# ARM Cortex-M platform configuration options

# Copyright (c) 2014-2015 Wind River Systems, Inc.
# SPDX-License-Identifier: Apache-2.0

# NOTE: We have the specific core implementations first and outside of the
# if CPU_CORTEX_M block so that SoCs can select which core they are using
# without having to select all the options related to that core.  Everything
# else is captured inside the if CPU_CORTEX_M block so they are not exposed
# if one select a different ARM Cortex Family (Cortex-A or Cortex-R)

config CPU_CORTEX_M0
	bool
	select CPU_CORTEX_M
	select ARMV6_M_ARMV8_M_BASELINE
	help
	  This option signifies the use of a Cortex-M0 CPU

config CPU_CORTEX_M0PLUS
	bool
	select CPU_CORTEX_M
	select ARMV6_M_ARMV8_M_BASELINE
	help
	  This option signifies the use of a Cortex-M0+ CPU

config CPU_CORTEX_M1
	bool
	select CPU_CORTEX_M
	select ARMV6_M_ARMV8_M_BASELINE
	help
	  This option signifies the use of a Cortex-M1 CPU

config CPU_CORTEX_M3
	bool
	select CPU_CORTEX_M
	select ARMV7_M_ARMV8_M_MAINLINE
	help
	  This option signifies the use of a Cortex-M3 CPU

config CPU_CORTEX_M4
	bool
	select CPU_CORTEX_M
	select ARMV7_M_ARMV8_M_MAINLINE
	select ARMV7_M_ARMV8_M_FP if CPU_HAS_FPU
	help
	  This option signifies the use of a Cortex-M4 CPU

config CPU_CORTEX_M23
	bool
	select CPU_CORTEX_M
	select ARMV8_M_BASELINE
	select ARMV8_M_SE if CPU_HAS_TEE
	help
	  This option signifies the use of a Cortex-M23 CPU

config CPU_CORTEX_M33
	bool
	select CPU_CORTEX_M
	select ARMV8_M_MAINLINE
	select ARMV8_M_SE if CPU_HAS_TEE
	select ARMV7_M_ARMV8_M_FP if CPU_HAS_FPU
	help
	  This option signifies the use of a Cortex-M33 CPU

config CPU_CORTEX_M55
	bool
	select CPU_CORTEX_M
	select ARMV8_1_M_MAINLINE
	select ARMV8_M_SE if CPU_HAS_TEE
	select ARMV7_M_ARMV8_M_FP if CPU_HAS_FPU
	help
	  This option signifies the use of a Cortex-M55 CPU

config CPU_CORTEX_M7
	bool
	select CPU_CORTEX_M
	select ARMV7_M_ARMV8_M_MAINLINE
	select ARMV7_M_ARMV8_M_FP if CPU_HAS_FPU
	help
	  This option signifies the use of a Cortex-M7 CPU

if CPU_CORTEX_M

config CPU_CORTEX_M_HAS_SYSTICK
	bool
	help
	  This option is enabled when the CPU implements the SysTick timer.

config CPU_CORTEX_M_HAS_DWT
	bool
	depends on !CPU_CORTEX_M0 && !CPU_CORTEX_M0PLUS && !CPU_CORTEX_M1
	help
	  This option signifies that the CPU implements the Data Watchpoint and
	  Trace (DWT) unit specified by the ARMv7-M and above.

	  While ARMv6-M does define a "DWT" unit, this is significantly different
	  from the DWT specified by the ARMv7-M and above in terms of both feature
	  set and register mappings.

config CPU_CORTEX_M_HAS_BASEPRI
	bool
	depends on ARMV7_M_ARMV8_M_MAINLINE
	help
	  This option signifies the CPU has the BASEPRI register.

	  The BASEPRI register defines the minimum priority for
	  exception processing. When BASEPRI is set to a nonzero
	  value, it prevents the activation of all exceptions with
	  the same or lower priority level as the BASEPRI value.
	  Always present in CPUs that implement the ARMv7-M or
	  ARM8-M Mainline architectures.

config CPU_CORTEX_M_HAS_VTOR
	bool
	depends on !CPU_CORTEX_M0 && !CPU_CORTEX_M1
	help
	  This option signifies the CPU has the VTOR register.
	  The VTOR indicates the offset of the vector table base
	  address from memory address 0x00000000. Always present
	  in CPUs implementing the ARMv7-M or ARMv8-M architectures.
	  Optional in CPUs implementing ARMv6-M, ARMv8-M Baseline
	  architectures (except for Cortex-M0/M1, where it is never
	  implemented).

config CPU_CORTEX_M_HAS_SPLIM
	bool
	depends on ARMV8_M_MAINLINE || (ARMV8_M_SE && !ARM_NONSECURE_FIRMWARE)
	help
	  This option signifies the CPU has the MSPLIM, PSPLIM registers.

