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# Kconfig - Memory Protection Unit (MPU) configuration options
#
# Copyright (c) 2017 Linaro Limited
#
# SPDX-License-Identifier: Apache-2.0
#
if CPU_HAS_MPU
config ARM_MPU
bool "ARM MPU Support"
select MEMORY_PROTECTION
select THREAD_STACK_INFO
select ARCH_HAS_EXECUTABLE_PAGE_BIT
select MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT if !(CPU_HAS_NXP_MPU || ARMV8_M_BASELINE || ARMV8_M_MAINLINE)
select MPU_REQUIRES_NON_OVERLAPPING_REGIONS if CPU_HAS_ARM_MPU && (ARMV8_M_BASELINE || ARMV8_M_MAINLINE)
help
MCU implements Memory Protection Unit.
Note that NXP MPU as well as ARMv8-M MPU does not require MPU regions
to have power-of-two alignment for base address and region size.
In addition to the above, ARMv8-M MPU requires the active MPU regions
be non-overlapping.
config ARM_MPU_REGION_MIN_ALIGN_AND_SIZE
int
default 32 if ARM_MPU
default 4
help
Minimum size (and alignment) of an ARM MPU region. Use this
symbol to guarantee minimum size and alignment of MPU regions.
A minimum 4-byte alignment is enforced in ARM builds without
support for Memory Protection.
if ARM_MPU
config MPU_STACK_GUARD
bool "Thread Stack Guards"
help
Enable Thread Stack Guards via MPU
if MPU_STACK_GUARD
config MPU_STACK_GUARD_MIN_SIZE_FLOAT
int
depends on FP_SHARING
default 128
help
Minimum size (and alignment when applicable) of an ARM MPU
region, which guards the stack of a thread that is using the
Floating Point (FP) context. The width of the guard is set to
128, to accommodate the length of a Cortex-M exception stack
frame when the floating point context is active. The FP context
is only stacked in sharing FP registers mode, therefore, the
option is applicable only when FP_SHARING is selected.
endif # MPU_STACK_GUARD
config MPU_ALLOW_FLASH_WRITE
bool "Add MPU access to write to flash"
help
Enable this to allow MPU RWX access to flash memory
endif # ARM_MPU
endif # CPU_HAS_MPU