scripts/cmake/toolchains/bare-metal-gcc.cmake

#----------------------------------------------------------------------------
#  Copyright (c) 2021 Arm Limited. All rights reserved.
#  SPDX-License-Identifier: Apache-2.0
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
#----------------------------------------------------------------------------
# specify the cross compiler
set(TRIPLET                         arm-none-eabi)

set(CMAKE_C_COMPILER                ${TRIPLET}-gcc)
set(CMAKE_CXX_COMPILER              ${TRIPLET}-g++)

set(CMAKE_CROSSCOMPILING            true)
set(CMAKE_SYSTEM_NAME               Generic)

set(MIN_GCC_VERSION                 10.2.1)

# Skip compiler test execution
set(CMAKE_C_COMPILER_WORKS          1)
set(CMAKE_CXX_COMPILER_WORKS        1)
set(PLATFORM_HAL                    1)

if (NOT DEFINED CMAKE_SYSTEM_PROCESSOR)
    set(CMAKE_SYSTEM_PROCESSOR      cortex-m55)
endif()

if (CMAKE_SYSTEM_PROCESSOR STREQUAL cortex-m55)
    # Flags for cortex-m55
    set(CPU_COMPILE_DEF             CPU_CORTEX_M55)
    set(CPU_NAME                    ${CMAKE_SYSTEM_PROCESSOR})
    set(FLOAT_ABI                   hard)
    set(ARM_MATH_DSP                1)
    set(ARM_MATH_LOOPUNROLL         1)
elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL cortex-m33)
    # Flags for cortex-m33 to go here
endif()

set(${CPU_COMPILE_DEF}              1)

# Warning options
add_compile_options(
    -Wall
    -Wextra
    -Wvla
    -Wno-psabi)

# General purpose compile options:
add_compile_options(
    -funsigned-char
    -fno-function-sections
    "$<$<COMPILE_LANGUAGE:CXX>:-fno-unwind-tables;-fno-rtti;-fno-exceptions>")

# Arch compile options:
add_compile_options(
    -mthumb
    -mcpu=${CPU_NAME}
    -mfloat-abi=${FLOAT_ABI}
    -mlittle-endian
    -MD)

# Compile definitions:
add_compile_definitions(
    PLATFORM_HAL=${PLATFORM_HAL}
    ${CPU_COMPILE_DEF}=1
    $<$<BOOL:${ARM_MATH_DSP}>:ARM_MATH_DSP>
    $<$<BOOL:${ARM_MATH_LOOPUNROLL}>:ARM_MATH_LOOPUNROLL>)

# Link options:
add_link_options(
    -mthumb
    -mcpu=${CPU_NAME}
    -mfloat-abi=${FLOAT_ABI}
    -mlittle-endian
    --specs=nosys.specs
    --stats
    "$<$<CONFIG:RELEASE>:--no-debug>")

# Function to add a map file output for the linker to dump diagnostic information to.
function(add_target_map_file TARGET_NAME MAP_FILE_PATH)
    target_link_options(${TARGET_NAME} PUBLIC
        -Xlinker -Map=${MAP_FILE_PATH})
endfunction()

# Function to add linker option to use the chosen linker script.
function(add_linker_script SCRIPT_DIR SCRIPT_NAME)
    set(LINKER_SCRIPT_PATH ${SCRIPT_DIR}/${SCRIPT_NAME}.ld
        CACHE STRING "Linker script path")
    if (NOT EXISTS ${LINKER_SCRIPT_PATH})
        message(FATAL_ERROR "Linker script not found: ${LINKER_SCRIPT_PATH}")
    endif()
    message(STATUS "Using linker script: ${LINKER_SCRIPT_PATH}")
    add_link_options("SHELL:-T ${LINKER_SCRIPT_PATH}")
endfunction()

# Function to set the command to copy/extract contents from an elf
# into a binary file.
function(add_bin_generation_command)

    set(multiValueArgs SECTION_PATTERNS OUTPUT_BIN_NAMES)
    set(oneValueArgs TARGET_NAME OUTPUT_DIR AXF_PATH)
    cmake_parse_arguments(PARSED "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})

    list(LENGTH PARSED_SECTION_PATTERNS N_SECTION_PATTERNS)
    list(LENGTH PARSED_OUTPUT_BIN_NAMES N_OUTPUT_BIN_NAMES)

    if (NOT ${N_SECTION_PATTERNS} STREQUAL ${N_OUTPUT_BIN_NAMES})
        message(FATAL_ERROR "Section patterns and the output binary names "
                "should be of the same length")
    endif()

    message(STATUS "${TRIPLET}-objcopy requested to generate "
                   "${N_OUTPUT_BIN_NAMES} bin files.")

    math(EXPR MAX_IDX "${N_SECTION_PATTERNS} - 1")

    foreach(IDX RANGE ${MAX_IDX})

        list(GET PARSED_OUTPUT_BIN_NAMES ${IDX} OUTPUT_BIN_NAME)
        list(GET PARSED_SECTION_PATTERNS ${IDX} SECTION_PATTERN)

        add_custom_command(TARGET ${PARSED_TARGET_NAME}
            POST_BUILD
            COMMAND ${TRIPLET}-objcopy -O binary
            --only-section ${SECTION_PATTERN} ${PARSED_AXF_PATH}
            ${PARSED_OUTPUT_DIR}/${OUTPUT_BIN_NAME})
    endforeach()

endfunction()

# Function to assert the compiler version
function(enforce_compiler_version)
    if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${MIN_GCC_VERSION})
        message( FATAL_ERROR "arm-none-eabi-gcc version must be ${MIN_GCC_VERSION} or greater to support ${CMAKE_SYSTEM_PROCESSOR} architecture." )
    endif()
endfunction()