toaruos/kernel/core/cmos.c

92 lines
1.9 KiB
C

/*
* CMOS Driver
*
* Part of the ToAruOS Kernel
* (C) 2011 Kevin Lange
*/
#include <system.h>
/* CMOS values are stored like so:
* Say it's 8:42 AM, then the values are stored as:
* 0x08, 0x42... why this was a good idea, I have no
* clue, but that's how it usually is.
*
* This function will convert between this "BCD" format
* and regular decimal integers. */
#define from_bcd(val) ((val / 16) * 10 + (val & 0xf))
void
cmos_dump(
uint16_t * values
) {
uint16_t index;
__asm__ __volatile__ ("cli");
for (index = 0; index < 128; ++index) {
outportb(0x70, index);
values[index] = inportb(0x71);
}
__asm__ __volatile__ ("sti");
}
/**
* Get the current month and day.
*
* @param month Pointer to a short to store the month
* @param day Pointer to a short to store the day
*/
void
get_date(
uint16_t * month,
uint16_t * day
) {
uint16_t values[128]; /* CMOS dump */
cmos_dump(values);
*month = from_bcd(values[8]);
*day = from_bcd(values[7]);
}
/**
* Get the current time.
*
* @param hours Pointer to a short to store the current hour (/24)
* @param minutes Pointer to a short to store the current minute
* @param seconds Pointer to a short to store the current second
*/
void
get_time(
uint16_t * hours,
uint16_t * minutes,
uint16_t * seconds
) {
uint16_t values[128]; /* CMOS dump */
cmos_dump(values);
*hours = from_bcd(values[4]);
*minutes = from_bcd(values[2]);
*seconds = from_bcd(values[0]);
}
int
gettimeofday(struct timeval * t, void *z) {
uint16_t values[128];
cmos_dump(values);
/* Math Time */
uint32_t time = (from_bcd(values[9]) - 70) * 31556926 +
from_bcd(values[8]) * 2629743 +
from_bcd(values[7]) * 87400 +
from_bcd(values[4]) * 3600 +
from_bcd(values[2]) * 60 +
from_bcd(values[0]);
t->tv_sec = time;
t->tv_usec = 0;
return 0;
}
/*
* vim:tabstop=4
* vim:noexpandtab
*/