: ${{ github.event.inputs.version_number }}

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ on:
   workflow_dispatch:
 jobs:
   formatting:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4.1.1
       - name: Check Formatting of FreeRTOS-Kernel Files

.github/workflows/coverity_scan.yml

@@ -42,11 +42,22 @@ jobs:
           # ${{ env.stepName }}
           echo -e "::group::${{ env.bashInfo }} ${{ env.stepName }} ${{ env.bashEnd }}"
 
-          wget -nv -qO- https://scan.coverity.com/download/linux64 --post-data "token=${COVERITY_TOKEN}&project=FreeRTOS-Kernel" | tar -zx --one-top-level=cov_scan --strip-components 1
+          wget -nv -q -O "$HOME/cov-analysis.tar.gz" https://scan.coverity.com/download/linux64 --post-data="token=${COVERITY_TOKEN}&project=FreeRTOS-Kernel"
-          echo "cov_scan_path=$(pwd)/cov_scan/bin" >> $GITHUB_ENV
           
+          EXPECTED_MD5="e4418004b073140d67390cffba79c3b2"
+          GENERATED_MD5=$(md5sum "$HOME/cov-analysis.tar.gz" | awk '{print $1}')
+
+          if [ "$GENERATED_MD5" = "$EXPECTED_MD5" ]; then
+            tar -zxf "$HOME/cov-analysis.tar.gz" --one-top-level=cov_scan -C "$HOME"            
+            echo "cov_scan_path=$HOME/cov_scan/bin" >> $GITHUB_ENV
+            sudo rm -f "$HOME/cov-analysis.tar.gz"
             echo "::endgroup::"
             echo -e "${{ env.bashPass }} ${{ env.stepName }} ${{ env.bashEnd }} "
+          else
+            echo -e "${{ env.bashFail }} MD5 checksum verification failed for cov-analysis.tar.gz ${{ env.bashEnd }}"
+            echo -e "${{ env.bashFail }} ${{ env.stepName }} ${{ env.bashEnd }}"
+            exit -1            
+          fi
 
       - env:
           stepName: Coverity Build

.github/workflows/formatting.yml

@@ -1,25 +0,0 @@
-name: Format Pull Request Files
-
-on:
-  issue_comment:
-    types: [created]
-
-env:
-  bashPass: \033[32;1mPASSED -
-  bashInfo: \033[33;1mINFO -
-  bashFail: \033[31;1mFAILED -
-  bashEnd:  \033[0m
-
-jobs:
-  Formatting:
-    name: Run Formatting Check
-    if: ${{ github.event.issue.pull_request &&
-        ( ( github.event.comment.body == '/bot run uncrustify' ) ||
-          ( github.event.comment.body == '/bot run formatting' ) ) }}
-    runs-on: ubuntu-20.04
-    steps:
-    - name: Apply Formatting Fix
-      id: check-formatting
-      uses: FreeRTOS/CI-CD-Github-Actions/formatting-bot@main
-      with:
-        exclude-dirs: portable

.github/workflows/kernel-checks.yml

@@ -5,7 +5,7 @@ on: [push, pull_request]
 jobs:
   kernel-checker:
     name: FreeRTOS Kernel Header Checks
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       # Install python 3
       - name: Tool Setup

.github/workflows/kernel-demos.yml

@@ -156,14 +156,27 @@ jobs:
         run: |
           # ${{ env.stepName }}
           echo -e "::group::${{ env.bashInfo }} ${{ env.stepName }} ${{ env.bashEnd }}"
-          curl -L -O https://dr-download.ti.com/software-development/ide-configuration-compiler-or-debugger/MD-LlCjWuAbzH/9.3.1.2/msp430-gcc-full-linux-x64-installer-9.3.1.2.7z
           sudo apt update -y
           sudo apt install -y p7zip-full
+          pushd $HOME
+          curl -L -o msp430-gcc-full-linux-x64-installer-9.3.1.2.7z https://dr-download.ti.com/software-development/ide-configuration-compiler-or-debugger/MD-LlCjWuAbzH/9.3.1.2/msp430-gcc-full-linux-x64-installer-9.3.1.2.7z
+          
+          EXPECTED_MD5="2db2f99b4cd5c541ca0389ee20c67527"
+          GENERATED_MD5=$(md5sum msp430-gcc-full-linux-x64-installer-9.3.1.2.7z | awk '{print $1}')
+
+          if [ "$GENERATED_MD5" = "$EXPECTED_MD5" ]; then          
             7z x ./msp430-gcc-full-linux-x64-installer-9.3.1.2.7z
             chmod +x ./msp430-gcc-full-linux-x64-installer-9.3.1.2.run
             sudo ./msp430-gcc-full-linux-x64-installer-9.3.1.2.run --prefix /usr/bin/msp430-gcc --mode unattended
             echo "::endgroup::"
+            popd
             echo -e "${{ env.bashPass }} ${{ env.stepName }} ${{ env.bashEnd }}"
+          else
+            popd
+            echo -e "${{ env.bashFail }} MD5 checksum verification failed for msp430-gcc-full-linux-x64-installer-9.3.1.2.7z ${{ env.bashEnd }}"
+            echo -e "${{ env.bashFail }} ${{ env.stepName }} ${{ env.bashEnd }}"
+            exit -1
+          fi
 
       - name: Build msp430_GCC Demo
         shell: bash
@@ -211,21 +224,23 @@ jobs:
           sudo apt install -y autogen gawk libgmp-dev libmpc-dev libmpfr-dev
           sudo apt install -y patchutils sharutils zlib1g-dev autoconf2.64
 
+          pushd $HOME
           # Download the mb-gcc toolchain from github
-          curl -L -O https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/binutils-microblaze_2.35-2021-0623+1_amd64.deb;
+          curl -L -o binutils-microblaze.deb https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/binutils-microblaze_2.35-2021-0623+1_amd64.deb;
-          curl -L -O https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/gcc-microblaze_10.2.0-2021-0623+2_amd64.deb;
+          curl -L -o gcc-microblaze.deb https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/gcc-microblaze_10.2.0-2021-0623+2_amd64.deb;
-          curl -L -O https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/libnewlib-microblaze-dev_3.3.0-2021-0623+3_all.deb;
+          curl -L -o libnewlib-microblaze-dev.deb https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/libnewlib-microblaze-dev_3.3.0-2021-0623+3_all.deb;
-          curl -L -O https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/libnewlib-microblaze-doc_3.3.0-2021-0623+3_all.deb;
+          curl -L -o libnewlib-microblaze-doc.deb https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/libnewlib-microblaze-doc_3.3.0-2021-0623+3_all.deb;
-          curl -L -O https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/libnewlib-microblaze_3.3.0-2021-0623+3_all.deb;
+          curl -L -o libnewlib-microblaze.deb https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/libnewlib-microblaze_3.3.0-2021-0623+3_all.deb;
-          curl -L -O https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/newlib-source_3.3.0-2021-0623+3_all.deb;
+          curl -L -o newlib-source.deb https://github.com/mdednev/mb-gcc/releases/download/2021-0623%2B2/newlib-source_3.3.0-2021-0623+3_all.deb;
+          popd
 
           # Install the packages for the toolchain
-          sudo apt install -y ./binutils-microblaze*.deb;
+          sudo apt install -y $HOME/binutils-microblaze.deb;
-          sudo apt install -y ./gcc-microblaze*.deb;
+          sudo apt install -y $HOME/gcc-microblaze.deb;
-          sudo apt install -y ./libnewlib-microblaze-dev*.deb;
+          sudo apt install -y $HOME/libnewlib-microblaze-dev.deb;
-          sudo apt install -y ./libnewlib-microblaze-doc*.deb;
+          sudo apt install -y $HOME/libnewlib-microblaze-doc.deb;
-          sudo apt install -y ./libnewlib-microblaze*.deb;
+          sudo apt install -y $HOME/libnewlib-microblaze.deb;
-          sudo apt install -y ./newlib-source*.deb;
+          sudo apt install -y $HOME/newlib-source.deb;
 
           # Validate that the toolchain is in the path and can be called
           which mb-gcc

.github/workflows/unit-tests.yml

@@ -3,7 +3,7 @@ on: [push, pull_request]
 
 jobs:
   run:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - name: Checkout Parent Repository
       uses: actions/checkout@v4.1.1

README.md

@@ -1,5 +1,5 @@
 [![CMock Unit Tests](https://github.com/FreeRTOS/FreeRTOS-Kernel/actions/workflows/unit-tests.yml/badge.svg?branch=main&event=push)](https://github.com/FreeRTOS/FreeRTOS-Kernel/actions/workflows/unit-tests.yml?query=branch%3Amain+event%3Apush+workflow%3A%22CMock+Unit+Tests%22++)
-[![codecov](https://codecov.io/gh/FreeRTOS/FreeRTOS-Kernel/badge.svg?branch=main)](https://codecov.io/gh/FreeRTOS/FreeRTOS-Kernel)
+[![codecov](https://app.codecov.io/gh/FreeRTOS/FreeRTOS-Kernel/badge.svg?branch=main)](https://codecov.io/gh/FreeRTOS/FreeRTOS-Kernel)
 
 ## Getting started
 

event_groups.c

@@ -501,7 +501,7 @@
     }
 /*-----------------------------------------------------------*/
 
-    #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
+    #if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
 
         BaseType_t xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup,
                                                 const EventBits_t uxBitsToClear )
@@ -518,7 +518,7 @@
             return xReturn;
         }
 
-    #endif /* if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
+    #endif /* if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
 /*-----------------------------------------------------------*/
 
     EventBits_t xEventGroupGetBitsFromISR( EventGroupHandle_t xEventGroup )
@@ -812,7 +812,7 @@
     }
 /*-----------------------------------------------------------*/
 
-    #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
+    #if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
 
         BaseType_t xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup,
                                               const EventBits_t uxBitsToSet,
@@ -830,7 +830,7 @@
             return xReturn;
         }
 
-    #endif /* if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
+    #endif /* if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
 /*-----------------------------------------------------------*/
 
     #if ( configUSE_TRACE_FACILITY == 1 )

examples/template_configuration/FreeRTOSConfig.h

@@ -415,6 +415,8 @@
  * number of the failing assert (for example, "vAssertCalled( __FILE__, __LINE__
  * )" or it can simple disable interrupts and sit in a loop to halt all
  * execution on the failing line for viewing in a debugger. */
+
+/* *INDENT-OFF* */
 #define configASSERT( x )         \
     if( ( x ) == 0 )              \
     {                             \
@@ -422,6 +424,7 @@
         for( ; ; )                \
         ;                         \
     }
+/* *INDENT-ON* */
 
 /******************************************************************************/
 /* FreeRTOS MPU specific definitions. *****************************************/

include/FreeRTOS.h

@@ -101,6 +101,16 @@
     #define configASSERT_DEFINED    1
 #endif
 
+/* Set configENABLE_PAC and/or configENABLE_BTI to 1 to enable PAC and/or BTI
+ * support and 0 to disable them. These are currently used in ARMv8.1-M ports. */
+#ifndef configENABLE_PAC
+    #define configENABLE_PAC    0
+#endif
+
+#ifndef configENABLE_BTI
+    #define configENABLE_BTI    0
+#endif
+
 /* Basic FreeRTOS definitions. */
 #include "projdefs.h"
 
