private static uint CTL_CODE(uint DeviceType, uint Function, uint Method, uint Access)

        uint IOCTL_HAL_REBOOT = CTL_CODE(FILE_DEVICE_HAL, 15, METHOD_BUFFERED, FILE_ANY_ACCESS);

FSCTL constants are found in WinIoCtl.h, using CTL_CODE()function to Logical OR together FILE_DEVICE_FILE_SYSTEM (9) shifted left 16 places;