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/*
* $Id$
*/
#include <stdio.h>
#include <dos.h>
#define IO_RTC 0x70 /* RTC */
#define RTC_SEC 0x00 /* seconds */
#define RTC_MIN 0x02 /* minutes */
#define RTC_HRS 0x04 /* hours */
#define RTC_WDAY 0x06 /* week day */
#define RTC_DAY 0x07 /* day of month */
#define RTC_MONTH 0x08 /* month of year */
#define RTC_YEAR 0x09 /* month of year */
#define RTC_STATUSA 0x0a /* status register A */
#define RTCSA_TUP 0x80 /* time update, don't look now */
#define RTC_STATUSB 0x0b /* status register B */
#define RTC_DIAG 0x0e /* status register E - bios diagnostic */
#define RTCDG_BITS "\020\010clock_battery\007ROM_cksum\006config_unit\005memory_size\004fixed_disk\003invalid_time"
/* convert 2 digit BCD number */
static int bcd( unsigned int i )
{
return ((i/16)*10 + (i%16));
}
static unsigned int rtcin( unsigned int what )
{
outportb( IO_RTC, what );
return inportb( IO_RTC+1 );
}
void fix_date( void )
{
int s;
struct date date;
struct time time;
/* initialize brain-dead battery powered clock */
outportb( IO_RTC, RTC_STATUSA );
outportb( IO_RTC+1, 0x26 );
outportb( IO_RTC, RTC_STATUSB );
outportb( IO_RTC+1, 2 );
outportb( IO_RTC, RTC_DIAG );
s = inportb( IO_RTC+1 );
if (s) printf("RTC BIOS diagnostic error %b\n", s, RTCDG_BITS);
/* check for presence of clock */
s = rtcin(RTC_STATUSA);
if ( s == 0xff || s == 0 ) {
printf( "Real-time clock not found\n" );
return;
}
/* ready for a read? */
while ((s & RTCSA_TUP) == RTCSA_TUP)
s = rtcin(RTC_STATUSA);
date.da_year = bcd(rtcin(RTC_YEAR)) + 1900; /* year */
if ( date.da_year < 1970) date.da_year += 100;
date.da_year -= 1980;
date.da_mon = bcd(rtcin(RTC_MONTH)); /* month */
date.da_day = bcd(rtcin(RTC_DAY)); /* day */
(void)bcd(rtcin(RTC_WDAY)); /* weekday */
time.ti_hour = bcd(rtcin(RTC_HRS)); /* hour */
time.ti_min = bcd(rtcin(RTC_MIN)); /* minutes */
time.ti_sec = bcd(rtcin(RTC_SEC)); /* seconds */
time.ti_hund = 0;
setdate( & date );
settime( & time );
}
void fix_timer( void )
{
#define PIT_PORT 0x40
#define TIMER_CNTR0 (PIT_PORT + 0) /* timer 0 counter port */
#define TIMER_MODE (PIT_PORT + 3) /* timer mode port */
#define TIMER_SEL0 0x00 /* select counter 0 */
#define TIMER_RATEGEN 0x04 /* mode 2, rate generator */
#define TIMER_16BIT 0x30 /* r/w counter 16 bits, LSB first */
/* set timer 0 to generate interrupts every period */
outportb( TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT );
outportb( TIMER_CNTR0, 0 ); /* counter low */
outportb( TIMER_CNTR0, 0 ); /* counter high */
}
int main(void)
{
/* Make timer count at correct pace */
fix_timer();
/* Fix the date */
fix_date();
return 0;
}
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