freebsd-dev/sys/boot/i386/libi386/time.c

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/*
* mjs copyright
*/
#include <stand.h>
#include <btxv86.h>
/*
* Return the time in seconds since the beginning of the day.
*
* If we pass midnight, don't wrap back to 0.
*
* XXX uses undocumented BCD support from libstand.
*/
time_t
time(time_t *t)
{
static time_t lasttime, now;
int hr, min, sec;
v86.ctl = 0;
v86.addr = 0x1a; /* int 0x1a, function 2 */
v86.eax = 0x0200;
v86int();
hr = bcd2bin((v86.ecx & 0xff00) >> 8); /* hour in %ch */
min = bcd2bin(v86.ecx & 0xff); /* minute in %cl */
sec = bcd2bin((v86.edx & 0xff00) >> 8); /* second in %dh */
now = hr * 3600 + min * 60 + sec;
if (now < lasttime)
now += 24 * 3600;
lasttime = now;
if (t != NULL)
*t = now;
return(now);
}
/*
* Use the BIOS Wait function to pause for (period) microseconds.
*
* Resolution of this function is variable, but typically around
* 1ms.
*/
void
delay(int period)
{
v86.ctl = 0;
v86.addr = 0x15; /* int 0x1a, function 0x86 */
v86.eax = 0x8600;
v86.ecx = period >> 16;
v86.edx = period & 0xffff;
v86int();
}