	  The stack pointer limit registers, MSPLIM, PSPLIM, limit the
	  extend to which the Main and Process Stack Pointers, respectively,
	  can descend. MSPLIM, PSPLIM are always present in ARMv8-M
	  MCUs that implement the ARMv8-M Main Extension (Mainline).

	  In an ARMv8-M Mainline implementation with the Security Extension
	  the MSPLIM, PSPLIM registers have additional Secure instances.
	  In an ARMv8-M Baseline implementation with the Security Extension
	  the MSPLIM, PSPLIM registers have only Secure instances.

config CPU_CORTEX_M_HAS_PROGRAMMABLE_FAULT_PRIOS
	bool
	depends on ARMV7_M_ARMV8_M_MAINLINE
	help
	  This option signifies the CPU may trigger system faults
	  (other than HardFault) with configurable priority, and,
	  therefore, it needs to reserve a priority level for them.

config CPU_CORTEX_M0_HAS_VECTOR_TABLE_REMAP
	bool
	depends on ARMV6_M_ARMV8_M_BASELINE
	help
	  This option signifies the Cortex-M0 has some mechanisms that can map
	  the vector table to SRAM

config CPU_CORTEX_M_HAS_CMSE
	bool
	depends on ARMV8_M_BASELINE || ARMV8_M_MAINLINE
	help
	  This option signifies the Cortex-M CPU has the CMSE intrinsics.

config ARMV6_M_ARMV8_M_BASELINE
	bool
	select ATOMIC_OPERATIONS_C
	select ISA_THUMB2
	help
	  This option signifies the use of an ARMv6-M processor
	  implementation, or the use of an ARMv8-M processor
	  supporting the Baseline implementation.

	  Notes:
	  - A Processing Element (PE) without the Main Extension
	  is also referred to as a Baseline Implementation. A
	  Baseline implementation has a subset of the instructions,
	  registers, and features, of a Mainline implementation.
	  - ARMv6-M compatibility is provided by all ARMv8-M
	  implementations.

config ARMV8_M_BASELINE
	bool
	select ARMV6_M_ARMV8_M_BASELINE
	select CPU_CORTEX_M_HAS_CMSE
	help
	  This option signifies the use of an ARMv8-M processor
	  implementation.

	  ARMv8-M Baseline includes additional features
	  not present in the ARMv6-M architecture.

config ARMV7_M_ARMV8_M_MAINLINE
	bool
	select ATOMIC_OPERATIONS_BUILTIN
	select ISA_THUMB2
	select CPU_CORTEX_M_HAS_BASEPRI
	select CPU_CORTEX_M_HAS_VTOR
	select CPU_CORTEX_M_HAS_PROGRAMMABLE_FAULT_PRIOS
	select CPU_CORTEX_M_HAS_SYSTICK
	help
	  This option signifies the use of an ARMv7-M processor
	  implementation, or the use of a backwards-compatible
	  ARMv8-M processor implementation supporting the Main
	  Extension.

	  Notes:
	  - A Processing Element (PE) with the Main Extension is also
	  referred to as a Mainline Implementation.
	  - ARMv7-M compatibility requires the Main Extension.

	  From https://developer.arm.com/products/architecture/m-profile:
	  The Main Extension provides backwards compatibility
	  with ARMv7-M.

config ARMV8_M_MAINLINE
	bool
	select ARMV7_M_ARMV8_M_MAINLINE
	select CPU_CORTEX_M_HAS_SPLIM
	select CPU_CORTEX_M_HAS_CMSE
	help
	  This option signifies the use of an ARMv8-M processor
	  implementation, supporting the Main Extension.

	  ARMv8-M Main Extension includes additional features
	  not present in the ARMv7-M architecture.

config ARMV8_1_M_MAINLINE
	bool
	select ARMV8_M_MAINLINE
	help
	  This option signifies the use of an ARMv8.1-M processor
	  implementation, supporting the Main Extension.

