func IoctlRetInt(fd int, req uint) (int, error) {
	ret, _, err := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), 0)
	if err != 0 {
		return 0, err
	}
	return int(ret), nil
}

func IoctlGetUint32(fd int, req uint) (uint32, error) {
	var value uint32
	err := ioctlPtr(fd, req, unsafe.Pointer(&value))
	return value, err
}

func IoctlGetRTCTime(fd int) (*RTCTime, error) {
	var value RTCTime