arch/common/Kconfig

# Common architecture configuration options

# Copyright (c) 2022, CSIRO.
# SPDX-License-Identifier: Apache-2.0

config SEMIHOST
	bool "Semihosting support for ARM, RISC-V and Xtensa targets"
	depends on ARM || ARM64 || RISCV || (XTENSA && !SIMULATOR_XTENSA)
	help
	  Semihosting is a mechanism that enables code running on an ARM, RISC-V
	  or Xtensa target to communicate and use the Input/Output facilities on
	  a host computer that is running a debugger.
	  Additional information can be found in:
	  https://developer.arm.com/documentation/dui0471/m/what-is-semihosting-
	  https://github.com/riscv-non-isa/riscv-semihosting/blob/main/riscv-semihosting.adoc
	  This option is compatible with hardware and with QEMU, through the
	  (automatic) use of the -semihosting-config switch when invoking it.

config ISR_TABLE_SHELL
	bool "Shell command to dump the ISR tables"
	depends on GEN_SW_ISR_TABLE
	depends on SHELL
	help
	  This option enables a shell command to dump the ISR tables.

config ARCH_SUPPORTS_ROM_OFFSET
	bool
	default y
	depends on  (ARM || X86 || ARM64 || RISCV || ARC)
	help
	  Hidden option to enable support for ROM offset within the linker
	  script, which will place a block of 0x0 of size
	  CONFIG_ROM_START_OFFSET at the start of the ROM region.

config ARM_MPU
	bool "ARM MPU Support"
	select MPU
	select SRAM_REGION_PERMISSIONS
	select THREAD_STACK_INFO
	select ARCH_HAS_EXECUTABLE_PAGE_BIT if (CPU_AARCH32_CORTEX_R || CPU_CORTEX_M)
	select MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT if !(CPU_HAS_NXP_SYSMPU || ARMV8_M_BASELINE || ARMV8_M_MAINLINE || AARCH32_ARMV8_R)
	select MPU_REQUIRES_NON_OVERLAPPING_REGIONS if CPU_HAS_ARM_MPU && (ARMV8_M_BASELINE || ARMV8_M_MAINLINE || AARCH32_ARMV8_R)
	select MPU_GAP_FILLING if AARCH32_ARMV8_R
	select ARCH_MEM_DOMAIN_SUPPORTS_ISOLATED_STACKS if (CPU_AARCH32_CORTEX_R || CPU_CORTEX_M)
	select ARCH_MEM_DOMAIN_SYNCHRONOUS_API if USERSPACE && CPU_AARCH64_CORTEX_R
	default y if CPU_AARCH64_CORTEX_R
	depends on CPU_HAS_MPU
	help
	  MCU implements Memory Protection Unit.

	  Notes:
	  The ARMv6-M, ARMv7-M, and ARMv8-R MPU MPU architecture requires a power-of-two
	  alignment of MPU region base address and size.

	  The NXP MPU as well as the ARMv8-M MPU do not require MPU regions
	  to have power-of-two alignment for base address and region size.

	  The ARMv8-M and ARMv8-R MPU requires the active MPU regions be non-overlapping.
	  As a result of this, both respective MPUs needs to fully partition the
	  memory map when programming dynamic memory regions (e.g. PRIV stack
	  guard, user thread stack, and application memory domains), if the
	  system requires PRIV access policy different from the access policy
	  of the ARMv8-M or ARMv8-R background memory map. The application developer may
	  enforce full PRIV (kernel) memory partition by enabling the
	  MPU_GAP_FILLING option.
	  By not enforcing full partition, MPU may leave part of kernel
	  SRAM area covered only by the default ARMv8-M or ARMv8-R memory map. This
	  is fine for User Mode, since the background ARM map does not
	  allow nPRIV access at all. However, since the background map
	  policy allows instruction fetches by privileged code, forcing
	  this Kconfig option off prevents the system from directly
	  triggering MemManage exceptions upon accidental attempts to
	  execute code from SRAM in XIP builds.
	  Since this does not compromise User Mode, we make the skipping
	  of full partitioning the default behavior for the ARMv8-M and ARMv8-R MPU
	  driver.