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FreeRTOS-Kernel/portable/GCC/ARM_CRx_MPU/port.c

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/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/* Standard includes. */
#include <stdint.h>
/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
* all the API functions to use the MPU wrappers. That should only be done when
* task.h is included from an application file. */
#ifndef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
#endif /* MPU_WRAPPERS_INCLUDED_FROM_API_FILE */
/* Scheduler includes. */
#include "FreeRTOSConfig.h"
#include "FreeRTOS.h"
#include "portmacro_asm.h"
#include "portmacro.h"
#include "task.h"
#include "mpu_syscall_numbers.h"
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
/** @brief Variable used to keep track of critical section nesting.
* @ingroup Critical Sections
* @note
* This variable has to be stored as part of the task context and must be
* initialised to a non zero value to ensure interrupts don't inadvertently
* become unmasked before the scheduler starts. As it is stored as part of the
* task context it will be set to 0 when the first task is started.
*/
PRIVILEGED_DATA volatile uint32_t ulCriticalNesting = 0xFFFF;
/** @brief Set to 1 to pend a context switch from an ISR.
* @ingroup Interrupt Management
*/
PRIVILEGED_DATA volatile uint32_t ulPortYieldRequired = pdFALSE;
/** @brief Interrupt nesting depth, used to count the number of interrupts to unwind.
* @ingroup Interrupt Management
*/
PRIVILEGED_DATA volatile uint32_t ulPortInterruptNesting = 0UL;
/** @brief Variable to track whether or not the scheduler has been started.
* @ingroup Scheduler
* @note This variable is set to pdTRUE when the scheduler is started.
*/
PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
/** @brief Used in portASM.S's IRQ Handler to clear an interrupt.
* @ingroup Interrupt Management
*/
PRIVILEGED_DATA volatile uint32_t ulICCEOIR = configEOI_ADDRESS;
/*---------------------------------------------------------------------------*/
/** @brief Set a FreeRTOS Task's initial context
*
* @param pxTopOfStack Pointer to where the task's stack starts
* @param pxCode Pointer to the function a task will run
* @param pvParameters Pointer to any arguments to be passed to the task's function
* @param xRunPrivileged Marks if the task is to be run in a privileged CPU mode.
* @param xMPUSettings MPU settings to be loaded as part of a task's context
* @return StackType_t* Pointer to where to restore the task's context from.
*
* @ingroup Task Context
* @note pxTopOfStack must be a region of memory that is a valid MPU region size.
*/
/* PRIVILEGED_FUNCTION */ StackType_t * pxPortInitialiseStack(
StackType_t * pxTopOfStack,
TaskFunction_t pxCode,
void * pvParameters,
BaseType_t xRunPrivileged,
xMPU_SETTINGS * xMPUSettings
)
{
/** Setup the initial context of the task. The context is set exactly as
* expected by the portRESTORE_CONTEXT() macro. */
UBaseType_t ulContextIndex = MAX_CONTEXT_SIZE - 1U;
if( xRunPrivileged == pdTRUE )
{
/* Current Program Status and Control Register */
xMPUSettings->ulTaskFlags |= portTASK_IS_PRIVILEGED_FLAG;
xMPUSettings->ulTaskFlags |= 0x1F000000;
xMPUSettings->ulContext[ ulContextIndex ] = SYS_MODE;
}
else
{
/* Current Program Status and Control Register */
xMPUSettings->ulTaskFlags &= ( ~portTASK_IS_PRIVILEGED_FLAG );
xMPUSettings->ulTaskFlags |= 0x10000000;
xMPUSettings->ulContext[ ulContextIndex ] = USER_MODE;
}
if( ( ( uint32_t ) pxCode & portTHUMB_MODE_ADDRESS ) != 0x00UL )
{
/* The task will start in THUMB mode, set the bit in the CPSR. */
xMPUSettings->ulContext[ ulContextIndex ] |= portTHUMB_MODE_BIT;
xMPUSettings->ulTaskFlags |= portSTACK_FRAME_HAS_PADDING_FLAG;
}
/* Decrement ulContextIndex here after setting the CPSR */
ulContextIndex--;
/** First we load the Memory Location of the Task's function.
