Home | History | Annotate | Line # | Download | only in libsa
chiptotime.c revision 1.2 
      1 /*	$NetBSD: chiptotime.c,v 1.2 2005/06/28 21:03:02 junyoung Exp $ */
      2 
      3 #include <sys/types.h>
      4 
      5 #include <machine/prom.h>
      6 
      7 #include <lib/libsa/stand.h>
      8 #include "libsa.h"
      9 
     10 /*
     11  * BCD to decimal and decimal to BCD.
     12  */
     13 #define FROMBCD(x)      (int)((((unsigned int)(x)) >> 4) * 10 +\
     14 				(((unsigned int)(x)) & 0xf))
     15 #define TOBCD(x)        (int)((((unsigned int)(x)) / 10 * 16) +\
     16 				(((unsigned int)(x)) % 10))
     17 
     18 #define SECDAY          (24 * 60 * 60)
     19 #define SECYR           (SECDAY * 365)
     20 #define LEAPYEAR(y)     (((y) & 3) == 0)
     21 #define YEAR0		68
     22 
     23 /*
     24  * This code is defunct after 2068.
     25  * Will Unix still be here then??
     26  */
     27 const short dayyr[12] =
     28 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
     29 
     30 u_long
     31 chiptotime(sec, min, hour, day, mon, year)
     32 	int sec, min, hour, day, mon, year;
     33 {
     34 	int days, yr;
     35 
     36 	sec = FROMBCD(sec);
     37 	min = FROMBCD(min);
     38 	hour = FROMBCD(hour);
     39 	day = FROMBCD(day);
     40 	mon = FROMBCD(mon);
     41 	year = FROMBCD(year) + YEAR0;
     42 	if (year < 70)
     43 		year = 70;
     44 
     45 	/* simple sanity checks */
     46 	if (year < 70 || mon < 1 || mon > 12 || day < 1 || day > 31)
     47 		return (0);
     48 	days = 0;
     49 	for (yr = 70; yr < year; yr++)
     50 		days += LEAPYEAR(yr) ? 366 : 365;
     51 	days += dayyr[mon - 1] + day - 1;
     52 	if (LEAPYEAR(yr) && mon > 2)
     53 		days++;
     54 	/* now have days since Jan 1, 1970; the rest is easy... */
     55 	return (days * SECDAY + hour * 3600 + min * 60 + sec);
     56 }
     57