Function getit

freebsd/x86/isa/clock.c:204–219

}

static int
getit(void)
{
	int high, low;

	mtx_lock_spin(&clock_lock);

	/* Select timer0 and latch counter value. */
	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);

	low = inb(TIMER_CNTR0);
	high = inb(TIMER_CNTR0);

	mtx_unlock_spin(&clock_lock);
	return ((high << 8) | low);
}

/*
 * Wait "n" microseconds.