* Task Program Counter */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) pxCode;
/** A FreeRTOS Task is not designed to return or exit from its function.
* As such a default Link Register is provided that will return to an
* error handling function.
* Task Link Register */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) portTASK_RETURN_ADDRESS;
/** Set the task's stack pointer to be the bottom of it's stack, since on this
* CPU stacks grow upwards.
* Task Stack Pointer */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) pxTopOfStack; /* SP */
/* Next the General Purpose Registers */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x12121212; /* R12 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x11111111; /* R11 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x10101010; /* R10 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x09090909; /* R9 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x08080808; /* R8 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x07070707; /* R7 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x06060606; /* R6 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x05050505; /* R5 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x04040404; /* R4 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x03030303; /* R3 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x02020202; /* R2 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x01010101; /* R1 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) pvParameters; /* R0 */
#ifdef portENABLE_FPU
/* Initial Floating Point Context is the Floating Point Registers (FPRs) */
/* There are 16 Double FPRs, D0-D15 on the Cortex-R FPU enabled chips */
/* These map to the Single Precision FPRs, S0-S31 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000015; /* S31 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1500000; /* S30 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000014; /* S29 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1400000; /* S28 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000013; /* S27 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1300000; /* S26 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000012; /* S25 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1200000; /* S24 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000011; /* S23 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1100000; /* S22 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000010; /* S21 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1000000; /* S20 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000009; /* S19 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD9000000; /* S18 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000008; /* S17 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD8000000; /* S16 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000007; /* S15 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD7000000; /* S14 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000006; /* S13 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD6000000; /* S12 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000005; /* S11 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD5000000; /* S10 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000004; /* S9 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD4000000; /* S8 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000003; /* S7 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD3000000; /* S6 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000002; /* S5 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD2000000; /* S4 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000001; /* S3 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD1000000; /* S2 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000000; /* S1 */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0xD0000000; /* S0 */
/* Floating Point Status and Control Register */
xMPUSettings->ulContext[ ulContextIndex-- ] = ( StackType_t ) 0x00000000; /* FPSR */
#endif /* portENABLE_FPU */
/* The task will start with a critical nesting count of 0. */
xMPUSettings->ulContext[ ulContextIndex ] = portNO_CRITICAL_NESTING;
/* Ensure that the system call stack is double word aligned. */
xSYSTEM_CALL_STACK_INFO * xSysCallInfo = &( xMPUSettings->xSystemCallStackInfo );
xSysCallInfo->pulSystemCallStackPointer = &(
xSysCallInfo->ulSystemCallStackBuffer[ configSYSTEM_CALL_STACK_SIZE - 1U ]
);
xSysCallInfo->pulSystemCallStackPointer =
( uint32_t * ) ( ( uint32_t ) ( xSysCallInfo->pulSystemCallStackPointer ) & ( uint32_t ) ( ~( portBYTE_ALIGNMENT_MASK ) ) );
/* This is not NULL only for the duration of a system call. */
xSysCallInfo->pulTaskStackPointer = NULL;
/* Set the System Call LR to go directly to vPortSystemCallExit */
xSysCallInfo->pulSystemCallLinkRegister = &vPortSystemCallExit;
/* Return the address where the context of this task should be restored from */
return ( &xMPUSettings->ulContext[ ulContextIndex ] );
}
/*----------------------------------------------------------------------------*/
/** @brief Returns the smallest valid MPU Region size that can hold a number of bytes.
*
* @ingroup MPU Control
*
* @param ulActualSizeInBytes Number of bytes to find a valid MPU region size for
* @return uint32_t The smallest MPU region size that can hold the requested bytes.
