isEmpty(_cpu_pri){
    _cpu_pri="oneshot"
    include($$PWD/../CPU/CMSIS/CMSIS.pri)
    include($$PWD/../CPU/USB/USB.pri)
    include($$PWD/../CPU/STM32F4xx_StdPeriph_Driver/STM32F4xx_StdPeriph_Driver.pri)
    include($$PWD/core.pri)

    INCLUDEPATH += \
	    $$PWD/../CPU/STM32F4xx_StdPeriph_Driver/inc \
	    $$PWD/../CPU/CMSIS/Include

    SOURCES += $$PWD/../CPU/cpu.c \
                $$PWD/../CPU/cpuinit.c \
                $$PWD/../CPU/syscalls.c \
                $$PWD/../CPU/fs.c \
                $$PWD/../CPU/crt0.s
}