+++ /dev/null
-/* readclock - read the real time clock Authors: T. Holm & E. Froese */
-
-/************************************************************************/
-/* */
-/* readclock.c */
-/* */
-/* Read the clock value from the 64 byte CMOS RAM */
-/* area, then set system time. */
-/* */
-/* If the machine ID byte is 0xFC or 0xF8, the device */
-/* /dev/mem exists and can be opened for reading, */
-/* and no errors in the CMOS RAM are reported by the */
-/* RTC, then the time is read from the clock RAM */
-/* area maintained by the RTC. */
-/* */
-/* The clock RAM values are decoded and fed to mktime */
-/* to make a time_t value, then stime(2) is called. */
-/* */
-/* This fails if: */
-/* */
-/* If the machine ID does not match 0xFC or 0xF8 (no */
-/* error message.) */
-/* */
-/* If the machine ID is 0xFC or 0xF8 and /dev/mem */
-/* is missing, or cannot be accessed. */
-/* */
-/* If the RTC reports errors in the CMOS RAM. */
-/* */
-/************************************************************************/
-/* origination 1987-Dec-29 efth */
-/* robustness 1990-Oct-06 C. Sylvain */
-/* incorp. B. Evans ideas 1991-Jul-06 C. Sylvain */
-/* set time & calibrate 1992-Dec-17 Kees J. Bot */
-/* clock timezone 1993-Oct-10 Kees J. Bot */
-/* set CMOS clock 1994-Jun-12 Kees J. Bot */
-/************************************************************************/
-
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <time.h>
-#include <errno.h>
-#include <signal.h>
-#include <ibm/portio.h>
-#include <ibm/cmos.h>
-#include <sys/svrctl.h>
-
-int nflag = 0; /* Tell what, but don't do it. */
-int wflag = 0; /* Set the CMOS clock. */
-int Wflag = 0; /* Also set the CMOS clock register bits. */
-int y2kflag = 0; /* Interpret 1980 as 2000 for clock with Y2K bug. */
-
-char clocktz[128]; /* Timezone of the clock. */
-
-#define MACH_ID_ADDR 0xFFFFE /* BIOS Machine ID at FFFF:000E */
-
-#define PC_AT 0xFC /* Machine ID byte for PC/AT,
- PC/XT286, and PS/2 Models 50, 60 */
-#define PS_386 0xF8 /* Machine ID byte for PS/2 Model 80 */
-
-/* Manufacturers usually use the ID value of the IBM model they emulate.
- * However some manufacturers, notably HP and COMPAQ, have had different
- * ideas in the past.
- *
- * Machine ID byte information source:
- * _The Programmer's PC Sourcebook_ by Thom Hogan,
- * published by Microsoft Press
- */
-
-void errmsg(char *s);
-void get_time(struct tm *t);
-int read_register(int reg_addr);
-void set_time(struct tm *t);
-void write_register(int reg_addr, int value);
-int bcd_to_dec(int n);
-int dec_to_bcd(int n);
-void usage(void);
-
-int main(int argc, char **argv)
-{
- struct tm time1;
- struct tm time2;
- struct tm tmnow;
- char date[64];
- time_t now, rtc;
- int i, mem;
- unsigned char mach_id, cmos_state;
- struct sysgetenv sysgetenv;
-
- /* Open /dev/mem to get access to physical memory. */
- if ((mem = open("/dev/mem", O_RDONLY)) == -1) {
- errmsg( "Permission denied." );
- exit(1);
- }
- if (lseek(mem, (off_t) MACH_ID_ADDR, SEEK_SET) == -1
- || read(mem, (void *) &mach_id, sizeof(mach_id)) < 0) {
- mach_id = -1;
- }
- if (mach_id != PS_386 && mach_id != PC_AT) {
- errmsg( "Machine ID unknown." );
- fprintf( stderr, "Machine ID byte = %02x\n", mach_id );
-
- exit(1);
- }
- cmos_state = read_register(CMOS_STATUS);
- if (cmos_state & (CS_LOST_POWER | CS_BAD_CHKSUM | CS_BAD_TIME)) {
- errmsg( "CMOS RAM error(s) found..." );
- fprintf( stderr, "CMOS state = 0x%02x\n", cmos_state );
-
- if (cmos_state & CS_LOST_POWER)
- errmsg( "RTC lost power. Reset CMOS RAM with SETUP." );
- if (cmos_state & CS_BAD_CHKSUM)
- errmsg( "CMOS RAM checksum is bad. Run SETUP." );
- if (cmos_state & CS_BAD_TIME)
- errmsg( "Time invalid in CMOS RAM. Reset clock." );
- exit(1);
- }
-
- /* Process options. */
- while (argc > 1) {
- char *p = *++argv;
-
- if (*p++ != '-') usage();
-
- while (*p != 0) {
- switch (*p++) {
- case 'n': nflag = 1; break;
- case 'w': wflag = 1; break;
- case 'W': Wflag = 1; break;
- case '2': y2kflag = 1; break;
- default: usage();
- }
- }
- argc--;
- }
- if (Wflag) wflag = 1; /* -W implies -w */
-
- /* The hardware clock may run in a different time zone, likely GMT or
- * winter time. Select that time zone.
