2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/boot/pc98/libpc98/time.c,v 1.3.2.1 2000/12/30 12:01:06 nyan Exp $
27 * $DragonFly: src/sys/boot/pc98/libpc98/Attic/time.c,v 1.2 2003/06/17 04:28:18 dillon Exp $
33 #include <machine/cpufunc.h>
35 #include "bootstrap.h"
39 * Return the time in seconds since the beginning of the day.
41 * If we pass midnight, don't wrap back to 0.
43 * XXX uses undocumented BCD support from libstand.
49 static time_t lasttime, now;
53 unsigned char bios_time[6];
58 v86.addr = 0x1c; /* int 0x1c, function 0 */
60 v86.es = VTOPSEG(bios_time);
61 v86.ebx = VTOPOFF(bios_time);
63 v86.addr = 0x1a; /* int 0x1a, function 2 */
69 hr = bcd2bin(bios_time[3]);
70 minute = bcd2bin(bios_time[4]);
71 sec = bcd2bin(bios_time[5]);
73 hr = bcd2bin((v86.ecx & 0xff00) >> 8); /* hour in %ch */
74 minute = bcd2bin(v86.ecx & 0xff); /* minute in %cl */
75 sec = bcd2bin((v86.edx & 0xff00) >> 8); /* second in %dh */
78 now = hr * 3600 + minute * 60 + sec;
89 * Use the BIOS Wait function to pause for (period) microseconds.
91 * Resolution of this function is variable, but typically around
99 period = (period + 500) / 1000;
100 for( ; period != 0 ; period--)
101 for(i=800;i != 0; i--)
102 outb(0x5f,0); /* wait 600ns */
105 v86.addr = 0x15; /* int 0x15, function 0x86 */
107 v86.ecx = period >> 16;
108 v86.edx = period & 0xffff;