Add support for 16 MPU regions to Cortex-M4 MPU ports (#96)

ARMv7-M supports 8 or 16 MPU regions. FreeRTOS Cortex-M4 MPU ports so
far assumed 8 regions. This change adds support for 16 MPU regions. The
hardware with 16 MPU regions must define configTOTAL_MPU_REGIONS to 16
in their FreeRTOSConfig.h.

If left undefined, it defaults to 8 for backward compatibility.

Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
This commit is contained in:
Gaurav-Aggarwal-AWS 2020-07-24 07:47:41 -07:00 committed by GitHub
parent 367faab135
commit 7dd6b76011
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7 changed files with 167 additions and 98 deletions

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@ -76,7 +76,7 @@
#define portMPU_REGION_BASE_ADDRESS_REG ( *( ( volatile uint32_t * ) 0xe000ed9C ) )
#define portMPU_REGION_ATTRIBUTE_REG ( *( ( volatile uint32_t * ) 0xe000edA0 ) )
#define portMPU_CTRL_REG ( *( ( volatile uint32_t * ) 0xe000ed94 ) )
#define portEXPECTED_MPU_TYPE_VALUE ( 8UL << 8UL ) /* 8 regions, unified. */
#define portEXPECTED_MPU_TYPE_VALUE ( portTOTAL_NUM_REGIONS << 8UL )
#define portMPU_ENABLE ( 0x01UL )
#define portMPU_BACKGROUND_ENABLE ( 1UL << 2UL )
#define portPRIVILEGED_EXECUTION_START_ADDRESS ( 0UL )
@ -527,6 +527,12 @@ static void prvSetupMPU( void )
extern uint32_t __privileged_data_start__[];
extern uint32_t __privileged_data_end__[];
/* The only permitted number of regions are 8 or 16. */
configASSERT( ( portTOTAL_NUM_REGIONS == 8 ) || ( portTOTAL_NUM_REGIONS == 16 ) );
/* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
/* Check the expected MPU is present. */
if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
{

View file

@ -91,10 +91,23 @@ xPortPendSVHandler:
/* Region Base Address register. */
ldr r2, =0xe000ed9c
/* Read 4 sets of MPU registers. */
/* Read 4 sets of MPU registers [MPU Region # 4 - 7]. */
ldmia r1!, {r4-r11}
/* Write 4 sets of MPU registers. */
stmia r2!, {r4-r11}
/* Write 4 sets of MPU registers [MPU Region # 4 - 7]. */
stmia r2, {r4-r11}
#ifdef configTOTAL_MPU_REGIONS
#if ( configTOTAL_MPU_REGIONS == 16 )
/* Read 4 sets of MPU registers [MPU Region # 8 - 11]. */
ldmia r1!, {r4-r11}
/* Write 4 sets of MPU registers. [MPU Region # 8 - 11]. */
stmia r2, {r4-r11}
/* Read 4 sets of MPU registers [MPU Region # 12 - 15]. */
ldmia r1!, {r4-r11}
/* Write 4 sets of MPU registers. [MPU Region # 12 - 15]. */
stmia r2, {r4-r11}
#endif /* configTOTAL_MPU_REGIONS == 16. */
#endif /* configTOTAL_MPU_REGIONS */
ldr r2, =0xe000ed94 /* MPU_CTRL register. */
ldr r3, [r2] /* Read the value of MPU_CTRL. */
@ -178,10 +191,23 @@ vPortRestoreContextOfFirstTask:
/* Region Base Address register. */
ldr r2, =0xe000ed9c
/* Read 4 sets of MPU registers. */
/* Read 4 sets of MPU registers [MPU Region # 4 - 7]. */
ldmia r1!, {r4-r11}
/* Write 4 sets of MPU registers. */
stmia r2!, {r4-r11}
/* Write 4 sets of MPU registers [MPU Region # 4 - 7]. */
stmia r2, {r4-r11}
#ifdef configTOTAL_MPU_REGIONS
#if ( configTOTAL_MPU_REGIONS == 16 )
/* Read 4 sets of MPU registers [MPU Region # 8 - 11]. */
ldmia r1!, {r4-r11}
/* Write 4 sets of MPU registers. [MPU Region # 8 - 11]. */
stmia r2, {r4-r11}
/* Read 4 sets of MPU registers [MPU Region # 12 - 15]. */
ldmia r1!, {r4-r11}
/* Write 4 sets of MPU registers. [MPU Region # 12 - 15]. */
stmia r2, {r4-r11}
#endif /* configTOTAL_MPU_REGIONS == 16. */
#endif /* configTOTAL_MPU_REGIONS */
ldr r2, =0xe000ed94 /* MPU_CTRL register. */
ldr r3, [r2] /* Read the value of MPU_CTRL. */

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@ -84,15 +84,21 @@
#define portMPU_REGION_CACHEABLE_BUFFERABLE ( 0x07UL << 16UL )
#define portMPU_REGION_EXECUTE_NEVER ( 0x01UL << 28UL )
/* MPU settings that can be overriden in FreeRTOSConfig.h. */
#ifndef configTOTAL_MPU_REGIONS
/* Define to 8 for backward compatibility. */
#define configTOTAL_MPU_REGIONS ( 8UL )
#endif
#define portUNPRIVILEGED_FLASH_REGION ( 0UL )
#define portPRIVILEGED_FLASH_REGION ( 1UL )
#define portPRIVILEGED_RAM_REGION ( 2UL )
#define portGENERAL_PERIPHERALS_REGION ( 3UL )
#define portSTACK_REGION ( 4UL )
#define portFIRST_CONFIGURABLE_REGION ( 5UL )
#define portLAST_CONFIGURABLE_REGION ( 7UL )
#define portNUM_CONFIGURABLE_REGIONS ( ( portLAST_CONFIGURABLE_REGION - portFIRST_CONFIGURABLE_REGION ) + 1 )
#define portTOTAL_NUM_REGIONS ( portNUM_CONFIGURABLE_REGIONS + 1 ) /* Plus one to make space for the stack region. */
#define portTOTAL_NUM_REGIONS ( configTOTAL_MPU_REGIONS )
#define portNUM_CONFIGURABLE_REGIONS ( portTOTAL_NUM_REGIONS - portFIRST_CONFIGURABLE_REGION )
#define portLAST_CONFIGURABLE_REGION ( portTOTAL_NUM_REGIONS - 1UL )
#define portSWITCH_TO_USER_MODE() __asm volatile ( " mrs r0, control \n orr r0, r0, #1 \n msr control, r0 " ::: "r0", "memory" )