- */
- strcpy(clocktz, "TZ=");
- sysgetenv.key = "TZ";
- sysgetenv.keylen = 2+1;
- sysgetenv.val = clocktz+3;
- sysgetenv.vallen = sizeof(clocktz)-3;
- if (svrctl(SYSGETENV, &sysgetenv) == 0) {
- putenv(clocktz);
- tzset();
- }
-
- /* Read the CMOS real time clock. */
- for (i = 0; i < 10; i++) {
- get_time(&time1);
- now = time(NULL);
-
- time1.tm_isdst = -1; /* Do timezone calculations. */
- time2 = time1;
-
- rtc= mktime(&time1); /* Transform to a time_t. */
- if (rtc != -1) break;
-
- fprintf(stderr,
-"readclock: Invalid time read from CMOS RTC: %d-%02d-%02d %02d:%02d:%02d\n",
- time2.tm_year+1900, time2.tm_mon+1, time2.tm_mday,
- time2.tm_hour, time2.tm_min, time2.tm_sec);
- sleep(5);
- }
- if (i == 10) exit(1);
-
- if (!wflag) {
- /* Set system time. */
- if (nflag) {
- printf("stime(%lu)\n", (unsigned long) rtc);
- } else {
- if (stime(&rtc) < 0) {
- errmsg( "Not allowed to set time." );
- exit(1);
- }
- }
- tmnow = *localtime(&rtc);
- if (strftime(date, sizeof(date),
- "%a %b %d %H:%M:%S %Z %Y", &tmnow) != 0) {
- if (date[8] == '0') date[8]= ' ';
- printf("Result: %s\n", date);
- }
- } else {
- /* Set the CMOS clock to the system time. */
- tmnow = *localtime(&now);
- if (nflag) {
- printf("%04d-%02d-%02d %02d:%02d:%02d\n",
- tmnow.tm_year + 1900,
- tmnow.tm_mon + 1,
- tmnow.tm_mday,
- tmnow.tm_hour,
- tmnow.tm_min,
- tmnow.tm_sec);
- } else {
- set_time(&tmnow);
- }
- }
- exit(0);
-}
-
-void errmsg(char *s)
-{
- static char *prompt = "readclock: ";
-
- fprintf(stderr, "%s%s\n", prompt, s);
- prompt = "";
-}
-
-
-/***********************************************************************/
-/* */
-/* get_time( time ) */
-/* */
-/* Update the structure pointed to by time with the current time */
-/* as read from CMOS RAM of the RTC. */
-/* If necessary, the time is converted into a binary format before */
-/* being stored in the structure. */
-/* */
-/***********************************************************************/
-
-int dead;
-void timeout(int sig) { dead= 1; }
-
-void get_time(struct tm *t)
-{
- int osec, n;
- unsigned long i;
- struct sigaction sa;
-
- /* Start a timer to keep us from getting stuck on a dead clock. */
- sigemptyset(&sa.sa_mask);
- sa.sa_flags = 0;
- sa.sa_handler = timeout;
- sigaction(SIGALRM, &sa, NULL);
- dead = 0;
- alarm(5);
-
- do {
- osec = -1;
- n = 0;
- do {
- if (dead) {
- fprintf(stderr, "readclock: CMOS clock appears dead\n");
- exit(1);
- }
-
- /* Clock update in progress? */
- if (read_register(RTC_REG_A) & RTC_A_UIP) continue;
-
- t->tm_sec = read_register(RTC_SEC);
- if (t->tm_sec != osec) {
- /* Seconds changed. First from -1, then because the
- * clock ticked, which is what we're waiting for to
- * get a precise reading.