*/
PRIVILEGED_FUNCTION static uint32_t prvGetMPURegionSizeSetting(
uint32_t ulActualSizeInBytes
);
/* PRIVILEGED_FUNCTION */ static uint32_t prvGetMPURegionSizeSetting(
uint32_t ulActualSizeInBytes
)
{
uint32_t ulRegionSize, ulReturnValue = 4U;
/* 32 is the smallest region size, 31 is the largest valid value for
* ulReturnValue. */
for( ulRegionSize = 32UL; ulReturnValue < 31UL; ( ulRegionSize <<= 1UL ) )
{
if( ulActualSizeInBytes <= ulRegionSize )
{
break;
}
else
{
ulReturnValue++;
}
}
/* Shift the code by one before returning so it can be written directly
* into the the correct bit position of the attribute register. */
return ulReturnValue << 1UL;
}
/*----------------------------------------------------------------------------*/
/** @brief Stores a FreeRTOS Task's MPU Settings in its TCB
*
* @param xMPUSettings The memory location in the TCB to store MPU settings
* @param xRegions The MPU settings being requested by the task.
* @param pxBottomOfStack The base address of the Task's Stack
* @param ulStackDepth The length of the task's stack.
*
* @ingroup Task Context
* @ingroup MPU Control
*
* @note pxBottomOfStack must be aligned to a region size of length ulStackDepth.
* @note ulStackDepth must be a power of 2 larger than 32 bytes.
*/
/* PRIVILEGED_FUNCTION */ void vPortStoreTaskMPUSettings(
xMPU_SETTINGS * xMPUSettings,
const struct xMEMORY_REGION * const xRegions,
StackType_t * pxBottomOfStack,
uint32_t ulStackDepth
)
{
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
* exported from linker scripts. */
extern uint32_t * __SRAM_segment_start__;
extern uint32_t * __SRAM_segment_end__;
extern uint32_t * __privileged_data_start__;
extern uint32_t * __privileged_data_end__;
#else
/* Declaration when these variable are exported from linker scripts. */
extern uint32_t __SRAM_segment_start__[];
extern uint32_t __SRAM_segment_end__[];
#endif /* if defined( __ARMCC_VERSION ) */
uint32_t lIndex = 0x0;
uint32_t ul = 0x0;
if( xRegions == NULL )
{
/* No MPU regions are specified so allow access to all of the RAM. */
xMPUSettings->xRegion[ 0 ].ulRegionBaseAddress = ( uint32_t
) __SRAM_segment_start__;
xMPUSettings->xRegion[ 0 ].ulRegionSize = ( prvGetMPURegionSizeSetting(
( uint32_t ) __SRAM_segment_end__ -
( uint32_t ) __SRAM_segment_start__
) ) |
portMPU_REGION_ENABLE;
xMPUSettings->xRegion[ 0 ].ulRegionAttribute = portMPU_PRIV_RW_USER_RW_NOEXEC |
portMPU_NORMAL_OIWTNOWA_SHARED;
/* Invalidate all other regions. */
for( ul = 1; ul <= portNUM_CONFIGURABLE_REGIONS; ul++ )
{
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress = 0x0UL;
xMPUSettings->xRegion[ ul ].ulRegionSize = 0x0UL;
xMPUSettings->xRegion[ ul ].ulRegionAttribute = 0x0UL;
}
}
else
{
/* This function is called automatically when the task is created - in
* which case the stack region parameters will be valid. At all other
* times the stack parameters will not be valid and it is assumed that the
* stack region has already been configured. */
if( ulStackDepth > 0 )
{
uint32_t ulSmallestRegion = prvGetMPURegionSizeSetting( ulStackDepth * 0x4 );
/* Define the region that allows access to the stack. */
xMPUSettings->xRegion[ 0 ].ulRegionBaseAddress = ( uint32_t ) pxBottomOfStack;
xMPUSettings->xRegion[ 0 ].ulRegionSize = ulSmallestRegion |
portMPU_REGION_ENABLE;
xMPUSettings->xRegion[ 0 ].ulRegionAttribute = portMPU_PRIV_RW_USER_RW_NOEXEC |
portMPU_NORMAL_OIWTNOWA_SHARED;
}
for( ul = 1; ul <= portNUM_CONFIGURABLE_REGIONS; ul++ )
{
if( ( xRegions[ lIndex ] ).ulLengthInBytes > 0UL )
{
/* Translate the generic region definition contained in
* xRegions into the R4 specific MPU settings that are then
* stored in xMPUSettings. */
xMPUSettings->xRegion[ ul ]
.ulRegionBaseAddress = ( uint32_t ) xRegions[ lIndex ].pvBaseAddress;
xMPUSettings->xRegion[ ul ]
.ulRegionSize = prvGetMPURegionSizeSetting(
xRegions[ lIndex ].ulLengthInBytes
) |
portMPU_REGION_ENABLE;
xMPUSettings->xRegion[ ul ].ulRegionAttribute = xRegions[ lIndex ]
.ulParameters;
}
else
{
/* Invalidate the region. */
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress = 0x0UL;
xMPUSettings->xRegion[ ul ].ulRegionSize = 0x0UL;
xMPUSettings->xRegion[ ul ].ulRegionAttribute = 0x0UL;
}
lIndex++;
}
}
}
/*----------------------------------------------------------------------------*/
/** @brief Set up a default MPU memory Map
* @return PRIVILEGED_FUNCTION VOID
* @ingroup MPU Control
* @note This function shall be called before calling vPortStartFirstTask().
