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Annotation of sys/arch/i386/stand/libsa/time.c, Revision 1.1.1.1

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: }