The MPU hal provides a simple MPU API to enhance device security by preventing execution from ram. More...

Modules
	MPU hal tests
	The MPU test validates proper implementation of the MPU hal.

Functions
void	mbed_mpu_init (void)
	Initialize the MPU. More...

void	mbed_mpu_enable_rom_wn (bool enable)
	Enable or disable ROM MPU protection. More...

void	mbed_mpu_enable_ram_xn (bool enable)
	Enable or disable ram MPU protection. More...

void	mbed_mpu_free (void)
	Deinitialize the MPU. More...

Detailed Description

The MPU hal provides a simple MPU API to enhance device security by preventing execution from ram.

Defined behavior

The function mbed_mpu_init is safe to call repeatedly - Verified by mpu_init_test
The function mbed_mpu_free disables MPU protection - Verified by mpu_free_test
Execution from RAM results in a fault when execute never is enabled. This RAM includes heap, stack, data and zero init - Verified by mpu_fault_test_data, mpu_fault_test_bss, mpu_fault_test_stack and mpu_fault_test_heap.
Writing to ROM results in a fault when write never is enabled - Not verified

Calling any function other than mbed_mpu_init before the initialization of the MPU.

void mbed_mpu_init ( void )

Initialize the MPU.

Initialize or re-initialize the memory protection unit. After initialization or re-initialization, ROM and RAM protection are both enabled.

void mbed_mpu_enable_rom_wn ( bool enable )

Enable or disable ROM MPU protection.

This function is used to mark all of ROM as read and execute only. When enabled writes to ROM cause a fault.

By default writes to ROM are disabled.

Parameters

enable true to disable writes to ROM, false otherwise

void mbed_mpu_enable_ram_xn ( bool enable )

Enable or disable ram MPU protection.

This function is used to mark all of RAM as execute never. When enabled code is only allowed to execute from flash.

By default execution from RAM is disabled.

Parameters

enable true to disable execution from RAM, false otherwise

void mbed_mpu_free ( void )

Deinitialize the MPU.

Powerdown the MPU in preparation for powerdown, reset or jumping to another application.