cmake/modules/arch.cmake

# SPDX-License-Identifier: Apache-2.0
#
# Copyright (c) 2022, Nordic Semiconductor ASA

# Configure ARCH settings based on board directory and arch root.
#
# This CMake module will set the following variables in the build system based
# on board directory and arch root.
#
# If no implementation is available for the current arch an error will be raised.
#
# Outcome:
# The following variables will be defined when this CMake module completes:
#
# - ARCH:      Name of the arch in use.
# - ARCH_DIR:  Directory containing the arch implementation.
# - ARCH_ROOT: ARCH_ROOT with ZEPHYR_BASE appended
#
# Variable dependencies:
# - ARCH_ROOT: CMake list of arch roots containing arch implementations
# - BOARD_DIR: CMake variable specifying the directory of the selected BOARD
#
# Variables set by this module and not mentioned above are considered internal
# use only and may be removed, renamed, or re-purposed without prior notice.

include_guard(GLOBAL)

# 'ARCH_ROOT' is a prioritized list of directories where archs may be
# found. It always includes ${ZEPHYR_BASE} at the lowest priority.
list(APPEND ARCH_ROOT ${ZEPHYR_BASE})

cmake_path(GET BOARD_DIR PARENT_PATH board_arch_dir)
cmake_path(GET board_arch_dir FILENAME ARCH)

foreach(root ${ARCH_ROOT})
  if(EXISTS ${root}/arch/${ARCH}/CMakeLists.txt)
    set(ARCH_DIR ${root}/arch)
    break()
  endif()
endforeach()

if(NOT ARCH_DIR)
  message(FATAL_ERROR "Could not find ARCH=${ARCH} for BOARD=${BOARD}, \
please check your installation. ARCH roots searched: \n\
${ARCH_ROOT}")
endif()