* @note This function works by pulling variables from the linker script.
* Ensure that the variables used in your linker script match up with the variable names
* used at the start of this function.
*/
PRIVILEGED_FUNCTION static void prvSetupDefaultMPU( void )
{
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
* exported from linker scripts. */
/* Sections used for FLASH */
extern uint32_t * __FLASH_segment_start__;
extern uint32_t * __FLASH_segment_end__;
extern uint32_t * __privileged_functions_start__;
extern uint32_t * __privileged_functions_end__;
/* Sections used for RAM */
extern uint32_t * __SRAM_segment_start__;
extern uint32_t * __SRAM_segment_end__;
extern uint32_t * __privileged_data_start__;
extern uint32_t * __privileged_data_end__;
/* Sections used for system peripherals, such as UART */
extern uint32_t * __peripherals_start__;
extern uint32_t * __peripherals_end__;
#else
/* Declaration when these variable are exported from linker scripts. */
/* Sections used for FLASH */
extern uint32_t __FLASH_segment_start__[];
extern uint32_t __FLASH_segment_end__[];
extern uint32_t __privileged_functions_start__[];
extern uint32_t __privileged_functions_end__[];
/* Sections used for RAM */
extern uint32_t __SRAM_segment_start__[];
extern uint32_t __SRAM_segment_end__[];
extern uint32_t __privileged_data_start__[];
extern uint32_t __privileged_data_end__[];
/* Sections used for system peripherals, such as UART */
extern uint32_t __peripherals_start__[];
extern uint32_t __peripherals_end__[];
#endif /* if defined( __ARMCC_VERSION ) */
uint32_t ulRegionStart;
uint32_t ulRegionEnd;
uint32_t ulRegionLength;
/* Ensure the MPU is disabled */
prvMpuDisable();
/* Unprivileged and Privileged Read and Exec MPU Region for Flash */
ulRegionStart = ( uint32_t ) __FLASH_segment_start__;
ulRegionEnd = ( uint32_t ) __FLASH_segment_end__;
ulRegionLength = ulRegionEnd - ulRegionStart;
ulRegionLength = prvGetMPURegionSizeSetting( ulRegionLength ) | portMPU_REGION_ENABLE;
prvMpuSetRegion(
portUNPRIVILEGED_FLASH_REGION,
ulRegionStart,
ulRegionLength,
portMPU_PRIV_RO_USER_RO_EXEC | portMPU_NORMAL_OIWTNOWA_SHARED
);
/* Privileged Read and Exec MPU Region for PRIVILEGED_FUNCTIONS. */
ulRegionStart = ( uint32_t ) __privileged_functions_start__;
ulRegionEnd = ( uint32_t ) __privileged_functions_end__;
ulRegionLength = ulRegionEnd - ulRegionStart;
ulRegionLength = prvGetMPURegionSizeSetting( ulRegionLength ) | portMPU_REGION_ENABLE;
prvMpuSetRegion(
portPRIVILEGED_FLASH_REGION,
ulRegionStart,
ulRegionLength,
portMPU_PRIV_RO_USER_NA_EXEC | portMPU_NORMAL_OIWTNOWA_SHARED
);
/* MPU Region for Peripheral Usage */
ulRegionStart = ( uint32_t ) __peripherals_start__;
ulRegionEnd = ( uint32_t ) __peripherals_end__;
ulRegionLength = ulRegionEnd - ulRegionStart;
ulRegionLength = prvGetMPURegionSizeSetting( ulRegionLength ) | portMPU_REGION_ENABLE;
prvMpuSetRegion(
portGENERAL_PERIPHERALS_REGION,
ulRegionStart,
ulRegionLength,
portMPU_PRIV_RW_USER_RW_NOEXEC | portMPU_DEVICE_NONSHAREABLE
);
/* All Read, and Privileged Write MPU Region for PRIVILEGED_DATA. */
ulRegionStart = ( uint32_t ) __privileged_data_start__;
