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Added more verbose memory-map debugging.
Added redundant call to get_memmap() in int13_boot() immediately
before jumping to boot sector, to assist in debugging.
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Michael Brown committed Sep 21, 2007
1 parent 44461b1 commit 0979e67
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Showing 2 changed files with 43 additions and 11 deletions.
45 changes: 34 additions & 11 deletions src/arch/i386/firmware/pcbios/memmap.c
Expand Up @@ -74,16 +74,19 @@ static unsigned int extmemsize_e801 ( void ) {
"=d" ( confmem_16m_plus_64k )
: "a" ( 0xe801 ) );

if ( flags & CF )
if ( flags & CF ) {
DBG ( "INT 15,e801 failed with CF set\n" );
return 0;
}

if ( ! ( extmem_1m_to_16m_k | extmem_16m_plus_64k ) ) {
DBG ( "INT 15,e801 extmem=0, using confmem\n" );
extmem_1m_to_16m_k = confmem_1m_to_16m_k;
extmem_16m_plus_64k = confmem_16m_plus_64k;
}

extmem = ( extmem_1m_to_16m_k + ( extmem_16m_plus_64k * 64 ) );
DBG ( "Extended memory size %d+64*%d=%d kB\n",
DBG ( "INT 15,e801 extended memory size %d+64*%d=%d kB\n",
extmem_1m_to_16m_k, extmem_16m_plus_64k, extmem );
return extmem;
}
Expand All @@ -100,7 +103,7 @@ static unsigned int extmemsize_88 ( void ) {
__asm__ __volatile__ ( REAL_CODE ( "int $0x15" )
: "=a" ( extmem ) : "a" ( 0x8800 ) );

DBG ( "Extended memory size %d kB\n", extmem );
DBG ( "INT 15,88 extended memory size %d kB\n", extmem );
return extmem;
}

Expand Down Expand Up @@ -149,24 +152,38 @@ static int meme820 ( struct memory_map *memmap ) {
"d" ( SMAP )
: "memory" );

if ( smap != SMAP )
if ( smap != SMAP ) {
DBG ( "INT 15,e820 failed SMAP signature check\n" );
return -ENOTSUP;
}

if ( flags & CF )
if ( flags & CF ) {
DBG ( "INT 15,e820 terminated on CF set\n" );
break;
}

DBG ( "E820 region [%llx,%llx) type %d\n", e820buf.start,
( e820buf.start + e820buf.len ), ( int ) e820buf.type );
DBG ( "INT 15,e820 region [%llx,%llx) type %d\n",
e820buf.start, ( e820buf.start + e820buf.len ),
( int ) e820buf.type );
if ( e820buf.type != E820_TYPE_RAM )
continue;

region->start = e820buf.start;
region->end = e820buf.start + e820buf.len;
region++;
memmap->count++;
} while ( ( next != 0 ) &&
( memmap->count < ( sizeof ( memmap->regions ) /
sizeof ( memmap->regions[0] ) ) ) );

if ( memmap->count >= ( sizeof ( memmap->regions ) /
sizeof ( memmap->regions[0] ) ) ) {
DBG ( "INT 15,e820 too many regions returned\n" );
/* Not a fatal error; what we've got so far at
* least represents valid regions of memory,
* even if we couldn't get them all.
*/
break;
}
} while ( next != 0 );

return 0;
}

Expand All @@ -179,18 +196,24 @@ void get_memmap ( struct memory_map *memmap ) {
unsigned int basemem, extmem;
int rc;

DBG ( "Fetching system memory map\n" );

/* Clear memory map */
memset ( memmap, 0, sizeof ( *memmap ) );

/* Get base and extended memory sizes */
basemem = basememsize();
DBG ( "FBMS base memory size %d kB\n", basemem );
extmem = extmemsize();

/* Try INT 15,e820 first */
if ( ( rc = meme820 ( memmap ) ) == 0 )
if ( ( rc = meme820 ( memmap ) ) == 0 ) {
DBG ( "Obtained system memory map via INT 15,e820\n" );
return;
}

/* Fall back to constructing a map from basemem and extmem sizes */
DBG ( "INT 15,e820 failed; constructing map\n" );
memmap->regions[0].end = ( basemem * 1024 );
memmap->regions[1].start = 0x100000;
memmap->regions[1].end = 0x100000 + ( extmem * 1024 );
Expand Down
9 changes: 9 additions & 0 deletions src/arch/i386/interface/pcbios/int13.c
Expand Up @@ -23,6 +23,7 @@
#include <assert.h>
#include <gpxe/list.h>
#include <gpxe/blockdev.h>
#include <gpxe/memmap.h>
#include <realmode.h>
#include <bios.h>
#include <biosint.h>
Expand Down Expand Up @@ -601,6 +602,7 @@ void unregister_int13_drive ( struct int13_drive *drive ) {
* Note that this function can never return success, by definition.
*/
int int13_boot ( unsigned int drive ) {
struct memory_map memmap;
int status, signature;
int discard_c, discard_d;
int rc;
Expand Down Expand Up @@ -634,6 +636,13 @@ int int13_boot ( unsigned int drive ) {
return -ENOEXEC;
}

/* Dump out memory map prior to boot, if memmap debugging is
* enabled. Not required for program flow, but we have so
* many problems that turn out to be memory-map related that
* it's worth doing.
*/
get_memmap ( &memmap );

/* Jump to boot sector */
if ( ( rc = call_bootsector ( 0x0, 0x7c00, drive ) ) != 0 ) {
DBG ( "INT 13 drive %02x boot returned\n", drive );
Expand Down

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