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 }