/*-
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Obtain memory configuration information from the BIOS
*/
#include <stand.h>
#include "libi386.h"
#include "btxv86.h"
vm_offset_t memtop, memtop_copyin, high_heap_base;
uint32_t bios_basemem, bios_extmem, high_heap_size;
/*
* The minimum amount of memory to reserve in bios_extmem for the heap.
*/
#define HEAP_MIN (3 * 1024 * 1024)
void
bios_getmem(void)
{
bios_basemem = ((*(u_char *)PTOV(0xA1501) & 0x07) + 1) * 128 * 1024;
bios_extmem = *(u_char *)PTOV(0xA1401) * 128 * 1024 +
*(u_int16_t *)PTOV(0xA1594) * 1024 * 1024;
/* Set memtop to actual top of memory */
memtop = memtop_copyin = 0x100000 + bios_extmem;
/*
* If we have extended memory, use the last 3MB of 'extended' memory
* as a high heap candidate.
*/
if (bios_extmem >= HEAP_MIN) {
high_heap_size = HEAP_MIN;
high_heap_base = memtop - HEAP_MIN;
}
}
