macro(subdirlist result curdir)
    file(GLOB children RELATIVE ${curdir} ${curdir}/*)
    set(dirlist "")
    foreach (child ${children})
        if (IS_DIRECTORY ${curdir}/${child})
            list(APPEND dirlist ${child})
        endif()
    endforeach()
    set(${result} ${dirlist})
endmacro()

function (platform_config)
    set(available_platforms "")
    set(available_platforms_list "")
    subdirlist(platforms ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys)

    foreach (platform ${platforms})
        subdirlist(machines ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${platform}/machine)
        foreach (machine ${machines})
            set(available_platforms "${available_platforms}${machine}-${platform} ")
            list(APPEND available_platforms_list ${machine}-${platform})
        endforeach (machine)
    endforeach (platform)

    if (${ARGC} LESS 1)
        message(FATAL_ERROR "No target specified!\n"
            "Available targets: ${available_platforms}")
    endif ()

    set(target ${ARGV0})

    list(FIND available_platforms_list ${target} target_idx)

    if (${target_idx} EQUAL -1)
        message(FATAL_ERROR "${target} is not a valid target!\n"
        "Available targets: ${available_platforms}")
    endif ()

    string(REPLACE "-" ";" target_parts ${target})
    list(GET target_parts 1 platform)
    list(GET target_parts 0 machine)
    set(machine ${machine} PARENT_SCOPE)
    set(platform ${platform} PARENT_SCOPE)
endfunction (platform_config)