summaryrefslogtreecommitdiff
path: root/sys/arch/i386/stand/libsa/time.c
blob: fc02e34be3cd6f5450c09c8a7f4e0e3afebde853 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*	$OpenBSD: time.c,v 1.8 1997/08/31 07:54:18 mickey Exp $	*/

/*
 * Copyright (c) 1997 Michael Shalayeff
 * Copyright (c) 1997 Tobias Weingartner
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Tobias Weingartner.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <sys/time.h>
#include <machine/biosvar.h>
#include <machine/pio.h>
#include "libsa.h"
#include "biosdev.h"

#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)

/*
 * Convert from bcd (packed) to int
 */
static __inline u_int8_t
bcdtoint(register u_int8_t c) {

	return ((c & 0xf0) / 8) * 5 + (c & 0x0f);
}

/*
 * Quick compute of time in seconds since the Epoch
 */
static __inline time_t
compute(year, month, day, hour, min, sec)
	int year;
	u_int8_t month, day, hour, min, sec;
{
	/* Number of days per month */
	static const u_short monthcount[] = {
		0, 0, 31, 59, 90, 120, 151, 181,
		212, 243, 273, 304, 334, 365
	};
	register time_t tt;

	/* Compute days */
	tt = (year - 1970) * 365 + monthcount[month] + day;

	/* Compute for leap year */
	for(month <= 2? year--:0;year >= 1970;year--)
		if(isleap(year))
			tt++;

	/* Plus the time */
	tt = sec + 60 * (min + 60 * (tt * 24 + hour));

	return tt;
}

static int
bios_time_date(int f, register u_int8_t *b)
{
	__asm __volatile(DOINT(0x1a) "\n\t"
		       "setc %b0\n\t"
		       "movb %%ch, 0(%1)\n\t"
		       "movb %%cl, 1(%1)\n\t"
		       "movb %%dh, 2(%1)\n\t"
		       "movb %%dl, 3(%1)\n\t"
		       : "=a" (f)
		       : "0" (f), "p" (b) : "%ecx", "%edx", "cc");
	if (f & 0xff)
		return -1;
	else {
		b[0] = bcdtoint(b[0]);
		b[1] = bcdtoint(b[1]);
		b[2] = bcdtoint(b[2]);
		b[3] = bcdtoint(b[3]);
		return 0;
	}
}

static __inline int
biosdate(register u_int8_t *b)
{
	return bios_time_date(4 << 8, b);
}

static __inline int
biostime(register u_int8_t *b)
{
	return bios_time_date(2 << 8, b);
}

/*
 * Return time since epoch
 */
time_t
getsecs(void)
{
	u_int8_t timebuf[4], datebuf[4];

	/* Query BIOS for time & date */
	if(!biostime(timebuf) && !biosdate(datebuf)) {
#ifdef notdef
		int dst;

		dst = timebuf[3];
#endif
		/* Convert to seconds since Epoch */
		return compute(datebuf[0] * 100 + datebuf[1],
			       datebuf[2], datebuf[3],
			       timebuf[0], timebuf[1], timebuf[2]);
	} else
		errno = EIO;

	return(1);
}

/*
 * Return time since epoch
 */
void
time_print(void)
{
	u_int8_t timebuf[4], datebuf[4];

	/* Query BIOS for time & date */
	if(!biostime(timebuf) && !biosdate(datebuf)) {
#ifdef notdef
		int dst;

		dst = timebuf[3];
#endif
		/* Convert to sane values */
		printf("%d/%d/%d - %d:%d:%d\n",
		       datebuf[3], datebuf[2], datebuf[0] * 100 + datebuf[1],
		       timebuf[0], timebuf[1], timebuf[2]);
	} else
		printf("no idea (in BIOS)\n");

	return;
}

u_int
sleep(i)
	u_int i;
{
	register time_t t;

	/* loop for that number of seconds, polling BIOS,
	   so that it may handle interrupts */
	for (t = getsecs() + i; getsecs() < t; cnischar());

	return 0;
}