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chiptotime.c revision 1.4 
      1 /*	$NetBSD: chiptotime.c,v 1.4 2008/01/12 09:54:32 tsutsui 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(int sec, int min, int hour, int day, int mon, int year)
     32 {
     33 	int days, yr;
     34 
     35 	sec = FROMBCD(sec);
     36 	min = FROMBCD(min);
     37 	hour = FROMBCD(hour);
     38 	day = FROMBCD(day);
     39 	mon = FROMBCD(mon);
     40 	year = FROMBCD(year) + YEAR0;
     41 	if (year < 70)
     42 		year = 70;
     43 
     44 	/* simple sanity checks */
     45 	if (year < 70 || mon < 1 || mon > 12 || day < 1 || day > 31)
     46 		return (0);
     47 	days = 0;
     48 	for (yr = 70; yr < year; yr++)
     49 		days += LEAPYEAR(yr) ? 366 : 365;
     50 	days += dayyr[mon - 1] + day - 1;
     51 	if (LEAPYEAR(yr) && mon > 2)
     52 		days++;
     53 	/* now have days since Jan 1, 1970; the rest is easy... */
     54 	return days * SECDAY + hour * 3600 + min * 60 + sec;
     55 }
     56