@@ -3040,16 +3050,6 @@
     #define configCONTROL_INFINITE_LOOP()
 #endif
 
-/* Set configENABLE_PAC and/or configENABLE_BTI to 1 to enable PAC and/or BTI
- * support and 0 to disable them. These are currently used in ARMv8.1-M ports. */
-#ifndef configENABLE_PAC
-    #define configENABLE_PAC    0
-#endif
-
-#ifndef configENABLE_BTI
-    #define configENABLE_BTI    0
-#endif
-
 /* Sometimes the FreeRTOSConfig.h settings only allow a task to be created using
  * dynamically allocated RAM, in which case when any task is deleted it is known
  * that both the task's stack and TCB need to be freed.  Sometimes the

include/croutine.h

@@ -246,7 +246,10 @@ void vCoRoutineSchedule( void );
  * \defgroup crSTART crSTART
  * \ingroup Tasks
  */
+
+/* *INDENT-OFF* */
 #define crEND()    }
+/* *INDENT-ON* */
 
 /*
  * These macros are intended for internal use by the co-routine implementation

include/event_groups.h

@@ -452,13 +452,10 @@ EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup,
  * \defgroup xEventGroupClearBitsFromISR xEventGroupClearBitsFromISR
  * \ingroup EventGroup
  */
-#if ( configUSE_TRACE_FACILITY == 1 )
+#if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
     BaseType_t xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup,
                                             const EventBits_t uxBitsToClear ) PRIVILEGED_FUNCTION;
-#else
+#endif /* if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
-    #define xEventGroupClearBitsFromISR( xEventGroup, uxBitsToClear ) \
-    xTimerPendFunctionCallFromISR( vEventGroupClearBitsCallback, ( void * ) ( xEventGroup ), ( uint32_t ) ( uxBitsToClear ), NULL )
-#endif
 
 /**
  * event_groups.h
@@ -607,14 +604,11 @@ EventBits_t xEventGroupSetBits( EventGroupHandle_t xEventGroup,
  * \defgroup xEventGroupSetBitsFromISR xEventGroupSetBitsFromISR
  * \ingroup EventGroup
  */
-#if ( configUSE_TRACE_FACILITY == 1 )
+#if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
     BaseType_t xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup,
                                           const EventBits_t uxBitsToSet,
                                           BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
-#else
+#endif /* if ( ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
-    #define xEventGroupSetBitsFromISR( xEventGroup, uxBitsToSet, pxHigherPriorityTaskWoken ) \
-    xTimerPendFunctionCallFromISR( vEventGroupSetBitsCallback, ( void * ) ( xEventGroup ), ( uint32_t ) ( uxBitsToSet ), ( pxHigherPriorityTaskWoken ) )
-#endif
 
 /**
  * event_groups.h

include/list.h

@@ -44,7 +44,7 @@
  *
  * In addition to it's value, each list item contains a pointer to the next
  * item in the list (pxNext), a pointer to the list it is in (pxContainer)
- * and a pointer to back to the object that contains it.  These later two
+ * and a pointer back to the object that contains it.  These later two
  * pointers are included for efficiency of list manipulation.  There is
  * effectively a two way link between the object containing the list item and
  * the list item itself.

include/mpu_prototypes.h

@@ -409,13 +409,16 @@ EventBits_t MPU_xEventGroupSync( EventGroupHandle_t xEventGroup,
 
 BaseType_t MPU_xEventGroupGetStaticBuffer( EventGroupHandle_t xEventGroup,
                                            StaticEventGroup_t ** ppxEventGroupBuffer ) PRIVILEGED_FUNCTION;
-BaseType_t MPU_xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup,
-                                            const EventBits_t uxBitsToClear ) PRIVILEGED_FUNCTION;
-BaseType_t MPU_xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup,
-                                          const EventBits_t uxBitsToSet,
-                                          BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
 EventBits_t MPU_xEventGroupGetBitsFromISR( EventGroupHandle_t xEventGroup ) PRIVILEGED_FUNCTION;
 
+#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
+    BaseType_t MPU_xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup,
+                                                const EventBits_t uxBitsToClear ) FREERTOS_SYSTEM_CALL;
+    BaseType_t MPU_xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup,
+                                              const EventBits_t uxBitsToSet,
+                                              BaseType_t * pxHigherPriorityTaskWoken ) FREERTOS_SYSTEM_CALL;
+#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
+
 /* MPU versions of message/stream_buffer.h API functions. */
 size_t MPU_xStreamBufferSend( StreamBufferHandle_t xStreamBuffer,
                               const void * pvTxData,

include/semphr.h

@@ -37,8 +37,8 @@
 
 typedef QueueHandle_t SemaphoreHandle_t;
 
-#define semBINARY_SEMAPHORE_QUEUE_LENGTH    ( ( uint8_t ) 1U )
+#define semBINARY_SEMAPHORE_QUEUE_LENGTH    ( ( UBaseType_t ) 1U )
-#define semSEMAPHORE_QUEUE_ITEM_LENGTH      ( ( uint8_t ) 0U )
+#define semSEMAPHORE_QUEUE_ITEM_LENGTH      ( ( UBaseType_t ) 0U )
 #define semGIVE_BLOCK_TIME                  ( ( TickType_t ) 0U )
 
 

portable/ARMv8M/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/CMakeLists.txt

@@ -769,6 +769,7 @@ add_library(freertos_kernel_port OBJECT
 if( FREERTOS_PORT MATCHES "GCC_ARM_CM(3|4)_MPU" OR
     FREERTOS_PORT STREQUAL "IAR_ARM_CM4F_MPU" OR
     FREERTOS_PORT STREQUAL "RVDS_ARM_CM4_MPU" OR
+    FREERTOS_PORT STREQUAL "GCC_ARM_CRX_MPU" OR
     FREERTOS_PORT MATCHES "GCC_ARM_CM(23|33|55|85)_NTZ_NONSECURE" OR
     FREERTOS_PORT MATCHES "GCC_ARM_CM(23|33|55|85)_NONSECURE" OR
     FREERTOS_PORT MATCHES "GCC_ARM_CM(33|55|85)_TFM" OR

portable/Common/mpu_wrappers_v2.c

@@ -1059,8 +1059,8 @@
                                                   configRUN_TIME_COUNTER_TYPE * pulTotalRunTime ) /* PRIVILEGED_FUNCTION */
         {
             UBaseType_t uxReturn = 0;
-            UBaseType_t xIsTaskStatusArrayWriteable = pdFALSE;
+            BaseType_t xIsTaskStatusArrayWriteable = pdFALSE;
-            UBaseType_t xIsTotalRunTimeWriteable = pdFALSE;
+            BaseType_t xIsTotalRunTimeWriteable = pdFALSE;
             uint32_t ulArraySize = ( uint32_t ) uxArraySize;
             uint32_t ulTaskStatusSize = ( uint32_t ) sizeof( TaskStatus_t );
 
@@ -4282,7 +4282,7 @@
     #endif /* #if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configUSE_EVENT_GROUPS == 1 ) ) */
 /*-----------------------------------------------------------*/
 
-    #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
+    #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
 
         BaseType_t MPU_xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup,
                                                     const EventBits_t uxBitsToClear ) /* PRIVILEGED_FUNCTION */
@@ -4306,10 +4306,10 @@
             return xReturn;
         }
 
-    #endif /* #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
+    #endif /* #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
 /*-----------------------------------------------------------*/
 
-    #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
+    #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) )
 
         BaseType_t MPU_xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup,
                                                   const EventBits_t uxBitsToSet,
@@ -4334,7 +4334,7 @@
             return xReturn;
         }
 
-    #endif /* #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
+    #endif /* #if ( ( configUSE_EVENT_GROUPS == 1 ) && ( INCLUDE_xTimerPendFunctionCall == 1 ) && ( configUSE_TIMERS == 1 ) ) */
 /*-----------------------------------------------------------*/
 
     #if ( configUSE_EVENT_GROUPS == 1 )

portable/GCC/ARM_CM0/port.c

@@ -1,6 +1,8 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * Copyright 2025 Arm Limited and/or its affiliates
+ * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
  *
@@ -915,7 +917,10 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
         uint32_t ulSystemCallLocation, i;
-        const uint32_t ulStackFrameSize = 8;
+        /* Hardware Saved Stack Frame Size upon Exception entry:
+         * Basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+         */
+        const uint32_t ulHardwareSavedExceptionFrameSize = 8;
 
         #if defined( __ARMCC_VERSION )
 
@@ -955,10 +960,10 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -981,7 +986,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1036,7 +1041,10 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
         uint32_t ulSystemCallLocation, i;
-        const uint32_t ulStackFrameSize = 8;
+        /* Hardware Saved Stack Frame Size upon Exception entry:
+         * Basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+         */
+        const uint32_t ulHardwareSavedExceptionFrameSize = 8;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1072,10 +1080,10 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM23/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM23_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM33/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM33_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM35P/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM35P_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM3_MPU/port.c

@@ -1,6 +1,8 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * Copyright 2025 Arm Limited and/or its affiliates
+ * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
  *
@@ -484,7 +486,10 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
         uint32_t ulSystemCallLocation, i;
-        const uint32_t ulStackFrameSize = 8;
+        /* Hardware Saved Stack Frame Size upon Exception entry:
+         * Basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+         */
+        const uint32_t ulHardwareSavedExceptionFrameSize = 8;
 
         #if defined( __ARMCC_VERSION )
             /* Declaration when these variable are defined in code instead of being
@@ -520,10 +525,10 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -541,7 +546,7 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Store the value of the Link Register before the SVC was raised.
              * It contains the address of the caller of the System Call entry
@@ -594,7 +599,10 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
         uint32_t ulSystemCallLocation, i;
-        const uint32_t ulStackFrameSize = 8;
+        /* Hardware Saved Stack Frame Size upon Exception entry:
+         * Basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+         */
+        const uint32_t ulHardwareSavedExceptionFrameSize = 8;
 
         #if defined( __ARMCC_VERSION )
             /* Declaration when these variable are defined in code instead of being
@@ -626,10 +634,10 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM4_MPU/port.c

@@ -1,6 +1,8 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * Copyright 2025 Arm Limited and/or its affiliates
+ * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
  *
@@ -518,7 +520,7 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
             /* Declaration when these variable are defined in code instead of being
@@ -553,10 +555,14 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
             {
                 /* Extended frame i.e. FPU in use. */
-                ulStackFrameSize = 26;
+                ulHardwareSavedExceptionFrameSize = 26;
                 __asm volatile (
                     " vpush {s0}         \n" /* Trigger lazy stacking. */
                     " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -566,14 +572,14 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
             else
             {
                 /* Standard frame i.e. FPU not in use. */
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -591,7 +597,7 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Store the value of the Link Register before the SVC was raised.
              * It contains the address of the caller of the System Call entry
@@ -644,7 +650,7 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
             /* Declaration when these variable are defined in code instead of being
@@ -675,10 +681,14 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
             {
                 /* Extended frame i.e. FPU in use. */
-                ulStackFrameSize = 26;
+                ulHardwareSavedExceptionFrameSize = 26;
                 __asm volatile (
                     " vpush {s0}         \n" /* Trigger lazy stacking. */
                     " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -688,14 +698,14 @@ void vSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
             else
             {
                 /* Standard frame i.e. FPU not in use. */
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM55/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM55_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM85/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CM85_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/GCC/ARM_CRx_MPU/mpu_wrappers_v2_asm.S

