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.

diff --git a/src/arch/i386/firmware/pcbios/memmap.c b/src/arch/i386/firmware/pcbios/memmap.c
index 318ba0910463c12e84c2fc8eaa6158ec2a621f03..b6a8ca3c7a490b511bb43e268bead15bec8686ed 100644 (file)
--- a/src/arch/i386/firmware/pcbios/memmap.c
+++ b/src/arch/i386/firmware/pcbios/memmap.c
@@ -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;
 }
@@ -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;
 }
 
@@ -149,14 +152,19 @@ 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;
 
@@ -164,9 +172,18 @@ static int meme820 ( struct memory_map *memmap ) {
                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;
 }
 
@@ -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 );

diff --git a/src/arch/i386/interface/pcbios/int13.c b/src/arch/i386/interface/pcbios/int13.c
index a26dcff4aa7ee23d62fbed9cfcbe3b71e8c7ecfd..7e09fb5f90d31a148eee023596486862e2186025 100644 (file)
--- a/src/arch/i386/interface/pcbios/int13.c
+++ b/src/arch/i386/interface/pcbios/int13.c
@@ -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>
@@ -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;
@@ -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 );