- */
- osec = t->tm_sec;
- n++;
- }
- } while (n < 2);
-
- /* Read the other registers. */
- t->tm_min = read_register(RTC_MIN);
- t->tm_hour = read_register(RTC_HOUR);
- t->tm_mday = read_register(RTC_MDAY);
- t->tm_mon = read_register(RTC_MONTH);
- t->tm_year = read_register(RTC_YEAR);
-
- /* Time stable? */
- } while (read_register(RTC_SEC) != t->tm_sec
- || read_register(RTC_MIN) != t->tm_min
- || read_register(RTC_HOUR) != t->tm_hour
- || read_register(RTC_MDAY) != t->tm_mday
- || read_register(RTC_MONTH) != t->tm_mon
- || read_register(RTC_YEAR) != t->tm_year);
-
- if ((read_register(RTC_REG_B) & RTC_B_DM_BCD) == 0) {
- /* Convert BCD to binary (default RTC mode). */
- t->tm_year = bcd_to_dec(t->tm_year);
- t->tm_mon = bcd_to_dec(t->tm_mon);
- t->tm_mday = bcd_to_dec(t->tm_mday);
- t->tm_hour = bcd_to_dec(t->tm_hour);
- t->tm_min = bcd_to_dec(t->tm_min);
- t->tm_sec = bcd_to_dec(t->tm_sec);
- }
- t->tm_mon--; /* Counts from 0. */
-
- /* Correct the year, good until 2080. */
- if (t->tm_year < 80) t->tm_year += 100;
-
- if (y2kflag) {
- /* Clock with Y2K bug, interpret 1980 as 2000, good until 2020. */
- if (t->tm_year < 100) t->tm_year += 20;
- }
-}
-
-
-int read_register(int reg_addr)
-{
- int r;
-
- intr_disable();
- outb(RTC_INDEX, reg_addr);
- r= inb(RTC_IO);
- intr_enable();
- return r;
-}
-
-
-
-/***********************************************************************/
-/* */
-/* set_time( time ) */
-/* */
-/* Set the CMOS RTC to the time found in the structure. */
-/* */
-/***********************************************************************/
-
-void set_time(struct tm *t)
-{
- int regA, regB;
-
- if (Wflag) {
- /* Set A and B registers to their proper values according to the AT
- * reference manual. (For if it gets messed up, but the BIOS doesn't
- * repair it.)
- */
- write_register(RTC_REG_A, RTC_A_DV_OK | RTC_A_RS_DEF);
- write_register(RTC_REG_B, RTC_B_24);
- }
-
- /* Inhibit updates. */
- regB= read_register(RTC_REG_B);
- write_register(RTC_REG_B, regB | RTC_B_SET);
-
- t->tm_mon++; /* Counts from 1. */
-
- if (y2kflag) {
- /* Set the clock back 20 years to avoid Y2K bug, good until 2020. */
- if (t->tm_year >= 100) t->tm_year -= 20;
- }
-
- if ((regB & 0x04) == 0) {
- /* Convert binary to BCD (default RTC mode) */
- t->tm_year = dec_to_bcd(t->tm_year % 100);
- t->tm_mon = dec_to_bcd(t->tm_mon);
- t->tm_mday = dec_to_bcd(t->tm_mday);
- t->tm_hour = dec_to_bcd(t->tm_hour);
- t->tm_min = dec_to_bcd(t->tm_min);
- t->tm_sec = dec_to_bcd(t->tm_sec);
- }
- write_register(RTC_YEAR, t->tm_year);
- write_register(RTC_MONTH, t->tm_mon);
- write_register(RTC_MDAY, t->tm_mday);
- write_register(RTC_HOUR, t->tm_hour);
- write_register(RTC_MIN, t->tm_min);
- write_register(RTC_SEC, t->tm_sec);
-
- /* Stop the clock. */
- regA= read_register(RTC_REG_A);
- write_register(RTC_REG_A, regA | RTC_A_DV_STOP);
-
- /* Allow updates and restart the clock. */
- write_register(RTC_REG_B, regB);
- write_register(RTC_REG_A, regA);
-}
-
-
-void write_register(int reg_addr, int value)
-{
- intr_disable();
- outb(RTC_INDEX, reg_addr);
- outb(RTC_IO, value);
- intr_enable();
-}
-
-int bcd_to_dec(int n)
-{
- return ((n >> 4) & 0x0F) * 10 + (n & 0x0F);
-}
-
-int dec_to_bcd(int n)
-{
- return ((n / 10) << 4) | (n % 10);
-}
-
-void usage(void)
-{
- fprintf(stderr, "Usage: readclock [-nwW2]\n");
- exit(1);
-}