@@ -30,7 +30,7 @@
 
     .arm
     .syntax unified
-    .section freertos_system_calls
+    .section freertos_system_calls, "ax"
 
 #define FREERTOS_ASSEMBLY
     #include "FreeRTOSConfig.h"

portable/GCC/ARM_CRx_MPU/portASM.S

@@ -28,7 +28,7 @@
 
     .arm
     .syntax unified
-    .section privileged_functions
+    .section privileged_functions, "ax"
 
 #define FREERTOS_ASSEMBLY
     #include "portmacro_asm.h"

portable/GCC/RISC-V/chip_specific_extensions/Pulpino_Vega_RV32M1RM/freertos_risc_v_chip_specific_extensions.h

@@ -80,22 +80,22 @@ csrr t2, lpcount0
 csrr t3, lpstart1
 csrr t4, lpend1
 csrr t5, lpcount1
-sw t0, 1 * portWORD_SIZE( sp )
+sw t0, 2 * portWORD_SIZE( sp )
-sw t1, 2 * portWORD_SIZE( sp )
+sw t1, 3 * portWORD_SIZE( sp )
-sw t2, 3 * portWORD_SIZE( sp )
+sw t2, 4 * portWORD_SIZE( sp )
-sw t3, 4 * portWORD_SIZE( sp )
+sw t3, 5 * portWORD_SIZE( sp )
-sw t4, 5 * portWORD_SIZE( sp )
+sw t4, 6 * portWORD_SIZE( sp )
-sw t5, 6 * portWORD_SIZE( sp )
+sw t5, 7 * portWORD_SIZE( sp )
    .endm
 
 /* Restore the additional registers found on the Pulpino. */
    .macro portasmRESTORE_ADDITIONAL_REGISTERS
-lw t0, 1 * portWORD_SIZE( sp ) /* Load additional registers into accessible temporary registers. */
+lw t0, 2 * portWORD_SIZE( sp ) /* Load additional registers into accessible temporary registers. */
-lw t1, 2 * portWORD_SIZE( sp )
+lw t1, 3 * portWORD_SIZE( sp )
-lw t2, 3 * portWORD_SIZE( sp )
+lw t2, 4 * portWORD_SIZE( sp )
-lw t3, 4 * portWORD_SIZE( sp )
+lw t3, 5 * portWORD_SIZE( sp )
-lw t4, 5 * portWORD_SIZE( sp )
+lw t4, 6 * portWORD_SIZE( sp )
-lw t5, 6 * portWORD_SIZE( sp )
+lw t5, 7 * portWORD_SIZE( sp )
 csrw lpstart0, t0
 csrw lpend0, t1
 csrw lpcount0, t2

portable/GCC/RISC-V/port.c

@@ -90,7 +90,7 @@ void vPortSetupTimerInterrupt( void ) __attribute__( ( weak ) );
 uint64_t ullNextTime = 0ULL;
 const uint64_t * pullNextTime = &ullNextTime;
 const size_t uxTimerIncrementsForOneTick = ( size_t ) ( ( configCPU_CLOCK_HZ ) / ( configTICK_RATE_HZ ) ); /* Assumes increment won't go over 32-bits. */
-uint64_t const ullMachineTimerCompareRegisterBase = configMTIMECMP_BASE_ADDRESS;
+UBaseType_t const ullMachineTimerCompareRegisterBase = configMTIMECMP_BASE_ADDRESS;
 volatile uint64_t * pullMachineTimerCompareRegister = NULL;
 
 /* Holds the critical nesting value - deliberately non-zero at start up to

portable/GCC/RISC-V/portASM.S

@@ -162,7 +162,6 @@ definitions. */
  * where the global and thread pointers are currently assumed to be constant so
  * are not saved:
  *
- * mstatus
  * xCriticalNesting
  * x31
  * x30
@@ -192,18 +191,13 @@ definitions. */
  * x6
  * x5
  * portTASK_RETURN_ADDRESS
+ * [FPU registers (when enabled/available) go here]
+ * [VPU registers (when enabled/available) go here]
  * [chip specific registers go here]
+ * mstatus
  * pxCode
  */
 pxPortInitialiseStack:
-    csrr t0, mstatus                    /* Obtain current mstatus value. */
-    andi t0, t0, ~0x8                   /* Ensure interrupts are disabled when the stack is restored within an ISR.  Required when a task is created after the schedulre has been started, otherwise interrupts would be disabled anyway. */
-    addi t1, x0, 0x188                  /* Generate the value 0x1880, which are the MPIE and MPP bits to set in mstatus. */
-    slli t1, t1, 4
-    or t0, t0, t1                       /* Set MPIE and MPP bits in mstatus value. */
-
-    addi a0, a0, -portWORD_SIZE
-    store_x t0, 0(a0)                   /* mstatus onto the stack. */
     addi a0, a0, -portWORD_SIZE         /* Space for critical nesting count. */
     store_x x0, 0(a0)                   /* Critical nesting count starts at 0 for every task. */
 
@@ -212,10 +206,12 @@ pxPortInitialiseStack:
 #else
     addi a0, a0, -(22 * portWORD_SIZE)  /* Space for registers x10-x31. */
 #endif
-    store_x a2, 0(a0)                   /* Task parameters (pvParameters parameter) goes into register X10/a0 on the stack. */
+    store_x a2, 0(a0)                   /* Task parameters (pvParameters parameter) goes into register x10/a0 on the stack. */
-    addi a0, a0, -(6 * portWORD_SIZE)   /* Space for registers x5-x9 + taskReturnAddress. */
+
+    addi a0, a0, -(6 * portWORD_SIZE)   /* Space for registers x5-x9 + taskReturnAddress (register x1). */
     load_x t0, xTaskReturnAddress
     store_x t0, 0(a0)                   /* Return address onto the stack. */
+
     addi t0, x0, portasmADDITIONAL_CONTEXT_SIZE /* The number of chip specific additional registers. */
 chip_specific_stack_frame:              /* First add any chip specific registers to the stack frame being created. */
     beq t0, x0, 1f                      /* No more chip specific registers to save. */
@@ -224,6 +220,31 @@ chip_specific_stack_frame:              /* First add any chip specific registers
     addi t0, t0, -1                     /* Decrement the count of chip specific registers remaining. */
     j chip_specific_stack_frame         /* Until no more chip specific registers. */
 1:
+    csrr t0, mstatus                    /* Obtain current mstatus value. */
+    andi t0, t0, ~0x8                   /* Ensure interrupts are disabled when the stack is restored within an ISR.  Required when a task is created after the scheduler has been started, otherwise interrupts would be disabled anyway. */
+    addi t1, x0, 0x188                  /* Generate the value 0x1880, which are the MPIE=1 and MPP=M_Mode in mstatus. */
+    slli t1, t1, 4
+    or t0, t0, t1                       /* Set MPIE and MPP bits in mstatus value. */
+
+#if( configENABLE_FPU == 1 )
+    /* Mark the FPU as clean in the mstatus value. */
+    li t1, ~MSTATUS_FS_MASK
+    and t0, t0, t1
+    li t1, MSTATUS_FS_CLEAN
+    or t0, t0, t1
+#endif
+
+#if( configENABLE_VPU == 1 )
+    /* Mark the VPU as clean in the mstatus value. */
+    li t1, ~MSTATUS_VS_MASK
+    and t0, t0, t1
+    li t1, MSTATUS_VS_CLEAN
+    or t0, t0, t1
+#endif
+
+    addi a0, a0, -portWORD_SIZE
+    store_x t0, 0(a0)                   /* mstatus onto the stack. */
+
     addi a0, a0, -portWORD_SIZE
     store_x a1, 0(a0)                   /* mret value (pxCode parameter) onto the stack. */
     ret
@@ -235,46 +256,46 @@ xPortStartFirstTask:
 
     load_x  x1, 0( sp ) /* Note for starting the scheduler the exception return address is used as the function return address. */
 
+    load_x  x5, 1 * portWORD_SIZE( sp ) /* Initial mstatus into x5 (t0). */
+    addi    x5, x5, 0x08                /* Set MIE bit so the first task starts with interrupts enabled - required as returns with ret not eret. */
+    csrw    mstatus, x5                 /* Interrupts enabled from here! */
+
     portasmRESTORE_ADDITIONAL_REGISTERS /* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
 
-    load_x  x7, 4 * portWORD_SIZE( sp )     /* t2 */
+    load_x  x7,  5  * portWORD_SIZE( sp )   /* t2 */
-    load_x  x8, 5 * portWORD_SIZE( sp )     /* s0/fp */
+    load_x  x8,  6  * portWORD_SIZE( sp )   /* s0/fp */
-    load_x  x9, 6 * portWORD_SIZE( sp )     /* s1 */
+    load_x  x9,  7  * portWORD_SIZE( sp )   /* s1 */
-    load_x  x10, 7 * portWORD_SIZE( sp )    /* a0 */
+    load_x  x10, 8  * portWORD_SIZE( sp )   /* a0 */
-    load_x  x11, 8 * portWORD_SIZE( sp )    /* a1 */
+    load_x  x11, 9  * portWORD_SIZE( sp )   /* a1 */
-    load_x  x12, 9 * portWORD_SIZE( sp )    /* a2 */
+    load_x  x12, 10 * portWORD_SIZE( sp )   /* a2 */
-    load_x  x13, 10 * portWORD_SIZE( sp )   /* a3 */
+    load_x  x13, 11 * portWORD_SIZE( sp )   /* a3 */
-    load_x  x14, 11 * portWORD_SIZE( sp )   /* a4 */
+    load_x  x14, 12 * portWORD_SIZE( sp )   /* a4 */
-    load_x  x15, 12 * portWORD_SIZE( sp )   /* a5 */
+    load_x  x15, 13 * portWORD_SIZE( sp )   /* a5 */
 #ifndef __riscv_32e
-    load_x  x16, 13 * portWORD_SIZE( sp )   /* a6 */
+    load_x  x16, 14 * portWORD_SIZE( sp )   /* a6 */
-    load_x  x17, 14 * portWORD_SIZE( sp )   /* a7 */
+    load_x  x17, 15 * portWORD_SIZE( sp )   /* a7 */
-    load_x  x18, 15 * portWORD_SIZE( sp )   /* s2 */
+    load_x  x18, 16 * portWORD_SIZE( sp )   /* s2 */
-    load_x  x19, 16 * portWORD_SIZE( sp )   /* s3 */
+    load_x  x19, 17 * portWORD_SIZE( sp )   /* s3 */
-    load_x  x20, 17 * portWORD_SIZE( sp )   /* s4 */
+    load_x  x20, 18 * portWORD_SIZE( sp )   /* s4 */
-    load_x  x21, 18 * portWORD_SIZE( sp )   /* s5 */
+    load_x  x21, 19 * portWORD_SIZE( sp )   /* s5 */
-    load_x  x22, 19 * portWORD_SIZE( sp )   /* s6 */
+    load_x  x22, 20 * portWORD_SIZE( sp )   /* s6 */
-    load_x  x23, 20 * portWORD_SIZE( sp )   /* s7 */
+    load_x  x23, 21 * portWORD_SIZE( sp )   /* s7 */
-    load_x  x24, 21 * portWORD_SIZE( sp )   /* s8 */
+    load_x  x24, 22 * portWORD_SIZE( sp )   /* s8 */
-    load_x  x25, 22 * portWORD_SIZE( sp )   /* s9 */
+    load_x  x25, 23 * portWORD_SIZE( sp )   /* s9 */
-    load_x  x26, 23 * portWORD_SIZE( sp )   /* s10 */
+    load_x  x26, 24 * portWORD_SIZE( sp )   /* s10 */
-    load_x  x27, 24 * portWORD_SIZE( sp )   /* s11 */
+    load_x  x27, 25 * portWORD_SIZE( sp )   /* s11 */
-    load_x  x28, 25 * portWORD_SIZE( sp )   /* t3 */
+    load_x  x28, 26 * portWORD_SIZE( sp )   /* t3 */
-    load_x  x29, 26 * portWORD_SIZE( sp )   /* t4 */
+    load_x  x29, 27 * portWORD_SIZE( sp )   /* t4 */
-    load_x  x30, 27 * portWORD_SIZE( sp )   /* t5 */
+    load_x  x30, 28 * portWORD_SIZE( sp )   /* t5 */
-    load_x  x31, 28 * portWORD_SIZE( sp )   /* t6 */
+    load_x  x31, 29 * portWORD_SIZE( sp )   /* t6 */
 #endif
 