	  ARMv8.1-M Main Extension includes additional features
	  not present in the ARMv8-M architecture.

config ARMV8_M_SE
	bool
	depends on ARMV8_M_BASELINE || ARMV8_M_MAINLINE
	select CPU_CORTEX_M_HAS_SPLIM if !ARM_NONSECURE_FIRMWARE
	help
	  This option signifies the use of an ARMv8-M processor
	  implementation (Baseline or Mainline) supporting the
	  Security Extensions.

config ARMV7_M_ARMV8_M_FP
	bool
	depends on ARMV7_M_ARMV8_M_MAINLINE && !CPU_CORTEX_M3
	imply FPU_SHARING
	help
	  This option signifies the use of an ARMv7-M processor
	  implementation, or the use of an ARMv8-M processor
	  implementation supporting the Floating-Point Extension.

config ARMV8_M_DSP
	bool
	depends on ARMV8_M_MAINLINE
	help
	  This option signifies the use of an ARMv8-M processor
	  implementation supporting the DSP Extension.

config ARMV8_1_M_MVEI
	bool
	depends on ARMV8_1_M_MAINLINE
	depends on ARMV8_M_DSP
	help
	  This option signifies the use of an ARMv8.1-M processor implementation
	  supporting the M-Profile Vector Extension (MVE) integer instruction set.

config ARMV8_1_M_MVEF
	bool
	depends on ARMV8_1_M_MVEI
	help
	  This option signifies the use of an ARMv8.1-M processor implementation
	  supporting the M-Profile Vector Extension (MVE) floating-point
	  instruction set.

menu "ARM Cortex-M0/M0+/M1/M3/M4/M7/M23/M33 options"
    depends on ARMV6_M_ARMV8_M_BASELINE || ARMV7_M_ARMV8_M_MAINLINE

config GEN_ISR_TABLES
	default y

config ZERO_LATENCY_IRQS
	bool "Zero-latency interrupts"
	depends on CPU_CORTEX_M_HAS_BASEPRI
	help
	  The kernel may reserve some of the highest interrupts priorities in
	  the system for its own use. These interrupts will not be masked
	  by interrupt locking.
	  When connecting interrupts the kernel will offset all interrupts
	  to lower priority than those reserved by the kernel.
	  Zero-latency interrupt can be used to set up an interrupt at the
	  highest interrupt priority which will not be blocked by interrupt
	  locking.
	  Since Zero-latency ISRs will run in the same priority or possibly at
	  higher priority than the rest of the kernel they cannot use any
	  kernel functionality.

config DYNAMIC_DIRECT_INTERRUPTS
	bool "Support for dynamic direct interrupts"
	depends on DYNAMIC_INTERRUPTS
	help
	  Direct interrupts are designed for performance-critical interrupt
	  handling and do not go through all of the common interrupt handling
	  code. This option enables the installation of interrupt service
	  routines for direct interrupts at runtime.
	  Note: this requires enabling support for dynamic interrupts in the
	  kernel.

config SW_VECTOR_RELAY
	bool "Software Vector Relay"
	help
	  When building a bootloader firmware this option adds a
	  vector table relay handler and a vector relay table, to
	  relay interrupts based on a vector table pointer.
	  This is only required but not limited to Cortex-M Baseline CPUs
	  with no hardware vector table relocation mechanisms (e.g. VTOR).

config SW_VECTOR_RELAY_CLIENT
	bool "Software Vector Relay (client)"
	default y if BOOTLOADER_MCUBOOT && !CPU_CORTEX_M0_HAS_VECTOR_TABLE_REMAP
	depends on !CPU_CORTEX_M_HAS_VTOR
	help
	  Another image has enabled SW_VECTOR_RELAY, and will be forwarding
	  exceptions and HW interrupts to this image. Enable this option to make
	  sure the vector table pointer in RAM is set properly by the image upon
	  initialization.

config CORTEX_M_DWT
	bool "Data Watchpoint and Trace (DWT)"
	depends on CPU_CORTEX_M_HAS_DWT
	default y if TIMING_FUNCTIONS
	help
	  Enable and use the Data Watchpoint and Trace (DWT) unit for
	  timing functions.