ulRegionEnd = ( uint32_t ) __privileged_data_end__;
ulRegionLength = ulRegionEnd - ulRegionStart;
ulRegionLength = prvGetMPURegionSizeSetting( ulRegionLength ) | portMPU_REGION_ENABLE;
prvMpuSetRegion(
portPRIVILEGED_RAM_REGION,
ulRegionStart,
ulRegionLength,
portMPU_PRIV_RW_USER_RO_NOEXEC | portMPU_NORMAL_OIWTNOWA_SHARED
);
/* After setting default regions, enable the MPU */
prvMpuEnable();
}
/* ------------------------------------------------------------------------- */
/** @brief Determine if a FreeRTOS Task has been granted access to a memory region
*
* @param xTaskMPURegion Pointer to a single set of MPU region registers.
* @param ulRegionStart Base address of the memory region access is being requested.
* @param ulRegionLength The length of the memory region that access is being requested.
* @param ulAccessRequested The type of access being requested, either read or write.
* @return BaseType_t pdTRUE if the task can access the region, pdFALSE otherwise
*
* @ingroup Task Context
* @ingroup MPU Control
*/
PRIVILEGED_FUNCTION static BaseType_t prvTaskCanAccessRegion(
const xMPU_REGION_REGISTERS * xTaskMPURegion,
const uint32_t ulRegionStart,
const uint32_t ulRegionLength,
const uint32_t ulAccessRequested
)
{
BaseType_t xAccessGranted;
uint32_t ulRegionEnd = ulRegionStart + ulRegionLength;
/* Convert the MPU Region Size value to the actual size */
uint32_t ulTaskRegionLength = 1 << ( ( xTaskMPURegion->ulRegionSize >> 1 ) + 1U );
// uint32_t ulTaskRegionLength = 2 << ( xTaskMPURegion->ulRegionSize >> 1 );
uint32_t ulTaskRegionEnd = xTaskMPURegion->ulRegionBaseAddress + ulTaskRegionLength;
if( ( ulRegionStart >= xTaskMPURegion->ulRegionBaseAddress ) &&
( ulRegionEnd <= ulTaskRegionEnd ) )
{
/* Unprivileged read is MPU Ctrl Access Bit Value bX1X */
if( ( tskMPU_READ_PERMISSION == ulAccessRequested ) &&
( ( portMPU_PRIV_RW_USER_RO_NOEXEC ) &xTaskMPURegion->ulRegionAttribute ) )
{
xAccessGranted = pdTRUE;
}
/* Unprivileged Write is MPU Ctrl Access Bit Value b011 */
else if( ( tskMPU_WRITE_PERMISSION & ulAccessRequested ) &&
( portMPU_PRIV_RW_USER_RW_NOEXEC ==
( portMPU_PRIV_RW_USER_RW_NOEXEC & xTaskMPURegion->ulRegionAttribute ) ) )
{
xAccessGranted = pdTRUE;
}
else
{
xAccessGranted = pdFALSE;
}
}
else
{
xAccessGranted = pdFALSE;
}
return xAccessGranted;
}
/* ------------------------------------------------------------------------- */
/* PRIVILEGED_FUNCTION */ BaseType_t xPortIsAuthorizedToAccessBuffer(
const void * pvBuffer,
uint32_t ulBufferLength,
uint32_t ulAccessRequested
)
{
BaseType_t xAccessGranted;
/* Calling task's MPU settings. */
xMPU_SETTINGS * xTaskMPUSettings = NULL;
xMPU_REGION_REGISTERS * xTaskMPURegion = NULL;
if( pdFALSE == xSchedulerRunning )
{
/* Before the scheduler starts an unknown task will be pxCurrentTCB */
xAccessGranted = pdTRUE;
}
else
{
xTaskMPUSettings = xTaskGetMPUSettings( NULL );
if( NULL == xTaskMPUSettings )
{
xAccessGranted = pdFALSE;
}
else if( xTaskMPUSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG )
{
/* If a task is privileged it is assumed that it can access the buffer */
xAccessGranted = pdTRUE;
}
else
{
uint32_t ulRegionIndex = 0x0UL;
