MPU assert for ARM_CM3_MPU (#952)
* Add runtime check to see if the target even has a MPU
* Add missing extern symbols for __ARMCC_VERSION support
* Add default for configTOTAL_MPU_REGIONS and change a runtime assert to compile time error
* Simplify check and link to reference documentation
Co-authored-by: Soren Ptak <ptaksoren@gmail.com>
---------
Co-authored-by: Soren Ptak <ptaksoren@gmail.com>
Co-authored-by: jasonpcarroll <23126711+jasonpcarroll@users.noreply.github.com>
diff --git a/portable/GCC/ARM_CM3_MPU/port.c b/portable/GCC/ARM_CM3_MPU/port.c
index d8c1832..fad62ff 100644
--- a/portable/GCC/ARM_CM3_MPU/port.c
+++ b/portable/GCC/ARM_CM3_MPU/port.c
@@ -1095,12 +1095,28 @@
static void prvSetupMPU( void )
{
- extern uint32_t __privileged_functions_start__[];
- extern uint32_t __privileged_functions_end__[];
- extern uint32_t __FLASH_segment_start__[];
- extern uint32_t __FLASH_segment_end__[];
- extern uint32_t __privileged_data_start__[];
- extern uint32_t __privileged_data_end__[];
+ #if defined( __ARMCC_VERSION )
+
+ /* Declaration when these variable are defined in code instead of being
+ * exported from linker scripts. */
+ extern uint32_t * __privileged_functions_start__;
+ extern uint32_t * __privileged_functions_end__;
+ extern uint32_t * __FLASH_segment_start__;
+ extern uint32_t * __FLASH_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 __privileged_functions_start__[];
+ extern uint32_t __privileged_functions_end__[];
+ extern uint32_t __FLASH_segment_start__[];
+ extern uint32_t __FLASH_segment_end__[];
+ extern uint32_t __privileged_data_start__[];
+ extern uint32_t __privileged_data_end__[];
+ #endif /* if defined( __ARMCC_VERSION ) */
+
+ /* Ensure that the device has the expected MPU type */
+ configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
/* Check the expected MPU is present. */
if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
@@ -1229,10 +1245,22 @@
StackType_t * pxBottomOfStack,
uint32_t ulStackDepth )
{
- extern uint32_t __SRAM_segment_start__[];
- extern uint32_t __SRAM_segment_end__[];
- extern uint32_t __privileged_data_start__[];
- extern uint32_t __privileged_data_end__[];
+ #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__[];
+ extern uint32_t __privileged_data_start__[];
+ extern uint32_t __privileged_data_end__[];
+ #endif /* if defined( __ARMCC_VERSION ) */
+
int32_t lIndex;
uint32_t ul;
diff --git a/portable/GCC/ARM_CM3_MPU/portmacro.h b/portable/GCC/ARM_CM3_MPU/portmacro.h
index 5983c79..a6e2ae2 100644
--- a/portable/GCC/ARM_CM3_MPU/portmacro.h
+++ b/portable/GCC/ARM_CM3_MPU/portmacro.h
@@ -86,6 +86,15 @@
#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 )
+#elif( configTOTAL_MPU_REGIONS != 8UL )
+ /* The Cortex M3 only supports 8 MPU regions. For more information refer to:
+ * https://developer.arm.com/documentation/dui0552/a/cortex-m3-peripherals/optional-memory-protection-unit */
+ #error configTOTAL_MPU_REGIONS must be 8 for this port.
+#endif /* configTOTAL_MPU_REGIONS Check */
#define portSTACK_REGION ( 3UL )
#define portGENERAL_PERIPHERALS_REGION ( 4UL )
#define portUNPRIVILEGED_FLASH_REGION ( 5UL )
