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Annotation of 43BSDReno/sys/vax/clock.c, revision 1.1

1.1     ! root        1: 
        !             2: /*
        !             3:  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
        !             4:  * All rights reserved.  The Berkeley software License Agreement
        !             5:  * specifies the terms and conditions for redistribution.
        !             6:  *
        !             7:  *     @(#)clock.c     7.5 (Berkeley) 3/13/90
        !             8:  */
        !             9: 
        !            10: #include "param.h"
        !            11: #include "time.h"
        !            12: #include "kernel.h"
        !            13: 
        !            14: #include "mtpr.h"
        !            15: #include "clock.h"
        !            16: #include "cpu.h"
        !            17: 
        !            18: /*
        !            19:  * Machine-dependent clock routines.
        !            20:  *
        !            21:  * Startrtclock restarts the real-time clock, which provides
        !            22:  * hardclock interrupts to kern_clock.c.
        !            23:  *
        !            24:  * Inittodr initializes the time of day hardware which provides
        !            25:  * date functions.  Its primary function is to use some file
        !            26:  * system information in case the hardare clock lost state.
        !            27:  *
        !            28:  * Resettodr restores the time of day hardware after a time change.
        !            29:  */
        !            30: 
        !            31: /*
        !            32:  * Start the real-time clock.
        !            33:  */
        !            34: startrtclock()
        !            35: {
        !            36: 
        !            37:        (*cpuops->cpu_clock->clkstartrt)();
        !            38: }
        !            39: 
        !            40: /*
        !            41:  * Initialze the time of day register, based on the time base which is, e.g.
        !            42:  * from a filesystem.  Base provides the time to within six months,
        !            43:  * and the time of year clock (if any) provides the rest.
        !            44:  */
        !            45: inittodr(base)
        !            46:        time_t base;
        !            47: {
        !            48:        long deltat, badbase = 0;
        !            49: 
        !            50:        if (base < 5*SECYR) {
        !            51:                printf("WARNING: preposterous time in file system\n");
        !            52:                /* read the system clock anyway */
        !            53:                base = 6*SECYR + 186*SECDAY + SECDAY/2;
        !            54:                badbase = 1;
        !            55:        }
        !            56:        switch ((*cpuops->cpu_clock->clkread)(base)) {
        !            57: 
        !            58:        case CLKREAD_BAD:
        !            59:                /*
        !            60:                 * Believe the time in the file system for lack of
        !            61:                 * anything better, resetting the TODR.
        !            62:                 */
        !            63:                time.tv_sec = base;
        !            64:                if (!badbase)
        !            65:                        resettodr();
        !            66:                break;
        !            67: 
        !            68:        case CLKREAD_WARN:
        !            69:                break;
        !            70: 
        !            71:        case CLKREAD_OK:
        !            72:                if (badbase)
        !            73:                        break;
        !            74:                /*
        !            75:                 * See if we gained/lost two or more days;
        !            76:                 * if so, assume something is amiss.
        !            77:                 */
        !            78:                deltat = time.tv_sec - base;
        !            79:                if (deltat < 0)
        !            80:                        deltat = -deltat;
        !            81:                if (deltat < 2 * SECDAY)
        !            82:                        return;
        !            83:                printf("WARNING: clock %s %d days",
        !            84:                    time.tv_sec < base ? "lost" : "gained", deltat / SECDAY);
        !            85:                break;
        !            86: 
        !            87:        default:
        !            88:                panic("inittodr");
        !            89:                /* NOTREACHED */
        !            90:        }
        !            91:        printf(" -- CHECK AND RESET THE DATE!\n");
        !            92: }
        !            93: 
        !            94: /*
        !            95:  * Reset the TODR based on the time value; used when the TODR
        !            96:  * has a preposterous value, when the time is changed, and when rebooting.
        !            97:  * Also called when the TODR goes past TODRZERO + 100*(SECYEAR+2*SECDAY)
        !            98:  * (e.g. on Jan 2 just after midnight) to wrap the TODR around.
        !            99:  * Avoid doing this if we haven't figured out the time yet
        !           100:  * (e.g., when crashing during autoconfig).
        !           101:  */
        !           102: resettodr()
        !           103: {
        !           104: 
        !           105:        if (time.tv_sec)
        !           106:                (*cpuops->cpu_clock->clkwrite)();
        !           107: }
        !           108: 
        !           109: /*
        !           110:  * ``Standard'' VAX clock routines.
        !           111:  */
        !           112: #if VAX8600 || VAX8200 || VAX780 || VAX750 || VAX730
        !           113: vaxstd_clkstartrt()
        !           114: {
        !           115: 
        !           116:        mtpr(NICR, -1000000/hz);
        !           117:        mtpr(ICCS, ICCS_RUN+ICCS_IE+ICCS_TRANS+ICCS_INT+ICCS_ERR);
        !           118: }
        !           119: #endif
        !           120: 
        !           121: #if VAX8600 || VAX780 || VAX750 || VAX730 || VAX650
        !           122: vaxstd_clkread(base)
        !           123:        time_t base;
        !           124: {
        !           125:        register u_int todr = mfpr(TODR);
        !           126:        int year;
        !           127: 
        !           128:        /*
        !           129:         * TODRZERO is base used by VMS, which runs on local time.