     load_x  x5, portCRITICAL_NESTING_OFFSET * portWORD_SIZE( sp )    /* Obtain xCriticalNesting value for this task from task's stack. */
     load_x  x6, pxCriticalNesting           /* Load the address of xCriticalNesting into x6. */
     store_x x5, 0( x6 )                     /* Restore the critical nesting value for this task. */
 
-    load_x  x5, portMSTATUS_OFFSET * portWORD_SIZE( sp )    /* Initial mstatus into x5 (t0). */
+    load_x  x5, 3 * portWORD_SIZE( sp )     /* Initial x5 (t0) value. */
-    addi    x5, x5, 0x08                    /* Set MIE bit so the first task starts with interrupts enabled - required as returns with ret not eret. */
+    load_x  x6, 4 * portWORD_SIZE( sp )     /* Initial x6 (t1) value. */
-    csrrw   x0, mstatus, x5                 /* Interrupts enabled from here! */
-
-    load_x  x5, 2 * portWORD_SIZE( sp )     /* Initial x5 (t0) value. */
-    load_x  x6, 3 * portWORD_SIZE( sp )     /* Initial x6 (t1) value. */
 
     addi    sp, sp, portCONTEXT_SIZE
     ret

portable/GCC/RISC-V/portContext.h

@@ -29,6 +29,14 @@
 #ifndef PORTCONTEXT_H
 #define PORTCONTEXT_H
 
+#ifndef configENABLE_FPU
+    #define configENABLE_FPU 0
+#endif
+
+#ifndef configENABLE_VPU
+    #define configENABLE_VPU 0
+#endif
+
 #if __riscv_xlen == 64
     #define portWORD_SIZE    8
     #define store_x          sd
@@ -50,65 +58,311 @@
  * notes at the top of portASM.S file. */
 #ifdef __riscv_32e
     #define portCONTEXT_SIZE               ( 15 * portWORD_SIZE )
-    #define portCRITICAL_NESTING_OFFSET    13
+    #define portCRITICAL_NESTING_OFFSET    14
-    #define portMSTATUS_OFFSET             14
 #else
     #define portCONTEXT_SIZE               ( 31 * portWORD_SIZE )
-    #define portCRITICAL_NESTING_OFFSET    29
+    #define portCRITICAL_NESTING_OFFSET    30
-    #define portMSTATUS_OFFSET             30
 #endif
 
+#if ( configENABLE_FPU == 1 )
+    /* Bit [14:13] in the mstatus encode the status of FPU state which is one of
+     * the following values:
+     * 1. Value: 0, Meaning: Off.
+     * 2. Value: 1, Meaning: Initial.
+     * 3. Value: 2, Meaning: Clean.
+     * 4. Value: 3, Meaning: Dirty.
+     */
+    #define MSTATUS_FS_MASK                 0x6000
+    #define MSTATUS_FS_INITIAL              0x2000
+    #define MSTATUS_FS_CLEAN                0x4000
+    #define MSTATUS_FS_DIRTY                0x6000
+    #define MSTATUS_FS_OFFSET               13
+
+    #ifdef __riscv_fdiv
+        #if __riscv_flen == 32
+            #define load_f                  flw
+            #define store_f                 fsw
+        #elif __riscv_flen == 64
+            #define load_f                  fld
+            #define store_f                 fsd
+        #else
+            #error Assembler did not define __riscv_flen
+        #endif
+
+        #define portFPU_REG_SIZE                ( __riscv_flen / 8 )
+        #define portFPU_REG_COUNT               33 /* 32 Floating point registers plus one CSR. */
+        #define portFPU_REG_OFFSET( regIndex )  ( ( 2 * portWORD_SIZE ) + ( regIndex * portFPU_REG_SIZE ) )
+        #define portFPU_CONTEXT_SIZE            ( portFPU_REG_SIZE * portFPU_REG_COUNT )
+    #else
+        #error configENABLE_FPU must not be set to 1 if the hardware does not have FPU
+    #endif
+#endif
+
+#if ( configENABLE_VPU == 1 )
+    /* Bit [10:9] in the mstatus encode the status of VPU state which is one of
+     * the following values:
+     * 1. Value: 0, Meaning: Off.
+     * 2. Value: 1, Meaning: Initial.
+     * 3. Value: 2, Meaning: Clean.
+     * 4. Value: 3, Meaning: Dirty.
+     */
+    #define MSTATUS_VS_MASK                 0x600
+    #define MSTATUS_VS_INITIAL              0x200
+    #define MSTATUS_VS_CLEAN                0x400
+    #define MSTATUS_VS_DIRTY                0x600
+    #define MSTATUS_VS_OFFSET               9
+
+    #ifndef __riscv_vector
+        #error configENABLE_VPU must not be set to 1 if the hardware does not have VPU
+    #endif
+#endif
 /*-----------------------------------------------------------*/
 
 .extern pxCurrentTCB
-   .extern xISRStackTop
+.extern xISRStackTop
-   .extern xCriticalNesting
+.extern xCriticalNesting
-   .extern pxCriticalNesting
+.extern pxCriticalNesting
+/*-----------------------------------------------------------*/
+
+    .macro portcontexSAVE_FPU_CONTEXT
+addi sp, sp, -( portFPU_CONTEXT_SIZE )
+/* Store the FPU registers. */
+store_f f0,  portFPU_REG_OFFSET( 0  )( sp )
+store_f f1,  portFPU_REG_OFFSET( 1  )( sp )
+store_f f2,  portFPU_REG_OFFSET( 2  )( sp )
+store_f f3,  portFPU_REG_OFFSET( 3  )( sp )
+store_f f4,  portFPU_REG_OFFSET( 4  )( sp )
+store_f f5,  portFPU_REG_OFFSET( 5  )( sp )
+store_f f6,  portFPU_REG_OFFSET( 6  )( sp )
+store_f f7,  portFPU_REG_OFFSET( 7  )( sp )
+store_f f8,  portFPU_REG_OFFSET( 8  )( sp )
+store_f f9,  portFPU_REG_OFFSET( 9  )( sp )
+store_f f10, portFPU_REG_OFFSET( 10 )( sp )
+store_f f11, portFPU_REG_OFFSET( 11 )( sp )
+store_f f12, portFPU_REG_OFFSET( 12 )( sp )
+store_f f13, portFPU_REG_OFFSET( 13 )( sp )
+store_f f14, portFPU_REG_OFFSET( 14 )( sp )
+store_f f15, portFPU_REG_OFFSET( 15 )( sp )
+store_f f16, portFPU_REG_OFFSET( 16 )( sp )
+store_f f17, portFPU_REG_OFFSET( 17 )( sp )
+store_f f18, portFPU_REG_OFFSET( 18 )( sp )
+store_f f19, portFPU_REG_OFFSET( 19 )( sp )
+store_f f20, portFPU_REG_OFFSET( 20 )( sp )
+store_f f21, portFPU_REG_OFFSET( 21 )( sp )
+store_f f22, portFPU_REG_OFFSET( 22 )( sp )
+store_f f23, portFPU_REG_OFFSET( 23 )( sp )
+store_f f24, portFPU_REG_OFFSET( 24 )( sp )
+store_f f25, portFPU_REG_OFFSET( 25 )( sp )
+store_f f26, portFPU_REG_OFFSET( 26 )( sp )
+store_f f27, portFPU_REG_OFFSET( 27 )( sp )
+store_f f28, portFPU_REG_OFFSET( 28 )( sp )
+store_f f29, portFPU_REG_OFFSET( 29 )( sp )
+store_f f30, portFPU_REG_OFFSET( 30 )( sp )
+store_f f31, portFPU_REG_OFFSET( 31 )( sp )
+csrr t0, fcsr
+store_x t0,  portFPU_REG_OFFSET( 32 )( sp )
+    .endm
+/*-----------------------------------------------------------*/
+
+    .macro portcontextRESTORE_FPU_CONTEXT
+/* Restore the FPU registers. */
+load_f f0,  portFPU_REG_OFFSET( 0  )( sp )
+load_f f1,  portFPU_REG_OFFSET( 1  )( sp )
+load_f f2,  portFPU_REG_OFFSET( 2  )( sp )
+load_f f3,  portFPU_REG_OFFSET( 3  )( sp )
+load_f f4,  portFPU_REG_OFFSET( 4  )( sp )
+load_f f5,  portFPU_REG_OFFSET( 5  )( sp )
+load_f f6,  portFPU_REG_OFFSET( 6  )( sp )
+load_f f7,  portFPU_REG_OFFSET( 7  )( sp )
+load_f f8,  portFPU_REG_OFFSET( 8  )( sp )
+load_f f9,  portFPU_REG_OFFSET( 9  )( sp )
+load_f f10, portFPU_REG_OFFSET( 10 )( sp )
+load_f f11, portFPU_REG_OFFSET( 11 )( sp )
+load_f f12, portFPU_REG_OFFSET( 12 )( sp )
+load_f f13, portFPU_REG_OFFSET( 13 )( sp )
+load_f f14, portFPU_REG_OFFSET( 14 )( sp )
+load_f f15, portFPU_REG_OFFSET( 15 )( sp )
+load_f f16, portFPU_REG_OFFSET( 16 )( sp )
+load_f f17, portFPU_REG_OFFSET( 17 )( sp )
+load_f f18, portFPU_REG_OFFSET( 18 )( sp )
+load_f f19, portFPU_REG_OFFSET( 19 )( sp )
+load_f f20, portFPU_REG_OFFSET( 20 )( sp )
+load_f f21, portFPU_REG_OFFSET( 21 )( sp )
+load_f f22, portFPU_REG_OFFSET( 22 )( sp )
+load_f f23, portFPU_REG_OFFSET( 23 )( sp )
+load_f f24, portFPU_REG_OFFSET( 24 )( sp )
+load_f f25, portFPU_REG_OFFSET( 25 )( sp )
+load_f f26, portFPU_REG_OFFSET( 26 )( sp )
+load_f f27, portFPU_REG_OFFSET( 27 )( sp )
+load_f f28, portFPU_REG_OFFSET( 28 )( sp )
+load_f f29, portFPU_REG_OFFSET( 29 )( sp )
+load_f f30, portFPU_REG_OFFSET( 30 )( sp )
+load_f f31, portFPU_REG_OFFSET( 31 )( sp )
+load_x t0,  portFPU_REG_OFFSET( 32 )( sp )
+csrw fcsr, t0
+addi sp, sp, ( portFPU_CONTEXT_SIZE )
+    .endm
+/*-----------------------------------------------------------*/
+
+    .macro portcontexSAVE_VPU_CONTEXT
+/* Un-reserve the space reserved for mstatus and epc. */
+add sp, sp, ( 2 * portWORD_SIZE )
+
+csrr t0, vlenb /* t0 = vlenb. vlenb is the length of each vector register in bytes. */
+slli t0, t0, 3 /* t0 = vlenb * 8. t0 now contains the space required to store 8 vector registers. */
+neg  t0, t0
+
+/* Store the vector registers in group of 8. */
+add     sp, sp, t0
+vs8r.v  v0, (sp)    /* Store v0-v7. */
+add     sp, sp, t0
+vs8r.v  v8, (sp)    /* Store v8-v15. */
+add     sp, sp, t0
+vs8r.v  v16, (sp)   /* Store v16-v23. */
+add     sp, sp, t0
+vs8r.v  v24, (sp)   /* Store v24-v31. */
+
+/* Store the VPU CSRs. */
+addi    sp, sp, -( 4 * portWORD_SIZE )
+csrr    t0, vstart
+store_x t0, 0 * portWORD_SIZE( sp )
+csrr    t0, vcsr
+store_x t0, 1 * portWORD_SIZE( sp )
+csrr    t0, vl
+store_x t0, 2 * portWORD_SIZE( sp )
+csrr    t0, vtype
+store_x t0, 3 * portWORD_SIZE( sp )
+
+/* Re-reserve the space for mstatus and epc. */
+add sp, sp, -( 2 * portWORD_SIZE )
+    .endm
+/*-----------------------------------------------------------*/
+
+    .macro portcontextRESTORE_VPU_CONTEXT
+/* Un-reserve the space reserved for mstatus and epc. */
+add sp, sp, ( 2 * portWORD_SIZE )
+
+/* Restore the VPU CSRs. */
+load_x  t0, 0  * portWORD_SIZE( sp )
+csrw    vstart, t0
+load_x  t0, 1 * portWORD_SIZE( sp )
+csrw    vcsr, t0
+load_x  t0, 2 * portWORD_SIZE( sp )
+load_x  t1, 3 * portWORD_SIZE( sp )
+vsetvl  x0, t0, t1 /* vlen and vtype can only be updated by using vset*vl* instructions. */
+addi    sp, sp, ( 4 * portWORD_SIZE )
+
+csrr t0, vlenb /* t0 = vlenb. vlenb is the length of each vector register in bytes. */
+slli t0, t0, 3 /* t0 = vlenb * 8. t0 now contains the space required to store 8 vector registers. */
+
+/* Restore the vector registers. */
+vl8r.v  v24, (sp)
+add     sp, sp, t0
+vl8r.v  v16, (sp)
+add     sp, sp, t0
+vl8r.v  v8, (sp)
+add     sp, sp, t0
+vl8r.v  v0, (sp)
+add     sp, sp, t0
+
+/* Re-reserve the space for mstatus and epc. */
+add sp, sp, -( 2 * portWORD_SIZE )
+    .endm
 /*-----------------------------------------------------------*/
 
