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/*
* Copyright (c) 1995-1994 The University of Utah and
* the Computer Systems Laboratory at the University of Utah (CSL).
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software is hereby
* granted provided that (1) source code retains these copyright, permission,
* and disclaimer notices, and (2) redistributions including binaries
* reproduce the notices in supporting documentation, and (3) all advertising
* materials mentioning features or use of this software display the following
* acknowledgement: ``This product includes software developed by the
* Computer Systems Laboratory at the University of Utah.''
*
* THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
* IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
* ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* CSL requests users of this software to return to csl-dist@cs.utah.edu any
* improvements that they make and grant CSL redistribution rights.
*
* Author: Bryan Ford, University of Utah CSL
*/
#include <mach/machine/code16.h>
#include <mach/machine/vm_types.h>
#include <mach/machine/far_ptr.h>
#include <mach/machine/proc_reg.h>
#include "i16_bios.h"
#include "phys_mem.h"
#include "vm_param.h"
#include "debug.h"
static vm_offset_t ext_mem_phys_free_mem;
static vm_size_t ext_mem_phys_free_size;
CODE32
int ext_mem_collect(void)
{
if (ext_mem_phys_free_mem)
{
phys_mem_add(ext_mem_phys_free_mem, ext_mem_phys_free_size);
ext_mem_phys_free_mem = 0;
}
}
CODE16
void i16_ext_mem_check()
{
vm_offset_t ext_mem_top, ext_mem_bot;
unsigned short ext_mem_k;
/* Find the top of available extended memory. */
asm volatile("
int $0x15
jnc 1f
xorw %%ax,%%ax
1:
" : "=a" (ext_mem_k)
: "a" (0x8800));
ext_mem_top = 0x100000 + (vm_offset_t)ext_mem_k * 1024;
/* XXX check for >16MB memory using function 0xc7 */
ext_mem_bot = 0x100000;
/* Check for extended memory allocated bottom-up: method 1.
This uses the technique (and, loosely, the code)
described in the VCPI spec, version 1.0. */
if (ext_mem_top > ext_mem_bot)
{
asm volatile("
pushw %%es
xorw %%ax,%%ax
movw %%ax,%%es
movw %%es:0x19*4+2,%%ax
movw %%ax,%%es
movw $0x12,%%di
movw $7,%%cx
rep
cmpsb
jne 1f
xorl %%edx,%%edx
movb %%es:0x2e,%%dl
shll $16,%%edx
movw %%es:0x2c,%%dx
1:
popw %%es
" : "=d" (ext_mem_bot)
: "d" (ext_mem_bot),
"S" ((unsigned short)(vm_offset_t)"VDISK V")
: "eax", "ecx", "esi", "edi");
}
i16_assert(ext_mem_bot >= 0x100000);
/* Check for extended memory allocated bottom-up: method 2.
This uses the technique (and, loosely, the code)
described in the VCPI spec, version 1.0. */
if (ext_mem_top > ext_mem_bot)
{
struct {
char pad1[3];
char V;
long DISK;
char pad2[30-8];
unsigned short addr;
} buf;
unsigned char rc;
i16_assert(sizeof(buf) == 0x20);
rc = i16_bios_copy_ext_mem(0x100000, kvtolin((vm_offset_t)&buf), sizeof(buf)/2);
if ((rc == 0) && (buf.V == 'V') && (buf.DISK == 'DISK'))
{
vm_offset_t new_bot = (vm_offset_t)buf.addr << 10;
i16_assert(new_bot > 0x100000);
if (new_bot > ext_mem_bot)
ext_mem_bot = new_bot;
}
}
i16_assert(ext_mem_bot >= 0x100000);
if (ext_mem_top > ext_mem_bot)
{
ext_mem_phys_free_mem = ext_mem_bot;
ext_mem_phys_free_size = ext_mem_top - ext_mem_bot;
/* We need to update phys_mem_max here
instead of just letting phys_mem_add() do it
when the memory is collected with phys_mem_collect(),
because VCPI initialization needs to know the top of physical memory
before phys_mem_collect() is called.
See i16_vcpi.c for the gross details. */
if (ext_mem_top > phys_mem_max)
phys_mem_max = ext_mem_top;
}
}
void i16_ext_mem_shutdown()
{
/* We didn't actually allocate the memory,
so no need to deallocate it... */
}
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