        !           130:         */
        !           131:        if (todr < TODRZERO) {
        !           132:                printf("WARNING: todr too small");
        !           133:                return (CLKREAD_BAD);
        !           134:        }
        !           135: 
        !           136:        /*
        !           137:         * Sneak to within 6 months of the time in the filesystem,
        !           138:         * by starting with the time of the year suggested by the TODR,
        !           139:         * and advancing through succesive years.  Adding the number of
        !           140:         * seconds in the current year takes us to the end of the current year
        !           141:         * and then around into the next year to the same position.
        !           142:         */
        !           143:        time.tv_sec = (todr - TODRZERO) / 100;
        !           144:        year = YRREF;
        !           145:        while (time.tv_sec < base - SECYR/2) {
        !           146:                if (LEAPYEAR(year))
        !           147:                        time.tv_sec += SECDAY;
        !           148:                year++;
        !           149:                time.tv_sec += SECYR;
        !           150:        }
        !           151: 
        !           152:        return (CLKREAD_OK);
        !           153: }
        !           154: 
        !           155: vaxstd_clkwrite()
        !           156: {
        !           157:        int year = YRREF;
        !           158:        u_int secyr;
        !           159:        u_int yrtime = time.tv_sec;
        !           160: 
        !           161:        /*
        !           162:         * Whittle the time down to an offset in the current year,
        !           163:         * by subtracting off whole years as long as possible.
        !           164:         */
        !           165:        for (;;) {
        !           166:                secyr = SECYR;
        !           167:                if (LEAPYEAR(year))
        !           168:                        secyr += SECDAY;
        !           169:                if (yrtime < secyr)
        !           170:                        break;
        !           171:                yrtime -= secyr;
        !           172:                year++;
        !           173:        }
        !           174:        mtpr(TODR, TODRZERO + yrtime*100);
        !           175: }
        !           176: #endif
        !           177: 
        !           178: #if VAX8200 || VAX630
        !           179: /*
        !           180:  * This code is defunct after 2099.
        !           181:  * Will Unix still be here then??
        !           182:  */
        !           183: short dayyr[12] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
        !           184: 
        !           185: chiptotime(c)
        !           186:        register struct chiptime *c;
        !           187: {
        !           188:        register int days, yr;
        !           189: 
        !           190:        /* simple sanity checks */
        !           191:        if (c->year < 70 || c->mon < 1 || c->mon > 12 ||
        !           192:            c->day < 1 || c->day > 31) {
        !           193:                printf("WARNING: preposterous clock chip time");
        !           194:                return (0);
        !           195:        }
        !           196:        days = 0;
        !           197:        for (yr = 70; yr < c->year; yr++)
        !           198:                days += LEAPYEAR(yr) ? 366 : 365;
        !           199:        days += dayyr[c->mon - 1] + c->day - 1;
        !           200:        if (LEAPYEAR(yr) && c->mon > 2)
        !           201:                days++;
        !           202:        /* now have days since Jan 1, 1970; the rest is easy... */
        !           203:        return (days * SECDAY + c->hour * 3600 + c->min * 60 + c->sec);
        !           204: }
        !           205: 
        !           206: timetochip(c)
        !           207:        register struct chiptime *c;
        !           208: {
        !           209:        register int t, t2, t3;
        !           210: 
        !           211:        /* compute the year */
        !           212:        t2 = time.tv_sec / SECDAY;
        !           213:        t = 69;
        !           214:        while (t2 >= 0) {       /* whittle off years */
        !           215:                t3 = t2;
        !           216:                t++;
        !           217:                t2 -= LEAPYEAR(t) ? 366 : 365;
        !           218:        }
        !           219:        c->year = t;
        !           220: 
        !           221:        /* t3 = month + day; separate */
        !           222:        t = LEAPYEAR(t);
        !           223:        for (t2 = 1; t2 < 12; t2++)
        !           224:                if (t3 < dayyr[t2] + (t && t2 > 1))
        !           225:                        break;
        !           226: 
        !           227:        /* t2 is month */
        !           228:        c->mon = t2;
        !           229:        c->day = t3 - dayyr[t2 - 1] + 1;
        !           230:        if (t && t2 > 2)
        !           231:                c->day--;
        !           232: 
        !           233:        /* the rest is easy */
        !           234:        t = time.tv_sec % SECDAY;
        !           235:        c->hour = t / 3600;
        !           236:        t %= 3600;
        !           237:        c->min = t / 60;
        !           238:        c->sec = t % 60;
        !           239: }
        !           240: #endif

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