    .macro portcontextSAVE_CONTEXT_INTERNAL
 addi sp, sp, -portCONTEXT_SIZE
-store_x x1, 1 * portWORD_SIZE( sp )
+store_x x1,  2  * portWORD_SIZE( sp )
-store_x x5, 2 * portWORD_SIZE( sp )
+store_x x5,  3  * portWORD_SIZE( sp )
-store_x x6, 3 * portWORD_SIZE( sp )
+store_x x6,  4  * portWORD_SIZE( sp )
-store_x x7, 4 * portWORD_SIZE( sp )
+store_x x7,  5  * portWORD_SIZE( sp )
-store_x x8, 5 * portWORD_SIZE( sp )
+store_x x8,  6  * portWORD_SIZE( sp )
-store_x x9, 6 * portWORD_SIZE( sp )
+store_x x9,  7  * portWORD_SIZE( sp )
-store_x x10, 7 * portWORD_SIZE( sp )
+store_x x10, 8  * portWORD_SIZE( sp )
-store_x x11, 8 * portWORD_SIZE( sp )
+store_x x11, 9  * portWORD_SIZE( sp )
-store_x x12, 9 * portWORD_SIZE( sp )
+store_x x12, 10 * portWORD_SIZE( sp )
-store_x x13, 10 * portWORD_SIZE( sp )
+store_x x13, 11 * portWORD_SIZE( sp )
-store_x x14, 11 * portWORD_SIZE( sp )
+store_x x14, 12 * portWORD_SIZE( sp )
-store_x x15, 12 * portWORD_SIZE( sp )
+store_x x15, 13 * portWORD_SIZE( sp )
 #ifndef __riscv_32e
-    store_x x16, 13 * portWORD_SIZE( sp )
+    store_x x16, 14 * portWORD_SIZE( sp )
-    store_x x17, 14 * portWORD_SIZE( sp )
+    store_x x17, 15 * portWORD_SIZE( sp )
-    store_x x18, 15 * portWORD_SIZE( sp )
+    store_x x18, 16 * portWORD_SIZE( sp )
-    store_x x19, 16 * portWORD_SIZE( sp )
+    store_x x19, 17 * portWORD_SIZE( sp )
-    store_x x20, 17 * portWORD_SIZE( sp )
+    store_x x20, 18 * portWORD_SIZE( sp )
-    store_x x21, 18 * portWORD_SIZE( sp )
+    store_x x21, 19 * portWORD_SIZE( sp )
-    store_x x22, 19 * portWORD_SIZE( sp )
+    store_x x22, 20 * portWORD_SIZE( sp )
-    store_x x23, 20 * portWORD_SIZE( sp )
+    store_x x23, 21 * portWORD_SIZE( sp )
-    store_x x24, 21 * portWORD_SIZE( sp )
+    store_x x24, 22 * portWORD_SIZE( sp )
-    store_x x25, 22 * portWORD_SIZE( sp )
+    store_x x25, 23 * portWORD_SIZE( sp )
-    store_x x26, 23 * portWORD_SIZE( sp )
+    store_x x26, 24 * portWORD_SIZE( sp )
-    store_x x27, 24 * portWORD_SIZE( sp )
+    store_x x27, 25 * portWORD_SIZE( sp )
-    store_x x28, 25 * portWORD_SIZE( sp )
+    store_x x28, 26 * portWORD_SIZE( sp )
-    store_x x29, 26 * portWORD_SIZE( sp )
+    store_x x29, 27 * portWORD_SIZE( sp )
-    store_x x30, 27 * portWORD_SIZE( sp )
+    store_x x30, 28 * portWORD_SIZE( sp )
-    store_x x31, 28 * portWORD_SIZE( sp )
+    store_x x31, 29 * portWORD_SIZE( sp )
 #endif /* ifndef __riscv_32e */
 
 load_x t0, xCriticalNesting                                   /* Load the value of xCriticalNesting into t0. */
 store_x t0, portCRITICAL_NESTING_OFFSET * portWORD_SIZE( sp ) /* Store the critical nesting value to the stack. */
 
+#if( configENABLE_FPU == 1 )
+    csrr t0, mstatus
+    srl t1, t0, MSTATUS_FS_OFFSET
+    andi t1, t1, 3
+    addi t2, x0, 3
+    bne t1, t2, 1f /* If FPU status is not dirty, do not save FPU registers. */
 
-csrr t0, mstatus /* Required for MPIE bit. */
+    portcontexSAVE_FPU_CONTEXT
-store_x t0, portMSTATUS_OFFSET * portWORD_SIZE( sp )
+1:
+#endif
 
+#if( configENABLE_VPU == 1 )
+    csrr t0, mstatus
+    srl t1, t0, MSTATUS_VS_OFFSET
+    andi t1, t1, 3
+    addi t2, x0, 3
+    bne t1, t2, 2f /* If VPU status is not dirty, do not save FPU registers. */
+
+    portcontexSAVE_VPU_CONTEXT
+2:
+#endif
 
 portasmSAVE_ADDITIONAL_REGISTERS /* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
 
+csrr t0, mstatus
+store_x t0, 1 * portWORD_SIZE( sp )
+
+#if( configENABLE_FPU == 1 )
+    /* Mark the FPU as clean, if it was dirty and we saved FPU registers. */
+    srl t1, t0, MSTATUS_FS_OFFSET
+    andi t1, t1, 3
+    addi t2, x0, 3
+    bne t1, t2, 3f
+
+    li t1, ~MSTATUS_FS_MASK
+    and t0, t0, t1
+    li t1, MSTATUS_FS_CLEAN
+    or t0, t0, t1
+    csrw mstatus, t0
+3:
+#endif
+
+#if( configENABLE_VPU == 1 )
+    /* Mark the VPU as clean, if it was dirty and we saved VPU registers. */
+    srl t1, t0, MSTATUS_VS_OFFSET
+    andi t1, t1, 3
+    addi t2, x0, 3
+    bne t1, t2, 4f
+
+    li t1, ~MSTATUS_VS_MASK
+    and t0, t0, t1
+    li t1, MSTATUS_VS_CLEAN
+    or t0, t0, t1
+    csrw mstatus, t0
+4:
+#endif
+
 load_x t0, pxCurrentTCB          /* Load pxCurrentTCB. */
 store_x sp, 0 ( t0 )             /* Write sp to first TCB member. */
 
@@ -142,46 +396,68 @@ load_x sp, 0 ( t1 )     /* Read sp from first TCB member. */
 load_x t0, 0 ( sp )
 csrw mepc, t0
 
+/* Restore mstatus register. */
+load_x t0, 1 * portWORD_SIZE( sp )
+csrw mstatus, t0
+
 /* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
 portasmRESTORE_ADDITIONAL_REGISTERS
 
