if (NOT MCU_CHIP)
    message(FATAL_ERROR "Missing required argument CHIP.")
elseif (MCU_CHIP MATCHES nrf51822)
    set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_LIST_DIR}/nrf51.cmake")
elseif (MCU_CHIP MATCHES D2000)
    set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_LIST_DIR}/intel-quark-d2000.toolchain.cmake")
else ()
    message(FATAL_ERROR "Unsupported MCU_CHIP setting: ${MCU_CHIP}")
endif ()