freebsd-dev/sys/boot/i386/libi386/time.c
Mike Smith 627249c7b1 Substantially revamp the way that we determine the amount of memory available
for our use.  Use the same search order for BIOS memory size functions
as the kernel will later use.

Allow the loader to use all of the detected physical memory (this will
greatly help people trying to load enormous memory disk images).

More correctly handle running out of memory when loading an object.

Use the end of base memory for the top of the heap, rather than
blindly hoping that there is 384k left.

Add copyrights to a couple of files I forgot.
1999-12-29 09:54:46 +00:00

81 lines
2.4 KiB
C

/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <stand.h>
#include <btxv86.h>
/*
* Return the time in seconds since the beginning of the day.
*
* If we pass midnight, don't wrap back to 0.
*
* XXX uses undocumented BCD support from libstand.
*/
time_t
time(time_t *t)
{
static time_t lasttime, now;
int hr, min, sec;
v86.ctl = 0;
v86.addr = 0x1a; /* int 0x1a, function 2 */
v86.eax = 0x0200;
v86int();
hr = bcd2bin((v86.ecx & 0xff00) >> 8); /* hour in %ch */
min = bcd2bin(v86.ecx & 0xff); /* minute in %cl */
sec = bcd2bin((v86.edx & 0xff00) >> 8); /* second in %dh */
now = hr * 3600 + min * 60 + sec;
if (now < lasttime)
now += 24 * 3600;
lasttime = now;
if (t != NULL)
*t = now;
return(now);
}
/*
* Use the BIOS Wait function to pause for (period) microseconds.
*
* Resolution of this function is variable, but typically around
* 1ms.
*/
void
delay(int period)
{
v86.ctl = 0;
v86.addr = 0x15; /* int 0x15, function 0x86 */
v86.eax = 0x8600;
v86.ecx = period >> 16;
v86.edx = period & 0xffff;
v86int();
}