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#ifdef PCBIOS
#include "etherboot.h"
#include "realmode.h"
#define CF ( 1 << 0 )
#ifndef MEMSIZES_DEBUG
#define MEMSIZES_DEBUG 0
#endif
/* by Eric Biederman */
struct meminfo meminfo;
/**************************************************************************
BASEMEMSIZE - Get size of the conventional (base) memory
**************************************************************************/
unsigned short basememsize ( void )
{
RM_FRAGMENT(rm_basememsize,
"int $0x12\n\t"
);
return real_call ( rm_basememsize, NULL, NULL );
}
/**************************************************************************
MEMSIZE - Determine size of extended memory
**************************************************************************/
unsigned int memsize ( void )
{
struct {
reg16_t ax;
} PACKED in_stack;
struct {
reg16_t ax;
reg16_t bx;
reg16_t cx;
reg16_t dx;
reg16_t flags;
} PACKED out_stack;
int memsize;
RM_FRAGMENT(rm_memsize,
/* Some buggy BIOSes don't clear/set carry on pass/error of
* e801h memory size call or merely pass cx,dx through without
* changing them, so we set carry and zero cx,dx before call.
*/
"stc\n\t"
"xorw %cx,%cx\n\t"
"xorw %dx,%dx\n\t"
"popw %ax\n\t"
"int $0x15\n\t"
"pushfw\n\t"
"pushw %dx\n\t"
"pushw %cx\n\t"
"pushw %bx\n\t"
"pushw %ax\n\t"
);
/* Try INT 15,e801 first */
in_stack.ax.word = 0xe801;
real_call ( rm_memsize, &in_stack, &out_stack );
if ( out_stack.flags.word & CF ) {
/* INT 15,e801 not supported: try INT 15,88 */
in_stack.ax.word = 0x8800;
memsize = real_call ( rm_memsize, &in_stack, &out_stack );
} else {
/* Some BIOSes report extended memory via ax,bx rather
* than cx,dx
*/
if ( (out_stack.cx.word==0) && (out_stack.dx.word==0) ) {
/* Use ax,bx */
memsize = ( out_stack.bx.word<<6 ) + out_stack.ax.word;
} else {
/* Use cx,dx */
memsize = ( out_stack.dx.word<<6 ) + out_stack.cx.word;
}
}
return memsize;
}
#define SMAP ( 0x534d4150 )
int meme820 ( struct e820entry *buf, int count )
{
struct {
reg16_t flags;
reg32_t eax;
reg32_t ebx;
struct e820entry entry;
} PACKED stack;
int index = 0;
RM_FRAGMENT(rm_meme820,
"addw $6, %sp\n\t" /* skip flags, eax */
"popl %ebx\n\t"
"pushw %ss\n\t" /* es:di = ss:sp */
"popw %es\n\t"
"movw %sp, %di\n\t"
"movl $0xe820, %eax\n\t"
"movl $" RM_STR(SMAP) ", %edx\n\t"
"movl $" RM_STR(E820ENTRY_SIZE) ", %ecx\n\t"
"int $0x15\n\t"
"pushl %ebx\n\t"
"pushl %eax\n\t"
"pushfw\n\t"
);
stack.ebx.dword = 0; /* 'EOF' marker */
while ( ( index < count ) &&
( ( index == 0 ) || ( stack.ebx.dword != 0 ) ) ) {
real_call ( rm_meme820, &stack, &stack );
if ( stack.eax.dword != SMAP ) return 0;
if ( stack.flags.word & CF ) return 0;
buf[index++] = stack.entry;
}
return index;
}
void get_memsizes(void)
{
/* Ensure we don't stomp bios data structutres.
* the interrupt table: 0x000 - 0x3ff
* the bios data area: 0x400 - 0x502
* Dos variables: 0x502 - 0x5ff
*/
static const unsigned min_addr = 0x600;
unsigned i;
unsigned basemem;
basemem = get_free_base_memory();
meminfo.basememsize = basememsize();
meminfo.memsize = memsize();
#ifndef IGNORE_E820_MAP
meminfo.map_count = meme820(meminfo.map, E820MAX);
#else
meminfo.map_count = 0;
#endif
if (meminfo.map_count == 0) {
/* If we don't have an e820 memory map fake it */
meminfo.map_count = 2;
meminfo.map[0].addr = 0;
meminfo.map[0].size = meminfo.basememsize << 10;
meminfo.map[0].type = E820_RAM;
meminfo.map[1].addr = 1024*1024;
meminfo.map[1].size = meminfo.memsize << 10;
meminfo.map[1].type = E820_RAM;
}
/* Scrub the e820 map */
for(i = 0; i < meminfo.map_count; i++) {
if (meminfo.map[i].type != E820_RAM) {
continue;
}
/* Reserve the bios data structures */
if (meminfo.map[i].addr < min_addr) {
unsigned long delta;
delta = min_addr - meminfo.map[i].addr;
if (delta > meminfo.map[i].size) {
delta = meminfo.map[i].size;
}
meminfo.map[i].addr = min_addr;
meminfo.map[i].size -= delta;
}
/* Ensure the returned e820 map is in sync
* with the actual memory state
*/
if ((meminfo.map[i].addr < 0xa0000) &&
((meminfo.map[i].addr + meminfo.map[i].size) > basemem))
{
if (meminfo.map[i].addr <= basemem) {
meminfo.map[i].size = basemem - meminfo.map[i].addr;
} else {
meminfo.map[i].addr = basemem;
meminfo.map[i].size = 0;
}
}
}
#if MEMSIZES_DEBUG
{
int i;
printf("basememsize %d\n", meminfo.basememsize);
printf("memsize %d\n", meminfo.memsize);
printf("Memory regions(%d):\n", meminfo.map_count);
for(i = 0; i < meminfo.map_count; i++) {
unsigned long long r_start, r_end;
r_start = meminfo.map[i].addr;
r_end = r_start + meminfo.map[i].size;
printf("[%X%X, %X%X) type %d\n",
(unsigned long)(r_start >> 32),
(unsigned long)r_start,
(unsigned long)(r_end >> 32),
(unsigned long)r_end,
meminfo.map[i].type);
#if defined(CONSOLE_FIRMWARE)
sleep(1); /* No way to see 32 entries on a standard 80x25 screen... */
#endif
}
}
#endif
}
#endif /* PCBIOS */
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