-/* Load mstatus with the interrupt enable bits used by the task. */
+#if( configENABLE_VPU == 1 )
-load_x t0, portMSTATUS_OFFSET * portWORD_SIZE( sp )
+    csrr t0, mstatus
-csrw mstatus, t0                                             /* Required for MPIE bit. */
+    srl t1, t0, MSTATUS_VS_OFFSET
+    andi t1, t1, 3
+    addi t2, x0, 3
+    bne t1, t2, 5f /* If VPU status is not dirty, do not restore VPU registers. */
+
+    portcontextRESTORE_VPU_CONTEXT
+5:
+#endif /* ifdef portasmSTORE_VPU_CONTEXT */
+
+#if( configENABLE_FPU == 1 )
+    csrr t0, mstatus
+    srl t1, t0, MSTATUS_FS_OFFSET
+    andi t1, t1, 3
+    addi t2, x0, 3
+    bne t1, t2, 6f /* If FPU status is not dirty, do not restore FPU registers. */
+
+    portcontextRESTORE_FPU_CONTEXT
+6:
+#endif /* ifdef portasmSTORE_FPU_CONTEXT */
 
 load_x t0, portCRITICAL_NESTING_OFFSET * portWORD_SIZE( sp ) /* Obtain xCriticalNesting value for this task from task's stack. */
 load_x t1, pxCriticalNesting                                 /* Load the address of xCriticalNesting into t1. */
 store_x t0, 0 ( t1 )                                         /* Restore the critical nesting value for this task. */
 
-load_x x1, 1 * portWORD_SIZE( sp )
+load_x x1,  2  * portWORD_SIZE( sp )
-load_x x5, 2 * portWORD_SIZE( sp )
+load_x x5,  3  * portWORD_SIZE( sp )
-load_x x6, 3 * portWORD_SIZE( sp )
+load_x x6,  4  * portWORD_SIZE( sp )
-load_x x7, 4 * portWORD_SIZE( sp )
+load_x x7,  5  * portWORD_SIZE( sp )
-load_x x8, 5 * portWORD_SIZE( sp )
+load_x x8,  6  * portWORD_SIZE( sp )
-load_x x9, 6 * portWORD_SIZE( sp )
+load_x x9,  7  * portWORD_SIZE( sp )
-load_x x10, 7 * portWORD_SIZE( sp )
+load_x x10, 8  * portWORD_SIZE( sp )
-load_x x11, 8 * portWORD_SIZE( sp )
+load_x x11, 9  * portWORD_SIZE( sp )
-load_x x12, 9 * portWORD_SIZE( sp )
+load_x x12, 10 * portWORD_SIZE( sp )
-load_x x13, 10 * portWORD_SIZE( sp )
+load_x x13, 11 * portWORD_SIZE( sp )
-load_x x14, 11 * portWORD_SIZE( sp )
+load_x x14, 12 * portWORD_SIZE( sp )
-load_x x15, 12 * portWORD_SIZE( sp )
+load_x x15, 13 * portWORD_SIZE( sp )
 #ifndef __riscv_32e
-    load_x x16, 13 * portWORD_SIZE( sp )
+    load_x x16, 14 * portWORD_SIZE( sp )
-    load_x x17, 14 * portWORD_SIZE( sp )
+    load_x x17, 15 * portWORD_SIZE( sp )
-    load_x x18, 15 * portWORD_SIZE( sp )
+    load_x x18, 16 * portWORD_SIZE( sp )
-    load_x x19, 16 * portWORD_SIZE( sp )
+    load_x x19, 17 * portWORD_SIZE( sp )
-    load_x x20, 17 * portWORD_SIZE( sp )
+    load_x x20, 18 * portWORD_SIZE( sp )
-    load_x x21, 18 * portWORD_SIZE( sp )
+    load_x x21, 19 * portWORD_SIZE( sp )
-    load_x x22, 19 * portWORD_SIZE( sp )
+    load_x x22, 20 * portWORD_SIZE( sp )
-    load_x x23, 20 * portWORD_SIZE( sp )
+    load_x x23, 21 * portWORD_SIZE( sp )
-    load_x x24, 21 * portWORD_SIZE( sp )
+    load_x x24, 22 * portWORD_SIZE( sp )
-    load_x x25, 22 * portWORD_SIZE( sp )
+    load_x x25, 23 * portWORD_SIZE( sp )
-    load_x x26, 23 * portWORD_SIZE( sp )
+    load_x x26, 24 * portWORD_SIZE( sp )
-    load_x x27, 24 * portWORD_SIZE( sp )
+    load_x x27, 25 * portWORD_SIZE( sp )
-    load_x x28, 25 * portWORD_SIZE( sp )
+    load_x x28, 26 * portWORD_SIZE( sp )
-    load_x x29, 26 * portWORD_SIZE( sp )
+    load_x x29, 27 * portWORD_SIZE( sp )
-    load_x x30, 27 * portWORD_SIZE( sp )
+    load_x x30, 28 * portWORD_SIZE( sp )
-    load_x x31, 28 * portWORD_SIZE( sp )
+    load_x x31, 29 * portWORD_SIZE( sp )
 #endif /* ifndef __riscv_32e */
 addi sp, sp, portCONTEXT_SIZE
 

portable/IAR/ARM_CM23/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM23_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM33/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM33_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM35P/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM35P_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM4F_MPU/port.c

@@ -1,6 +1,8 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * Copyright 2025 Arm Limited and/or its affiliates
+ * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
  *
@@ -459,7 +461,7 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
             /* Declaration when these variable are defined in code instead of being
@@ -494,10 +496,14 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
             {
                 /* Extended frame i.e. FPU in use. */
-                ulStackFrameSize = 26;
+                ulHardwareSavedExceptionFrameSize = 26;
                 __asm volatile (
                     " vpush {s0}         \n" /* Trigger lazy stacking. */
                     " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -507,14 +513,14 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
             else
             {
                 /* Standard frame i.e. FPU not in use. */
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -532,7 +538,7 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Store the value of the Link Register before the SVC was raised.
              * It contains the address of the caller of the System Call entry
@@ -586,7 +592,7 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
             /* Declaration when these variable are defined in code instead of being
@@ -617,10 +623,14 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
             {
                 /* Extended frame i.e. FPU in use. */
-                ulStackFrameSize = 26;
+                ulHardwareSavedExceptionFrameSize = 26;
                 __asm volatile (
                     " vpush {s0}         \n" /* Trigger lazy stacking. */
                     " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -630,14 +640,14 @@ void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
             else
             {
                 /* Standard frame i.e. FPU not in use. */
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM55/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM55_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM85/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/ARM_CM85_NTZ/non_secure/port.c

@@ -1,7 +1,7 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * Copyright 2024 Arm Limited and/or its affiliates
+ * Copyright 2024-2025 Arm Limited and/or its affiliates
  * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
@@ -230,7 +230,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( portARMV8M_MINOR_VERSION >= 1 )
 
-/* Enable Privileged eXecute Never MPU attribute for the selected memory
+    /* Enable Privileged eXecute Never MPU attribute for the selected memory
      * region. */
     #define portMPU_RLAR_PRIVILEGED_EXECUTE_NEVER    ( 1UL << 4UL )
 #endif /* portARMV8M_MINOR_VERSION >= 1 */
@@ -241,9 +241,6 @@ typedef void ( * portISR_t )( void );
 /* Enable MPU. */
 #define portMPU_ENABLE_BIT                    ( 1UL << 0UL )
 
-/* Expected value of the portMPU_TYPE register. */
-#define portEXPECTED_MPU_TYPE_VALUE           ( configTOTAL_MPU_REGIONS << 8UL )
-
 /* Extract first address of the MPU region as encoded in the
  * RBAR (Region Base Address Register) value. */
 #define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
@@ -291,7 +288,7 @@ typedef void ( * portISR_t )( void );
 
 #if ( configRUN_FREERTOS_SECURE_ONLY == 1 )
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         FD
@@ -308,7 +305,7 @@ typedef void ( * portISR_t )( void );
     #define portINITIAL_EXC_RETURN    ( 0xfffffffd )
 #else
 
-/**
+    /**
      * @brief Initial EXC_RETURN value.
      *
      *     FF         FF         FF         BC
@@ -401,7 +398,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Extract MPU region's access permissions from the Region Base Address
      * Register (RBAR) value.
      *
@@ -414,7 +411,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Setup the Memory Protection Unit (MPU).
      */
     static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
@@ -422,7 +419,7 @@ static void prvTaskExitError( void );
 
 #if ( configENABLE_FPU == 1 )
 
-/**
+    /**
      * @brief Setup the Floating Point Unit (FPU).
      */
     static void prvSetupFPU( void ) PRIVILEGED_FUNCTION;
@@ -430,7 +427,7 @@ static void prvTaskExitError( void );
 
 #if ( ( configENABLE_PAC == 1 ) || ( configENABLE_BTI == 1 ) )
 
-/**
+    /**
      * @brief Configures PACBTI features.
      *
      * This function configures the Pointer Authentication, and Branch Target
@@ -491,7 +488,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the system call stack so that upon returning from
      * SVC, the system call stack is used.
      *
@@ -507,7 +504,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Raise SVC for exiting from a system call.
      */
     void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
@@ -516,7 +513,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief Sets up the task stack so that upon returning from
      * SVC, the task stack is used again.
      *
@@ -530,7 +527,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( configENABLE_MPU == 1 )
 
-/**
+    /**
      * @brief Checks whether or not the calling task is privileged.
      *
      * @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
@@ -542,7 +539,7 @@ portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIV
 
 #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
 
-/**
+    /**
      * @brief This variable is set to pdTRUE when the scheduler is started.
      */
     PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
@@ -557,7 +554,7 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configENABLE_TRUSTZONE == 1 )
 
-/**
+    /**
      * @brief Saved as part of the task context to indicate which context the
      * task is using on the secure side.
      */
@@ -579,18 +576,18 @@ PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
 
 #if ( configUSE_TICKLESS_IDLE == 1 )
 
-/**
+    /**
      * @brief The number of SysTick increments that make up one tick period.
      */
     PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
 
-/**
+    /**
      * @brief The maximum number of tick periods that can be suppressed is
      * limited by the 24 bit resolution of the SysTick timer.
      */
     PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
 
-/**
+    /**
      * @brief Compensate for the CPU cycles that pass while the SysTick is
      * stopped (low power functionality only).
      */
@@ -925,12 +922,6 @@ static void prvTaskExitError( void )
         /* The only permitted number of regions are 8 or 16. */
         configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_REGIONS == 16 ) );
 
-        /* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
-        configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
-
-        /* Check that the MPU is present. */
-        if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
-        {
         /* MAIR0 - Index 0. */
         portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
         /* MAIR0 - Index 1. */
@@ -983,7 +974,6 @@ static void prvTaskExitError( void )
          * regions have privileged access. */
         portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
     }
-    }
 
 #endif /* configENABLE_MPU */
 /*-----------------------------------------------------------*/
@@ -1210,7 +1200,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1246,12 +1236,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1261,20 +1255,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -1310,7 +1304,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Record if the hardware used padding to force the stack pointer
              * to be double word aligned. */
@@ -1360,7 +1354,7 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i;
 
         #if defined( __ARMCC_VERSION )
 