# Additional stack for tests when building with FPU_SHARING
# enabled, which may increase ESF stacking requirements for
# threads.
config TEST_EXTRA_STACK_SIZE
	default 512 if TEST_ARM_CORTEX_M && FPU_SHARING

config TRAP_UNALIGNED_ACCESS
	bool "Unaligned access trap"
	depends on !ARMV6_M_ARMV8_M_BASELINE
	help
	  If enabled, the CPU generates a UsageFault exception when executing a
	  halfword or word access.

endmenu

# Implement the null pointer detection using either the Data Watchpoint and
# Trace Unit and the Debug Monitor Exception, or the Memory Protection Unit.

choice NULL_POINTER_EXCEPTION_DETECTION
	bool "Null-pointer exception"
	# Disable this until https://github.com/zephyrproject-rtos/zephyr/issues/32984 is fixed
	# default NULL_POINTER_EXCEPTION_DETECTION_DWT if TEST_ARM_CORTEX_M && !ARM_NONSECURE_FIRMWARE && CPU_CORTEX_M_HAS_DWT
	default NULL_POINTER_EXCEPTION_DETECTION_MPU if TEST_ARM_CORTEX_M && !ARM_NONSECURE_FIRMWARE && ARM_MPU && !CPU_CORTEX_M_HAS_DWT
	default NULL_POINTER_EXCEPTION_DETECTION_NONE
	help
	  There are 2 implementations available, one based
	  on DWT and the other based on MPU. Use this choice
	  symbol to select one of the options. By default the
	  feature is disabled. In the test suite the feature
	  is enabled and the DWT-based solution is preferred.

config NULL_POINTER_EXCEPTION_DETECTION_NONE
	bool "No null pointer exception detection"
	help
	  Null pointer exception detection feature is not
	  enabled.

config NULL_POINTER_EXCEPTION_DETECTION_DWT
	bool "Use DWT for null pointer exception detection"
	depends on CPU_CORTEX_M_HAS_DWT
	depends on !TRUSTED_EXECUTION_NONSECURE
	select CORTEX_M_DWT
	select CORTEX_M_NULL_POINTER_EXCEPTION
	help
	  Null pointer dereference detection implemented
	  using the DWT unit functionality.
	  Notes:
	  - Not enabled for Non-Secure FW images, where
	  null-pointer dereferencing is likely caught as
	  a SecureFault.
	  - Requires DWT functionality in the Cortex-M SoC
	  implementation (1 comparator for ARMv7-M, 2 comparators
	  for ARMv8-M).
	  - Requires the Cortex-M core be in normal mode.

config NULL_POINTER_EXCEPTION_DETECTION_MPU
	bool "Use MPU for null pointer exception detection"
	depends on !TRUSTED_EXECUTION_NONSECURE
	depends on ARM_MPU
	select CORTEX_M_NULL_POINTER_EXCEPTION
	help
	  Null pointer dereference detection implemented
	  using MPU functionality.
	  Notes:
	  - Mutually exclusive to the DWT-based solution
	  - Not enabled for Non-Secure FW images, where
	  null-pointer dereferencing is likely caught as
	  a SecureFault.
	  - Requires MPU functionality to be present and
	  enabled. The implementation consumes 1 MPU region.
	  - In ARMv8-M, explicit null-pointer dereference
	  detection with MPU requires, additionally, that
	  the area: [0x0,
	  CORTEX_M_NULL_POINTER_EXCEPTION_PAGE_SIZE)
	  is not unmapped (covered by an MPU region already).
	  If it is unmapped null-pointer dereferencing may
	  still be indirectly detected (e.g. via a precise
	  Bus access fault), but this is not guaranteed. A
	  build-time message warns the user of this scenario.

endchoice

config CORTEX_M_NULL_POINTER_EXCEPTION
	bool
	help
	  Enable and use the null pointer exception option.
	  This is a debug feature in Cortex-M, allowing for
	  detecting null pointer dereferencing (raising a
	  CPU fault). Supporting the feature results in an
	  increased code footprint, determined by option
	  CORTEX_M_NULL_POINTER_EXCEPTION_PAGE_SIZE.

	  Note: this hidden option is selected by the choice
	  symbols corresponding to the DWT-based or to the
	  MPU-based solution.

if CORTEX_M_NULL_POINTER_EXCEPTION

config CORTEX_M_NULL_POINTER_EXCEPTION_PAGE_SIZE
	hex "Size of paged unmapped to implement null pointer detection"
	default 0x400
	help
	  Size of the page reserved for detecting null pointer
	  dereferencing. Must be a power of two. A large value
	  offers enhanced detection performance to the cost of
	  wasting a large flash area that code may not use.

endif # CORTEX_M_NULL_POINTER_EXCEPTION

rsource "tz/Kconfig"

endif # CPU_CORTEX_M