cmostime.c

一个小型的操作系统,采用gcc进行开发,几千行的代码,方便初学者学习

/*
*  Snixos Project version 1.0, 2003.6
*  (C) Copyright 2003,2004,2005 Jockeyson,KeqiangGao <[e-mail]>
*  All Rights Reserved.
*  Distributed under the terms of the GNU General Public License.
*
*  This program is a free and open source software and you can redistribute 
*  it and/or modify it under the terms of the GNU General Public License as
*  published by the Free Software Foundation. As no any liability is assumed 
*  for any incidental or consequential damages in connection with the 
*  information or program fragments contained herein,so any exception arised
*  is at your own risk. It is ABSOLUTELY WITHOUT ANY WARRANTY.
*  Bug report please send to [e-mail] .
*/
/*
  cmostime.c: get system time from cmos
  Author    : [e-mail]
  Time      : 2003.6
*/

#include "cmostime.h"
#include "io.h"

#define GETCMOS(addr) ({ \
outb_delay(0x80|addr,0x70); \
inb_delay(0x71); \
})
/* cmose index address */
#define CMOS_SEC 0x0
#define CMOS_MIN 0x2
#define CMOS_HOUR 0x4
#define CMOS_WEEKDAY 0x6
#define CMOS_DAY 0x7
#define CMOS_MONTH 0x8
#define CMOS_YEAR 0x9
#define BCD_TO_BINARY(val) ((val)=((val)&15) + ((val)>>4)*10)
#define CENTURY 20

char *weekName[] = { "SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT" };

void getTime(struct tm *cmosTime)
{
    cmosTime->sec = GETCMOS(CMOS_SEC);
    cmosTime->min = GETCMOS(CMOS_MIN);
    cmosTime->hour = GETCMOS(CMOS_HOUR);
    cmosTime->dayofweek = GETCMOS(CMOS_WEEKDAY);
    cmosTime->day = GETCMOS(CMOS_DAY);
    cmosTime->month = GETCMOS(CMOS_MONTH);
    cmosTime->year = GETCMOS(CMOS_YEAR);
    BCD_TO_BINARY(cmosTime->sec);
    BCD_TO_BINARY(cmosTime->min);
    BCD_TO_BINARY(cmosTime->hour);
    BCD_TO_BINARY(cmosTime->day);
    BCD_TO_BINARY(cmosTime->month);
    BCD_TO_BINARY(cmosTime->year);
    cmosTime->weekname = weekName[cmosTime->dayofweek - 1];
    //cmosTime->month--;
    cmosTime->year += CENTURY * 100;
}

void cmosDelay(const int sec)
{
    struct tm time;
    int count, old_sec;
    count = sec;
    getTime(&time);
    old_sec = time.sec;
    while (count) {
	getTime(&time);
	if ((old_sec + 1) % 60 == time.sec) {
	    count--;
	    old_sec = time.sec;
	}
    }
}