ESP-Nodes/ESP32-IDF_Temperture-Node-v2/managed_components/espressif__cmake_utilities/relinker.cmake

# @brief Link designated functions from SRAM to Flash to save SRAM
if(CONFIG_CU_RELINKER_ENABLE)
    # project_elf variable is only in project.cmake
    if(NOT TARGET customer_sections AND DEFINED project_elf)
        message(STATUS "Relinker is enabled.")
        if(CONFIG_IDF_TARGET_ESP32C2)
            set(target "esp32c2")
        else()
            message(FATAL_ERROR "Other targets are not supported.")
        endif()

        if(CONFIG_CU_RELINKER_ENABLE_CUSTOMIZED_CONFIGURATION_FILES)
            idf_build_get_property(project_dir PROJECT_DIR)
            get_filename_component(cfg_file_path "${CONFIG_CU_RELINKER_CUSTOMIZED_CONFIGURATION_FILES_PATH}"
                                ABSOLUTE BASE_DIR "${project_dir}")

            if(NOT EXISTS "${cfg_file_path}")
                message(FATAL_ERROR "Relinker Configuration files path ${cfg_file_path} is not found.")
            endif()
        else()
            set(cfg_file_path ${PROJECT_DIR}/relinker/${target})
            if(NOT EXISTS ${cfg_file_path})
                set(cfg_file_path ${CMAKE_CURRENT_LIST_DIR}/scripts/relinker/examples/${target})
            endif()
        endif()

        message(STATUS "Relinker configuration files: ${cfg_file_path}")

        set(library_file "${cfg_file_path}/library.csv")
        set(object_file "${cfg_file_path}/object.csv")
        set(function_file "${cfg_file_path}/function.csv")
        set(relinker_script "${CMAKE_CURRENT_LIST_DIR}/scripts/relinker/relinker.py")

        set(cmake_objdump "${CMAKE_OBJDUMP}")
        set(link_path "${CMAKE_BINARY_DIR}/esp-idf/esp_system/ld")
        set(link_src_file "${link_path}/sections.ld")
        set(link_dst_file "${link_path}/customer_sections.ld")

        set(relinker_opts --input     ${link_src_file}
                        --output    ${link_dst_file}
                        --library   ${library_file}
                        --object    ${object_file}
                        --function  ${function_file}
                        --sdkconfig ${sdkconfig}
                        --objdump   ${cmake_objdump})

        if(CONFIG_CU_RELINKER_ENABLE_PRINT_ERROR_INFO_WHEN_MISSING_FUNCTION)
            list(APPEND relinker_opts --missing_function_info True)
        endif()

        idf_build_get_property(link_depends __LINK_DEPENDS)

        add_custom_command(OUTPUT ${link_dst_file}
                            COMMAND ${python} -B ${relinker_script}
                                    ${relinker_opts}
                            COMMAND ${CMAKE_COMMAND} -E copy
                                    ${link_dst_file}
                                    ${link_src_file}
                            COMMAND ${CMAKE_COMMAND} -E echo
                                    /*relinker*/ >>
                                    ${link_dst_file}
                            DEPENDS "${link_depends}"
                                    "${library_file}"
                                    "${object_file}"
                                    "${function_file}"
                            VERBATIM)
        
        add_custom_target(customer_sections DEPENDS ${link_dst_file})
        add_dependencies(${project_elf} customer_sections)
    endif()
else()
    message(STATUS "Relinker isn't enabled.")
endif()