1/*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include <stand.h> 31#include <btxv86.h> 32#include <machine/cpufunc.h> 33#include "bootstrap.h" 34#include "libi386.h" 35 36static int bios_seconds(void); 37 38/* 39 * Return the BIOS time-of-day value. 40 * 41 * XXX uses undocumented BCD support from libstand. 42 */ 43static int 44bios_seconds(void) 45{ 46 int hr, minute, sec; 47 unsigned char bios_time[6]; 48 49 v86.ctl = 0; 50 v86.addr = 0x1c; /* int 0x1c, function 0 */ 51 v86.eax = 0x0000; 52 v86.es = VTOPSEG(bios_time); 53 v86.ebx = VTOPOFF(bios_time); 54 v86int(); 55 56 hr = bcd2bin(bios_time[3]); 57 minute = bcd2bin(bios_time[4]); 58 sec = bcd2bin(bios_time[5]); 59 60 return (hr * 3600 + minute * 60 + sec); 61} 62 63/* 64 * Return the time in seconds since the beginning of the day. 65 */ 66time_t 67time(time_t *t) 68{ 69 static time_t lasttime; 70 time_t now; 71 72 now = bios_seconds(); 73 74 if (now < lasttime) 75 now += 24 * 3600; 76 lasttime = now; 77 78 if (t != NULL) 79 *t = now; 80 return(now); 81} 82 83/* 84 * Use the BIOS Wait function to pause for (period) microseconds. 85 * 86 * Resolution of this function is variable, but typically around 87 * 1ms. 88 */ 89void 90delay(int period) 91{ 92 int i; 93 94 period = (period + 500) / 1000; 95 for( ; period != 0 ; period--) 96 for(i=800;i != 0; i--) 97 outb(0x5f,0); /* wait 600ns */ 98} 99