do
{
xTaskMPURegion = &( xTaskMPUSettings->xRegion[ ulRegionIndex++ ] );
xAccessGranted = prvTaskCanAccessRegion(
xTaskMPURegion,
( uint32_t ) pvBuffer,
ulBufferLength,
ulAccessRequested
);
} while( ( pdFALSE == xAccessGranted ) &&
( ulRegionIndex < portTOTAL_NUM_REGIONS_IN_TCB ) );
}
}
return xAccessGranted;
}
/*---------------------------------------------------------------------------*/
/** @brief Determine if the FreeRTOS Task was created as a privileged task
*
* @ingroup MPU Control
* @ingroup Task Context
*
* @return pdTRUE if the Task was created as a privileged task.
* pdFALSE if the task was not created as a privileged task.
*
*/
/* PRIVILEGED_FUNCTION */ BaseType_t xPortIsTaskPrivileged( void )
{
BaseType_t xTaskIsPrivileged = pdFALSE;
/* Calling task's MPU settings. */
const xMPU_SETTINGS * xTaskMpuSettings = xTaskGetMPUSettings( NULL );
if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) ==
portTASK_IS_PRIVILEGED_FLAG )
{
xTaskIsPrivileged = pdTRUE;
}
return xTaskIsPrivileged;
}
/** @brief Start the FreeRTOS-Kernel's control of Tasks by starting the System Tick
* Interrupt.
*
* @ingroup Scheduler
* @return BaseType_t This function is not meant to be returned from.
* If it does return it returns pdFALSE to mark that the scheduler could not be started.
*/
BaseType_t xPortStartScheduler( void )
{
/* Start the timer that generates the tick ISR. */
configSETUP_TICK_INTERRUPT();
/* Reset the critical section nesting count read to execute the first task. */
ulCriticalNesting = 0UL;
/* Configure the regions in the MPU that are common to all tasks. */
prvSetupDefaultMPU();
xSchedulerRunning = pdTRUE;
/* Load the context of the first task, starting the FreeRTOS-Scheduler's control. */
vPortStartFirstTask();
/* Will only get here if vTaskStartScheduler() was called with the CPU in
* a non-privileged mode or the binary point register was not set to its lowest
* possible value. prvTaskExitError() is referenced to prevent a compiler
* warning about it being defined but not referenced in the case that the user
* defines their own exit address. */
( void ) prvTaskExitError();
return 0;
}
/*---------------------------------------------------------------------------*/
#if( configENABLE_ACCESS_CONTROL_LIST == 1 )
/* PRIVILEGED_FUNCTION */ BaseType_t xPortIsAuthorizedToAccessKernelObject(
int32_t lInternalIndexOfKernelObject
)
{
uint32_t ulAccessControlListEntryIndex, ulAccessControlListEntryBit;
BaseType_t xAccessGranted = pdFALSE;
const xMPU_SETTINGS * xTaskMpuSettings;
if( xSchedulerRunning == pdFALSE )
{
/* Grant access to all the kernel objects before the scheduler
* is started. It is necessary because there is no task running
* yet and therefore, we cannot use the permissions of any
* task. */
xAccessGranted = pdTRUE;
}
else
{
xTaskMpuSettings = xTaskGetMPUSettings( NULL ); /* Calling task's MPU settings. */
ulAccessControlListEntryIndex =
( ( uint32_t ) lInternalIndexOfKernelObject / portACL_ENTRY_SIZE_BITS );
ulAccessControlListEntryBit =
( ( uint32_t ) lInternalIndexOfKernelObject % portACL_ENTRY_SIZE_BITS );
if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) ==