@@ -1392,12 +1386,16 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             #if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) )
             {
                 if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
                 {
                     /* Extended frame i.e. FPU in use. */
-                    ulStackFrameSize = 26;
+                    ulHardwareSavedExceptionFrameSize = 26;
                     __asm volatile (
                         " vpush {s0}         \n" /* Trigger lazy stacking. */
                         " vpop  {s0}         \n" /* Nullify the affect of the above instruction. */
@@ -1407,20 +1405,20 @@ void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTIO
                 else
                 {
                     /* Standard frame i.e. FPU not in use. */
-                    ulStackFrameSize = 8;
+                    ulHardwareSavedExceptionFrameSize = 8;
                 }
             }
             #else /* if ( ( configENABLE_FPU == 1 ) || ( configENABLE_MVE == 1 ) ) */
             {
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
             #endif /* configENABLE_FPU || configENABLE_MVE */
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/IAR/RISC-V/port.c

@@ -98,7 +98,7 @@ void vPortSetupTimerInterrupt( void ) __attribute__( ( weak ) );
 uint64_t ullNextTime = 0ULL;
 const uint64_t * pullNextTime = &ullNextTime;
 const size_t uxTimerIncrementsForOneTick = ( size_t ) ( ( configCPU_CLOCK_HZ ) / ( configTICK_RATE_HZ ) ); /* Assumes increment won't go over 32-bits. */
-uint64_t const ullMachineTimerCompareRegisterBase = configMTIMECMP_BASE_ADDRESS;
+UBaseType_t const ullMachineTimerCompareRegisterBase = configMTIMECMP_BASE_ADDRESS;
 volatile uint64_t * pullMachineTimerCompareRegister = NULL;
 
 /* Holds the critical nesting value - deliberately non-zero at start up to

portable/IAR/RL78/portmacro.h

@@ -187,7 +187,7 @@
               * ; * memory mode) registers the _usCriticalNesting value and the Stack Pointer
               * ; * of the active Task onto the task stack.
               * ; *---------------------------------------------------------------------------*/
-    portSAVE_CONTEXT MACRO
+portSAVE_CONTEXT MACRO
     PUSH AX; /* Save AX Register to stack. */
     PUSH HL
     #if  __CODE_MODEL__ == __CODE_MODEL_FAR__
@@ -217,7 +217,7 @@
  * ; * general purpose registers and the CS and ES (only in __far memory mode)
  * ; * of the selected task from the task stack.
  * ; *---------------------------------------------------------------------------*/
-    portRESTORE_CONTEXT MACRO
+portRESTORE_CONTEXT MACRO
     MOVW AX, _pxCurrentTCB; /* Restore the Task stack pointer. */
     MOVW HL, AX
     MOVW AX, [ HL ]

portable/MPLAB/PIC32MZ/port.c

@@ -234,6 +234,11 @@ __attribute__(( weak )) void vApplicationSetupTickTimerInterrupt( void )
 {
 const uint32_t ulCompareMatch = ( (configPERIPHERAL_CLOCK_HZ / portTIMER_PRESCALE) / configTICK_RATE_HZ ) - 1UL;
 
+    /* PR1 is 16-bit. Ensure that the configPERIPHERAL_CLOCK_HZ and
+     * configTICK_RATE_HZ are defined such that ulCompareMatch value would fit
+     * in 16-bits. */
+    configASSERT( ( ulCompareMatch & 0xFFFF0000 ) == 0 );
+
     T1CON = 0x0000;
     T1CONbits.TCKPS = portPRESCALE_BITS;
     PR1 = ulCompareMatch;

portable/MSVC-MingW/port.c

@@ -33,6 +33,14 @@
 #include "FreeRTOS.h"
 #include "task.h"
 
+#ifdef WIN32_LEAN_AND_MEAN
+    #include <winsock2.h>
+#else
+    #include <winsock.h>
+#endif
+
+#include <timeapi.h>
+
 #ifdef __GNUC__
     #include "mmsystem.h"
 #else
@@ -144,6 +152,7 @@ static DWORD WINAPI prvSimulatedPeripheralTimer( LPVOID lpParameter )
     TickType_t xWaitTimeBetweenTicks = portTICK_PERIOD_MS;
     HANDLE hTimer = NULL;
     LARGE_INTEGER liDueTime;
+    BOOL bSuccess;
 
     /* Set the timer resolution to the maximum possible. */
     if( timeGetDevCaps( &xTimeCaps, sizeof( xTimeCaps ) ) == MMSYSERR_NOERROR )
@@ -182,7 +191,8 @@ static DWORD WINAPI prvSimulatedPeripheralTimer( LPVOID lpParameter )
 
     /* Set the Waitable Timer. The timer is set to run periodically at every
     xWaitTimeBetweenTicks milliseconds. */
-    configASSERT( SetWaitableTimer( hTimer, &liDueTime, xWaitTimeBetweenTicks, NULL, NULL, 0 ) );
+    bSuccess = SetWaitableTimer( hTimer, &liDueTime, xWaitTimeBetweenTicks, NULL, NULL, 0 );
+    configASSERT( bSuccess );
 
     while( xPortRunning == pdTRUE )
     {

portable/MSVC-MingW/portmacro.h

@@ -29,17 +29,6 @@
 #ifndef PORTMACRO_H
 #define PORTMACRO_H
 
-#ifdef WIN32_LEAN_AND_MEAN
-    #include <winsock2.h>
-#else
-    #include <winsock.h>
-#endif
-
-#include <windows.h>
-#include <timeapi.h>
-#include <mmsystem.h>
-#include <winbase.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -156,22 +145,25 @@ void vPortExitCritical( void );
                          : "cc" )
 
     #else /* __GNUC__ */
+        #include <intrin.h>
 
         /* BitScanReverse returns the bit position of the most significant '1'
          * in the word. */
         #if defined( __x86_64__ ) || defined( _M_X64 )
+            #pragma intrinsic(_BitScanReverse64)
 
             #define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities )    \
             do                                                                      \
             {                                                                       \
-                DWORD ulTopPriority;                                                \
+                unsigned long ulTopPriority;                                        \
                 _BitScanReverse64( &ulTopPriority, ( uxReadyPriorities ) );         \
                 uxTopPriority = ulTopPriority;                                      \
             } while( 0 )
 
         #else /* #if defined( __x86_64__ ) || defined( _M_X64 ) */
+            #pragma intrinsic(_BitScanReverse)
 
-            #define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities )    _BitScanReverse( ( DWORD * ) &( uxTopPriority ), ( uxReadyPriorities ) )
+            #define portGET_HIGHEST_PRIORITY( uxTopPriority, uxReadyPriorities )    _BitScanReverse( ( unsigned long * ) &( uxTopPriority ), ( uxReadyPriorities ) )
 
         #endif /* #if defined( __x86_64__ ) || defined( _M_X64 ) */
 

portable/MemMang/heap_4.c

@@ -572,7 +572,7 @@ static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert ) /* PRIVI
 void vPortGetHeapStats( HeapStats_t * pxHeapStats )
 {
     BlockLink_t * pxBlock;
-    size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY used as a portable way of getting the maximum value. */
+    size_t xBlocks = 0, xMaxSize = 0, xMinSize = SIZE_MAX;
 
     vTaskSuspendAll();
     {

portable/MemMang/heap_5.c

@@ -672,7 +672,7 @@ void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions ) /* PRIVI
 void vPortGetHeapStats( HeapStats_t * pxHeapStats )
 {
     BlockLink_t * pxBlock;
-    size_t xBlocks = 0, xMaxSize = 0, xMinSize = portMAX_DELAY; /* portMAX_DELAY used as a portable way of getting the maximum value. */
+    size_t xBlocks = 0, xMaxSize = 0, xMinSize = SIZE_MAX;
 
     vTaskSuspendAll();
     {

portable/RVDS/ARM_CM4_MPU/port.c

@@ -1,6 +1,8 @@
 /*
  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * Copyright 2025 Arm Limited and/or its affiliates
+ * <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: MIT
  *
@@ -474,7 +476,7 @@ void vSVCHandler_C( uint32_t * pulParam )
         extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulSystemCallStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i, r1;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i, r1;
         extern uint32_t __syscalls_flash_start__;
         extern uint32_t __syscalls_flash_end__;
 
@@ -500,23 +502,27 @@ void vSVCHandler_C( uint32_t * pulParam )
         {
             pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
             {
                 /* Extended frame i.e. FPU in use. */
-                ulStackFrameSize = 26;
+                ulHardwareSavedExceptionFrameSize = 26;
                 prvTriggerLazyStacking();
             }
             else
             {
                 /* Standard frame i.e. FPU not in use. */
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
 
             /* Make space on the system call stack for the stack frame. */
-            pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
+            pulSystemCallStack = pulSystemCallStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulSystemCallStack[ i ] = pulTaskStack[ i ];
             }
@@ -537,7 +543,7 @@ void vSVCHandler_C( uint32_t * pulParam )
 
             /* Remember the location where we should copy the stack frame when we exit from
              * the system call. */
-            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
+            pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulHardwareSavedExceptionFrameSize;
 
             /* Store the value of the Link Register before the SVC was raised.
              * It contains the address of the caller of the System Call entry
@@ -592,7 +598,7 @@ void vSVCHandler_C( uint32_t * pulParam )
         extern TaskHandle_t pxCurrentTCB;
         xMPU_SETTINGS * pxMpuSettings;
         uint32_t * pulTaskStack;
-        uint32_t ulStackFrameSize, ulSystemCallLocation, i, r1;
+        uint32_t ulHardwareSavedExceptionFrameSize, ulSystemCallLocation, i, r1;
         extern uint32_t __privileged_functions_start__;
         extern uint32_t __privileged_functions_end__;
 
@@ -614,23 +620,27 @@ void vSVCHandler_C( uint32_t * pulParam )
         {
             pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
 
+            /* Hardware Saved Stack Frame Size upon Exception entry:
+             * - No FPU: basic frame (R0-R3, R12, LR, PC, and xPSR) = 8 words.
+             * - With FPU (lazy stacking): basic frame + S0–S15 + FPSCR + reserved word = 26 words.
+             */
             if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
             {
                 /* Extended frame i.e. FPU in use. */
-                ulStackFrameSize = 26;
+                ulHardwareSavedExceptionFrameSize = 26;
                 prvTriggerLazyStacking();
             }
             else
             {
                 /* Standard frame i.e. FPU not in use. */
-                ulStackFrameSize = 8;
+                ulHardwareSavedExceptionFrameSize = 8;
             }
 
             /* Make space on the task stack for the stack frame. */
-            pulTaskStack = pulTaskStack - ulStackFrameSize;
+            pulTaskStack = pulTaskStack - ulHardwareSavedExceptionFrameSize;
 
             /* Copy the stack frame. */
-            for( i = 0; i < ulStackFrameSize; i++ )
+            for( i = 0; i < ulHardwareSavedExceptionFrameSize; i++ )
             {
                 pulTaskStack[ i ] = pulSystemCallStack[ i ];
             }

portable/ThirdParty/GCC/ARM_TFM/README.md

@@ -52,13 +52,13 @@ Kernel runs in the Non-Secure Side.
 The setting of this macro is decided by the setting in Secure Side which is platform-specific.
 If the Secure Side enables Non-Secure access to FPU, then this macro can be configured as 0 or 1. Otherwise, this macro can only be configured as 0.
 Please note that Cortex-M23 does not support FPU.
-Please refer to [TF-M documentation](https://tf-m-user-guide.trustedfirmware.org/integration_guide/tfm_fpu_support.html) for FPU usage on the Non-Secure side.
+Please refer to [TF-M documentation](https://trustedfirmware-m.readthedocs.io/en/latest/integration_guide/tfm_fpu_support.html) for FPU usage on the Non-Secure side.
 
