FreeRTOS MPU: allow user control on CM55 devices with 16 MPU regions

Remove the assertion that forces the application to match
configTOTAL_MPU_REGIONS with the number of regions present in the
hardware.

This allows applications running on devices with 16 MPU regions to
control the second half, while the kernel retains control of the first.

Signed-off-by: Erick Reyes <erickreyes@google.com>
This commit is contained in:
Erick Reyes 2025-03-18 23:42:49 -07:00
parent dacce186cf
commit ed6ec5c73f

View file

@ -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 ) \
@ -925,64 +922,57 @@ 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 );
/* MAIR0 - Index 0. */
portMPU_MAIR0_REG |= ( ( portMPU_NORMAL_MEMORY_BUFFERABLE_CACHEABLE << portMPU_MAIR_ATTR0_POS ) & portMPU_MAIR_ATTR0_MASK );
/* MAIR0 - Index 1. */
portMPU_MAIR0_REG |= ( ( portMPU_DEVICE_MEMORY_nGnRE << portMPU_MAIR_ATTR1_POS ) & portMPU_MAIR_ATTR1_MASK );
/* 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. */
portMPU_MAIR0_REG |= ( ( portMPU_DEVICE_MEMORY_nGnRE << portMPU_MAIR_ATTR1_POS ) & portMPU_MAIR_ATTR1_MASK );
/* Setup privileged flash as Read Only so that privileged tasks can
* read it but not modify. */
portMPU_RNR_REG = portPRIVILEGED_FLASH_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __privileged_functions_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_PRIVILEGED_READ_ONLY );
portMPU_RLAR_REG = ( ( ( uint32_t ) __privileged_functions_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup privileged flash as Read Only so that privileged tasks can
* read it but not modify. */
portMPU_RNR_REG = portPRIVILEGED_FLASH_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __privileged_functions_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_PRIVILEGED_READ_ONLY );
portMPU_RLAR_REG = ( ( ( uint32_t ) __privileged_functions_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup unprivileged flash as Read Only by both privileged and
* unprivileged tasks. All tasks can read it but no-one can modify. */
portMPU_RNR_REG = portUNPRIVILEGED_FLASH_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __unprivileged_flash_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_READ_ONLY );
portMPU_RLAR_REG = ( ( ( uint32_t ) __unprivileged_flash_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup unprivileged flash as Read Only by both privileged and
* unprivileged tasks. All tasks can read it but no-one can modify. */
portMPU_RNR_REG = portUNPRIVILEGED_FLASH_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __unprivileged_flash_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_READ_ONLY );
portMPU_RLAR_REG = ( ( ( uint32_t ) __unprivileged_flash_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup unprivileged syscalls flash as Read Only by both privileged
* and unprivileged tasks. All tasks can read it but no-one can modify. */
portMPU_RNR_REG = portUNPRIVILEGED_SYSCALLS_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __syscalls_flash_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_READ_ONLY );
portMPU_RLAR_REG = ( ( ( uint32_t ) __syscalls_flash_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup unprivileged syscalls flash as Read Only by both privileged
* and unprivileged tasks. All tasks can read it but no-one can modify. */
portMPU_RNR_REG = portUNPRIVILEGED_SYSCALLS_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __syscalls_flash_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_READ_ONLY );
portMPU_RLAR_REG = ( ( ( uint32_t ) __syscalls_flash_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup RAM containing kernel data for privileged access only. */
portMPU_RNR_REG = portPRIVILEGED_RAM_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __privileged_sram_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_PRIVILEGED_READ_WRITE ) |
( portMPU_REGION_EXECUTE_NEVER );
portMPU_RLAR_REG = ( ( ( uint32_t ) __privileged_sram_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Setup RAM containing kernel data for privileged access only. */
portMPU_RNR_REG = portPRIVILEGED_RAM_REGION;
portMPU_RBAR_REG = ( ( ( uint32_t ) __privileged_sram_start__ ) & portMPU_RBAR_ADDRESS_MASK ) |
( portMPU_REGION_NON_SHAREABLE ) |
( portMPU_REGION_PRIVILEGED_READ_WRITE ) |
( portMPU_REGION_EXECUTE_NEVER );
portMPU_RLAR_REG = ( ( ( uint32_t ) __privileged_sram_end__ ) & portMPU_RLAR_ADDRESS_MASK ) |
( portMPU_RLAR_ATTR_INDEX0 ) |
( portMPU_RLAR_REGION_ENABLE );
/* Enable mem fault. */
portSCB_SYS_HANDLER_CTRL_STATE_REG |= portSCB_MEM_FAULT_ENABLE_BIT;
/* Enable mem fault. */
portSCB_SYS_HANDLER_CTRL_STATE_REG |= portSCB_MEM_FAULT_ENABLE_BIT;
/* Enable MPU with privileged background access i.e. unmapped
* regions have privileged access. */
portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
}
/* Enable MPU with privileged background access i.e. unmapped
* regions have privileged access. */
portMPU_CTRL_REG |= ( portMPU_PRIV_BACKGROUND_ENABLE_BIT | portMPU_ENABLE_BIT );
}
#endif /* configENABLE_MPU */