/* Return a delta between the system time and the RTC time, such that system time can be restored later with restore_time_delta()  */
void save_time_delta(struct timespec *delta, struct timespec *rtc)
/* Return a delta between the system time and the RTC time, such that system time can be restored later with restore_time_delta()  */
void save_time_delta(struct timespec *delta, struct timespec *rtc)
{
	set_normalized_timespec(delta,
				xtime.tv_sec - rtc->tv_sec,
				xtime.tv_nsec - rtc->tv_nsec);
}