 * `configENABLE_MVE`
 The setting of this macro is decided by the setting in Secure Side which is platform-specific.
 If the Secure Side enables Non-Secure access to MVE, then this macro can be configured as 0 or 1. Otherwise, this macro can only be configured as 0.
 Please note that only Cortex-M55 and Cortex-M85 support MVE.
-Please refer to [TF-M documentation](https://tf-m-user-guide.trustedfirmware.org/integration_guide/tfm_fpu_support.html) for MVE usage on the Non-Secure side.
+Please refer to [TF-M documentation](https://trustedfirmware-m.readthedocs.io/en/latest/integration_guide/tfm_fpu_support.html) for MVE usage on the Non-Secure side.
 
 * `configENABLE_TRUSTZONE`
 This macro should be configured as 0 because TF-M doesn't use the secure context management function of FreeRTOS. New secure context management might be introduced when TF-M supports multiple secure context.

portable/ThirdParty/GCC/Posix/port.c

@@ -140,6 +140,8 @@ static void prvThreadKeyDestructor( void * pvData )
 static void prvInitThreadKey( void )
 {
     pthread_key_create( &xThreadKey, prvThreadKeyDestructor );
+    /* Destroy xThreadKey when the process exits. */
+    atexit( prvDestroyThreadKey );
 }
 /*-----------------------------------------------------------*/
 
@@ -193,7 +195,7 @@ void prvFatalError( const char * pcCall,
 }
 /*-----------------------------------------------------------*/
 
-static void prvPortSetCurrentThreadName( char * pxThreadName )
+static void prvPortSetCurrentThreadName( const char * pxThreadName )
 {
     #ifdef __APPLE__
         pthread_setname_np( pxThreadName );
@@ -227,6 +229,7 @@ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
     /* Ensure that there is enough space to store Thread_t on the stack. */
     ulStackSize = ( size_t ) ( pxTopOfStack + 1 - pxEndOfStack ) * sizeof( *pxTopOfStack );
     configASSERT( ulStackSize > sizeof( Thread_t ) );
+    ( void ) ulStackSize; /* suppress set but not used warning */
 
     thread->pxCode = pxCode;
     thread->pvParams = pvParameters;
@@ -315,8 +318,6 @@ BaseType_t xPortStartScheduler( void )
     /* Restore original signal mask. */
     ( void ) pthread_sigmask( SIG_SETMASK, &xSchedulerOriginalSignalMask, NULL );
 
-    prvDestroyThreadKey();
-
     return 0;
 }
 /*-----------------------------------------------------------*/
@@ -324,17 +325,23 @@ BaseType_t xPortStartScheduler( void )
 void vPortEndScheduler( void )
 {
     Thread_t * pxCurrentThread;
+    BaseType_t xIsFreeRTOSThread;
 
     /* Stop the timer tick thread. */
     xTimerTickThreadShouldRun = false;
     pthread_join( hTimerTickThread, NULL );
 
+    /* Check whether the current thread is a FreeRTOS thread.
+     * This has to happen before the scheduler is signaled to exit
+     * its loop to prevent data races on the thread key. */
+    xIsFreeRTOSThread = prvIsFreeRTOSThread();
+
     /* Signal the scheduler to exit its loop. */
     xSchedulerEnd = pdTRUE;
     ( void ) pthread_kill( hMainThread, SIG_RESUME );
 
     /* Waiting to be deleted here. */
-    if( prvIsFreeRTOSThread() == pdTRUE )
+    if( xIsFreeRTOSThread == pdTRUE )
     {
         pxCurrentThread = prvGetThreadFromTask( xTaskGetCurrentTaskHandle() );
         event_wait( pxCurrentThread->ev );

portable/ThirdParty/GCC/RP2040/include/portmacro.h

@@ -227,7 +227,7 @@ static inline void vPortRecursiveLock( BaseType_t xCoreID,
             if( ucOwnedByCore[ xCoreID ][ ulLockNum ] )
             {
                 configASSERT( ucRecursionCountByLock[ ulLockNum ] != 255u );
-                ucRecursionCountByLock[ ulLockNum ]++;
+                ucRecursionCountByLock[ ulLockNum ] = ucRecursionCountByLock[ ulLockNum ] + 1;
                 return;
             }
             spin_lock_unsafe_blocking(pxSpinLock);
@@ -241,7 +241,8 @@ static inline void vPortRecursiveLock( BaseType_t xCoreID,
         configASSERT( ( ucOwnedByCore[ xCoreID ] [ulLockNum ] ) != 0 );
         configASSERT( ucRecursionCountByLock[ ulLockNum ] != 0 );
 
-        if( !--ucRecursionCountByLock[ ulLockNum ] )
+        ucRecursionCountByLock[ ulLockNum ] = ucRecursionCountByLock[ ulLockNum ] - 1;
+        if ( ucRecursionCountByLock[ ulLockNum ] == 0U )
         {
             ucOwnedByCore[ xCoreID ] [ ulLockNum ] = 0;
             spin_unlock_unsafe(pxSpinLock);

queue.c

@@ -833,6 +833,10 @@ static void prvInitialiseNewQueue( const UBaseType_t uxQueueLength,
         if( pxMutex->u.xSemaphore.xMutexHolder == xTaskGetCurrentTaskHandle() )
         {
             ( pxMutex->u.xSemaphore.uxRecursiveCallCount )++;
+
+            /* Check if an overflow occurred. */
+            configASSERT( pxMutex->u.xSemaphore.uxRecursiveCallCount );
+
             xReturn = pdPASS;
         }
         else
@@ -845,6 +849,9 @@ static void prvInitialiseNewQueue( const UBaseType_t uxQueueLength,
             if( xReturn != pdFAIL )
             {
                 ( pxMutex->u.xSemaphore.uxRecursiveCallCount )++;
+
+                /* Check if an overflow occurred. */
+                configASSERT( pxMutex->u.xSemaphore.uxRecursiveCallCount );
             }
             else
             {
@@ -1168,9 +1175,8 @@ BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue,
 
     traceENTER_xQueueGenericSendFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken, xCopyPosition );
 
-    configASSERT( pxQueue );
+    configASSERT( ( pxQueue != NULL ) && !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
-    configASSERT( !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
+    configASSERT( ( pxQueue != NULL ) && !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) );
-    configASSERT( !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) );
 
     /* RTOS ports that support interrupt nesting have the concept of a maximum
      * system call (or maximum API call) interrupt priority.  Interrupts that are
@@ -1344,16 +1350,14 @@ BaseType_t xQueueGiveFromISR( QueueHandle_t xQueue,
      * not (i.e. has a task with a higher priority than us been woken by this
      * post). */
 
-    configASSERT( pxQueue );
-
     /* xQueueGenericSendFromISR() should be used instead of xQueueGiveFromISR()
      * if the item size is not 0. */
-    configASSERT( pxQueue->uxItemSize == 0 );
+    configASSERT( ( pxQueue != NULL ) && ( pxQueue->uxItemSize == 0 ) );
 
     /* Normally a mutex would not be given from an interrupt, especially if
      * there is a mutex holder, as priority inheritance makes no sense for an
-     * interrupts, only tasks. */
+     * interrupt, only tasks. */
-    configASSERT( !( ( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX ) && ( pxQueue->u.xSemaphore.xMutexHolder != NULL ) ) );
+    configASSERT( ( pxQueue != NULL ) && !( ( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX ) && ( pxQueue->u.xSemaphore.xMutexHolder != NULL ) ) );
 
     /* RTOS ports that support interrupt nesting have the concept of a maximum
      * system call (or maximum API call) interrupt priority.  Interrupts that are
@@ -1888,12 +1892,9 @@ BaseType_t xQueuePeek( QueueHandle_t xQueue,
 
     traceENTER_xQueuePeek( xQueue, pvBuffer, xTicksToWait );
 
-    /* Check the pointer is not NULL. */
-    configASSERT( ( pxQueue ) );
-
     /* The buffer into which data is received can only be NULL if the data size
      * is zero (so no data is copied into the buffer. */
-    configASSERT( !( ( ( pvBuffer ) == NULL ) && ( ( pxQueue )->uxItemSize != ( UBaseType_t ) 0U ) ) );
+    configASSERT( ( pxQueue != NULL ) && !( ( ( pvBuffer ) == NULL ) && ( ( pxQueue )->uxItemSize != ( UBaseType_t ) 0U ) ) );
 
     /* Cannot block if the scheduler is suspended. */
     #if ( ( INCLUDE_xTaskGetSchedulerState == 1 ) || ( configUSE_TIMERS == 1 ) )
@@ -2145,9 +2146,8 @@ BaseType_t xQueuePeekFromISR( QueueHandle_t xQueue,
 
     traceENTER_xQueuePeekFromISR( xQueue, pvBuffer );
 
-    configASSERT( pxQueue );
+    configASSERT( ( pxQueue != NULL ) && !( ( pvBuffer == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
-    configASSERT( !( ( pvBuffer == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
+    configASSERT( ( pxQueue != NULL ) && ( pxQueue->uxItemSize != 0 ) ); /* Can't peek a semaphore. */
-    configASSERT( pxQueue->uxItemSize != 0 ); /* Can't peek a semaphore. */
 
     /* RTOS ports that support interrupt nesting have the concept of a maximum
      * system call (or maximum API call) interrupt priority.  Interrupts that are

stream_buffer.c

@@ -1653,11 +1653,9 @@ void vStreamBufferSetStreamBufferNotificationIndex( StreamBufferHandle_t xStream
 
     traceENTER_vStreamBufferSetStreamBufferNotificationIndex( xStreamBuffer, uxNotificationIndex );
 
-    configASSERT( pxStreamBuffer );
-
     /* There should be no task waiting otherwise we'd never resume them. */
-    configASSERT( pxStreamBuffer->xTaskWaitingToReceive == NULL );
+    configASSERT( ( pxStreamBuffer != NULL ) && ( pxStreamBuffer->xTaskWaitingToReceive == NULL ) );
-    configASSERT( pxStreamBuffer->xTaskWaitingToSend == NULL );
+    configASSERT( ( pxStreamBuffer != NULL ) && ( pxStreamBuffer->xTaskWaitingToSend == NULL ) );
 
     /* Check that the task notification index is valid. */
     configASSERT( uxNotificationIndex < configTASK_NOTIFICATION_ARRAY_ENTRIES );

tasks.c

@@ -893,7 +893,7 @@ static void prvAddNewTaskToReadyList( TCB_t * pxNewTCB ) PRIVILEGED_FUNCTION;
         BaseType_t xCurrentCoreTaskPriority;
         BaseType_t xLowestPriorityCore = ( BaseType_t ) -1;
         BaseType_t xCoreID;
-        const BaseType_t xCurrentCoreID = portGET_CORE_ID();
+        const BaseType_t xCurrentCoreID = ( BaseType_t ) portGET_CORE_ID();
 
         #if ( configRUN_MULTIPLE_PRIORITIES == 0 )
             BaseType_t xYieldCount = 0;