1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific prior written permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 * 12 * @(#)clock.h 7.1 (Berkeley) 05/21/88 13 */ 14 15 #define SECDAY ((unsigned)(24*60*60)) /* seconds per day */ 16 #define SECYR ((unsigned)(365*SECDAY)) /* per common year */ 17 18 #define YRREF 1970 19 #define LEAPYEAR(year) ((year)%4==0) /* good till time becomes negative */ 20 21 /* 22 * Software clock is software interrupt level 8 23 */ 24 #define setsoftclock() mtpr(SIRR, 0x8) 25 26 /* 27 * To calculate value for interval timer register, we 28 * use the fact that 20512 yields a 60hz clock. 29 */ 30 #define hztocount(v) ((20512*60) / (v)) 31