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: }
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