portTASK_IS_PRIVILEGED_FLAG )
{
xAccessGranted = pdTRUE;
}
else
{
if( ( xTaskMpuSettings->ulAccessControlList[ ulAccessControlListEntryIndex ] &
( 1U << ulAccessControlListEntryBit ) ) != 0 )
{
xAccessGranted = pdTRUE;
}
}
}
return xAccessGranted;
}
/* PRIVILEGED_FUNCTION */ void vPortGrantAccessToKernelObject(
TaskHandle_t xInternalTaskHandle,
int32_t lInternalIndexOfKernelObject
)
{
uint32_t ulAccessControlListEntryIndex, ulAccessControlListEntryBit;
xMPU_SETTINGS * xTaskMpuSettings;
ulAccessControlListEntryIndex =
( ( uint32_t ) lInternalIndexOfKernelObject / portACL_ENTRY_SIZE_BITS );
ulAccessControlListEntryBit =
( ( uint32_t ) lInternalIndexOfKernelObject % portACL_ENTRY_SIZE_BITS );
xTaskMpuSettings = xTaskGetMPUSettings( xInternalTaskHandle );
xTaskMpuSettings->ulAccessControlList
[ ulAccessControlListEntryIndex ] |= ( 1U << ulAccessControlListEntryBit );
}
/* PRIVILEGED_FUNCTION */ void vPortRevokeAccessToKernelObject(
TaskHandle_t xInternalTaskHandle,
int32_t lInternalIndexOfKernelObject
)
{
uint32_t ulAccessControlListEntryIndex, ulAccessControlListEntryBit;
xMPU_SETTINGS * xTaskMpuSettings;
ulAccessControlListEntryIndex =
( ( uint32_t ) lInternalIndexOfKernelObject / portACL_ENTRY_SIZE_BITS );
ulAccessControlListEntryBit =
( ( uint32_t ) lInternalIndexOfKernelObject % portACL_ENTRY_SIZE_BITS );
xTaskMpuSettings = xTaskGetMPUSettings( xInternalTaskHandle );
xTaskMpuSettings->ulAccessControlList[ ulAccessControlListEntryIndex ] &= ~(
1U << ulAccessControlListEntryBit
);
}
#else
/* PRIVILEGED_FUNCTION */ BaseType_t xPortIsAuthorizedToAccessKernelObject(
int32_t lInternalIndexOfKernelObject
)
{
( void ) lInternalIndexOfKernelObject;
/* If Access Control List feature is not used, all the tasks have
* access to all the kernel objects. */
return pdTRUE;
}
#endif /* #if ( configENABLE_ACCESS_CONTROL_LIST == 1 ) */
/*---------------------------------------------------------------------------*/
/** @brief Function that is used as the default Link Register address for a new Task
*
* @ingroup Task Context
* @note This function is used as the default Link Register address if
* configTASK_RETURN_ADDRESS is not defined in FreeRTOSConfig.h
*
*/
void prvTaskExitError( void )
{
/* A function that implements a task must not exit or attempt to return to
* its caller as there is nothing to return to. If a task wants to exit it
* should instead call vTaskDelete( NULL ).
*
* Artificially force an assert() to be triggered if configASSERT() is
* defined, then stop here so application writers can catch the error. */
configASSERT( ulPortInterruptNesting == ~0UL );
for( ;; )
{
}
}
/*---------------------------------------------------------------------------*/
/** @brief Function meant to end the FreeRTOS Scheduler, not implemented on this port.
* @ingroup Scheduler
*/
void vPortEndScheduler( void )
{
xSchedulerRunning = pdFALSE;
/* Not implemented in ports where there is nothing to return to.
* Artificially force an assert. */
configASSERT( xSchedulerRunning );
}
/*---------------------------------------------------------------------------*/
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