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Annotation of sys/arch/i386/stand/libsa/time.c, Revision 1.1

1.1     ! nbrk        1: /*     $OpenBSD: time.c,v 1.16 2004/08/17 15:11:31 tom Exp $   */
        !             2:
        !             3: /*
        !             4:  * Copyright (c) 1997 Michael Shalayeff
        !             5:  * Copyright (c) 1997 Tobias Weingartner
        !             6:  * All rights reserved.
        !             7:  *
        !             8:  * Redistribution and use in source and binary forms, with or without
        !             9:  * modification, are permitted provided that the following conditions
        !            10:  * are met:
        !            11:  * 1. Redistributions of source code must retain the above copyright
        !            12:  *    notice, this list of conditions and the following disclaimer.
        !            13:  * 2. Redistributions in binary form must reproduce the above copyright
        !            14:  *    notice, this list of conditions and the following disclaimer in the
        !            15:  *    documentation and/or other materials provided with the distribution.
        !            16:  *
        !            17:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
        !            18:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
        !            19:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
        !            20:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
        !            21:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        !            22:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
        !            23:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            24:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        !            25:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        !            26:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        !            27:  * SUCH DAMAGE.
        !            28:  *
        !            29:  */
        !            30:
        !            31: #include <sys/time.h>
        !            32: #include <machine/biosvar.h>
        !            33: #include <machine/pio.h>
        !            34: #include "libsa.h"
        !            35: #include "biosdev.h"
        !            36:
        !            37: #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
        !            38:
        !            39: /*
        !            40:  * Convert from bcd (packed) to int
        !            41:  */
        !            42: static __inline u_int8_t
        !            43: bcdtoint(u_int8_t c)
        !            44: {
        !            45:
        !            46:        return ((c & 0xf0) / 8) * 5 + (c & 0x0f);
        !            47: }
        !            48:
        !            49: /*
        !            50:  * Quick compute of time in seconds since the Epoch
        !            51:  */
        !            52: const u_short monthcount[] = {
        !            53:        0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365
        !            54: };
        !            55:
        !            56: static __inline time_t
        !            57: compute(int year, u_int8_t month, u_int8_t day, u_int8_t hour,
        !            58:     u_int8_t min, u_int8_t sec)
        !            59: {
        !            60:        /* Number of days per month */
        !            61:        register time_t tt;
        !            62:
        !            63:        /* Compute days */
        !            64:        tt = (year - 1970) * 365 + monthcount[month] + day - 1;
        !            65:
        !            66:        /* Compute for leap year */
        !            67:        for (month <= 2 ? year-- : 0; year >= 1970; year--)
        !            68:                if (isleap(year))
        !            69:                        tt++;
        !            70:
        !            71:        /* Plus the time */
        !            72:        tt = sec + 60 * (min + 60 * (tt * 24 + hour));
        !            73:
        !            74:        return tt;
        !            75: }
        !            76:
        !            77: static int
        !            78: bios_time_date(int f, u_int8_t *b)
        !            79: {
        !            80:        __asm __volatile(DOINT(0x1a) "\n\t"
        !            81:            "setc %b0\n\t"
        !            82:            "movb %%ch, 0(%2)\n\t"
        !            83:            "movb %%cl, 1(%2)\n\t"
        !            84:            "movb %%dh, 2(%2)\n\t"
        !            85:            "movb %%dl, 3(%2)\n\t"
        !            86:            : "=a" (f)
        !            87:            : "0" (f), "p" (b) : "%ecx", "%edx", "cc");
        !            88:        if (f & 0xff)
        !            89:                return -1;
        !            90:        else {
        !            91:                b[0] = bcdtoint(b[0]);
        !            92:                b[1] = bcdtoint(b[1]);
        !            93:                b[2] = bcdtoint(b[2]);
        !            94:                b[3] = bcdtoint(b[3]);
        !            95:                return 0;
        !            96:        }
        !            97: }
        !            98:
        !            99: static __inline int
        !           100: biosdate(u_int8_t *b)
        !           101: {
        !           102:        return bios_time_date(4 << 8, b);
        !           103: }
        !           104:
        !           105: static __inline int
        !           106: biostime(u_int8_t *b)
        !           107: {
        !           108:        return bios_time_date(2 << 8, b);
        !           109: }
        !           110:
        !           111: /*
        !           112:  * Return time since epoch
        !           113:  */
        !           114: time_t
        !           115: getsecs(void)
        !           116: {
        !           117:        u_int8_t timebuf[4], datebuf[4];
        !           118:
        !           119:        /* Query BIOS for time & date */
        !           120:        if (!biostime(timebuf) && !biosdate(datebuf)) {
        !           121: #ifdef notdef
        !           122:                int dst;
        !           123:
        !           124:                dst = timebuf[3];
        !           125: #endif
        !           126:                /* Convert to seconds since Epoch */
        !           127:                return (compute(datebuf[0] * 100 + datebuf[1],
        !           128:                    datebuf[2], datebuf[3],
        !           129:                    timebuf[0], timebuf[1], timebuf[2]));
        !           130:        } else
        !           131:                errno = EIO;
        !           132:
        !           133:        return 1;
        !           134: }
        !           135:
        !           136: u_int
        !           137: sleep(u_int i)
        !           138: {
        !           139:        register time_t t;
        !           140:
        !           141:        /*
        !           142:         * Loop for the requested number of seconds, polling BIOS,
        !           143:         * so that it may handle interrupts.
        !           144:         */
        !           145:        for (t = getsecs() + i; getsecs() < t; cnischar());
        !           146:
        !           147:        return 0;
        !           148: }