esp-idf/components/ulp/project_include.cmake

# ulp_embed_binary
#
# Create ULP binary and embed into the application.
function(ulp_embed_binary app_name s_sources exp_dep_srcs)
    if(NOT CMAKE_BUILD_EARLY_EXPANSION)
        spaces2list(s_sources)
        foreach(source ${s_sources})
            get_filename_component(source ${source} ABSOLUTE BASE_DIR ${CMAKE_CURRENT_LIST_DIR})
            list(APPEND sources ${source})
        endforeach()

        foreach(source ${sources})
            get_filename_component(ps_source ${source} NAME_WE)
            set(ps_output ${CMAKE_CURRENT_BINARY_DIR}/${app_name}/${ps_source}.ulp.S)
            list(APPEND ps_sources ${ps_output})
        endforeach()

        set(ulp_artifacts_prefix ${CMAKE_CURRENT_BINARY_DIR}/${app_name}/${app_name})

        set(ulp_artifacts ${ulp_artifacts_prefix}.bin
                            ${ulp_artifacts_prefix}.ld
                            ${ulp_artifacts_prefix}.h)

        set(ulp_artifacts_extras ${ulp_artifacts_prefix}.map
                            ${ulp_artifacts_prefix}.sym
                            ${CMAKE_CURRENT_BINARY_DIR}/${app_name}/esp32.ulp.ld)

        # Replace the separator for the list of ULP source files that will be passed to
        # the external ULP project. This is a workaround to the bug https://public.kitware.com/Bug/view.php?id=16137.
        string(REPLACE ";" "|" ulp_s_sources "${ulp_s_sources}")

        idf_build_get_property(sdkconfig_header SDKCONFIG_HEADER)
        idf_build_get_property(idf_path IDF_PATH)
        idf_build_get_property(python PYTHON)
        idf_build_get_property(extra_cmake_args EXTRA_CMAKE_ARGS)

        externalproject_add(${app_name}
            SOURCE_DIR ${idf_path}/components/ulp/cmake
            BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${app_name}
            INSTALL_COMMAND ""
            CMAKE_ARGS  -DCMAKE_GENERATOR=${CMAKE_GENERATOR}
                        -DCMAKE_TOOLCHAIN_FILE=${idf_path}/components/ulp/cmake/toolchain-ulp.cmake
                        -DULP_S_SOURCES=${sources} -DULP_APP_NAME=${app_name}
                        -DCOMPONENT_DIR=${COMPONENT_DIR}
                        # Even though this resolves to a ';' separated list, this is fine. This must be special behavior
                        # for generator expressions.
                        -DCOMPONENT_INCLUDES=$<TARGET_PROPERTY:${COMPONENT_TARGET},INTERFACE_INCLUDE_DIRECTORIES>
                        -DIDF_PATH=${idf_path}
                        -DSDKCONFIG=${SDKCONFIG_HEADER}
                        -DPYTHON=${python}
                        ${extra_cmake_args}
            BUILD_COMMAND ${CMAKE_COMMAND} --build ${CMAKE_CURRENT_BINARY_DIR}/${app_name} --target build
            BUILD_BYPRODUCTS ${ulp_artifacts} ${ulp_artifacts_extras} ${ulp_ps_sources}
                            ${CMAKE_CURRENT_BINARY_DIR}/${app_name}/${app_name}
            BUILD_ALWAYS 1
            LIST_SEPARATOR |
            )

        spaces2list(exp_dep_srcs)
        set_source_files_properties(${exp_dep_srcs} PROPERTIES OBJECT_DEPENDS ${ulp_artifacts})

        include_directories(${CMAKE_CURRENT_BINARY_DIR}/${app_name})

        add_custom_target(${app_name}_artifacts DEPENDS ${app_name})

        add_dependencies(${COMPONENT_LIB} ${app_name}_artifacts)

        target_linker_script(${COMPONENT_LIB} INTERFACE ${CMAKE_CURRENT_BINARY_DIR}/${app_name}/${app_name}.ld)
        target_add_binary_data(${COMPONENT_LIB} ${CMAKE_CURRENT_BINARY_DIR}/${app_name}/${app_name}.bin BINARY)
    endif()
endfunction()