source: rtems/c/build-tools/os/msdos/fixtimer.c @ e2d79559

4.104.114.84.95
Last change on this file since e2d79559 was 1039ae4, checked in by Joel Sherrill <joel.sherrill@…>, on Sep 27, 1995 at 10:01:50 PM

new programs added

  • Property mode set to 100644
File size: 2.7 KB
Line 
1/*
2 *  $Id$
3 */
4
5#include <stdio.h>
6#include <dos.h>
7
8#define IO_RTC          0x70    /* RTC */
9
10#define RTC_SEC         0x00    /* seconds */
11#define RTC_MIN         0x02    /* minutes */
12#define RTC_HRS         0x04    /* hours */
13#define RTC_WDAY        0x06    /* week day */
14#define RTC_DAY         0x07    /* day of month */
15#define RTC_MONTH       0x08    /* month of year */
16#define RTC_YEAR        0x09    /* month of year */
17#define RTC_STATUSA     0x0a    /* status register A */
18#define  RTCSA_TUP       0x80   /* time update, don't look now */
19
20#define RTC_STATUSB     0x0b    /* status register B */
21
22#define RTC_DIAG        0x0e    /* status register E - bios diagnostic */
23#define RTCDG_BITS      "\020\010clock_battery\007ROM_cksum\006config_unit\005memory_size\004fixed_disk\003invalid_time"
24
25
26
27/* convert 2 digit BCD number */
28static int bcd( unsigned int i )
29{
30        return ((i/16)*10 + (i%16));
31}
32
33static unsigned int rtcin( unsigned int what )
34{
35    outportb( IO_RTC, what );
36    return inportb( IO_RTC+1 );
37}
38
39
40void fix_date( void )
41{
42    int s;
43    struct date date;
44    struct time time;
45
46    /* initialize brain-dead battery powered clock */
47    outportb( IO_RTC, RTC_STATUSA );
48    outportb( IO_RTC+1, 0x26 );
49    outportb( IO_RTC, RTC_STATUSB );
50    outportb( IO_RTC+1, 2 );
51
52    outportb( IO_RTC, RTC_DIAG );
53    s = inportb( IO_RTC+1 );
54    if (s) printf("RTC BIOS diagnostic error %b\n", s, RTCDG_BITS);
55
56    /* check for presence of clock */
57    s = rtcin(RTC_STATUSA);
58    if ( s == 0xff  ||  s == 0 )  {
59        printf( "Real-time clock not found\n" );
60        return;
61    }
62
63    /* ready for a read? */
64    while ((s & RTCSA_TUP) == RTCSA_TUP)
65        s = rtcin(RTC_STATUSA);
66
67    date.da_year        = bcd(rtcin(RTC_YEAR)) + 1900;  /* year   */
68    if ( date.da_year < 1970)   date.da_year += 100;
69    date.da_year        -= 1980;
70    date.da_mon         = bcd(rtcin(RTC_MONTH));        /* month   */
71    date.da_day         = bcd(rtcin(RTC_DAY));          /* day     */
72
73    (void)bcd(rtcin(RTC_WDAY));         /* weekday */
74
75    time.ti_hour        = bcd(rtcin(RTC_HRS));          /* hour    */
76    time.ti_min         = bcd(rtcin(RTC_MIN));          /* minutes */
77    time.ti_sec         = bcd(rtcin(RTC_SEC));          /* seconds */
78    time.ti_hund        = 0;
79
80    setdate( & date );
81    settime( & time );
82}
83
84
85
86
87void fix_timer( void )
88{
89#define PIT_PORT        0x40
90#define TIMER_CNTR0     (PIT_PORT + 0)  /* timer 0 counter port */
91#define TIMER_MODE      (PIT_PORT + 3)  /* timer mode port */
92#define   TIMER_SEL0    0x00            /* select counter 0 */
93#define   TIMER_RATEGEN 0x04            /* mode 2, rate generator */
94#define   TIMER_16BIT   0x30            /* r/w counter 16 bits, LSB first */
95
96    /* set timer 0 to generate interrupts every period */
97    outportb( TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT );
98    outportb( TIMER_CNTR0, 0 );  /* counter low */
99    outportb( TIMER_CNTR0, 0 );  /* counter high */
100}
101
102int main(void)
103{
104    /* Make timer count at correct pace */
105    fix_timer();
106
107    /* Fix the date */
108    fix_date();
109
110    return 0;
111}
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