diff options
| -rw-r--r-- | src/arch/x86/interface/pcbios/int13con.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/src/arch/x86/interface/pcbios/int13con.c b/src/arch/x86/interface/pcbios/int13con.c index 2414c690..8106cd15 100644 --- a/src/arch/x86/interface/pcbios/int13con.c +++ b/src/arch/x86/interface/pcbios/int13con.c @@ -62,6 +62,10 @@ struct int13con_header { /** Log partition magic signature */ #define INT13CON_MAGIC "iPXE LOG\n\n" +/** Original INT13 vector */ +static struct segoff __bss16 ( int13con_vector ); +#define int13con_vector __use_data16 ( int13con_vector ) + /** Sector buffer */ static uint8_t __bss16_array ( int13con_buffer, [INT13_BLKSIZE] ); #define int13con_buffer __use_data16 ( int13con_buffer ) @@ -101,8 +105,13 @@ static int int13con_rw ( unsigned int op, uint64_t lba ) { int13con_address.buffer.offset = __from_data16 ( int13con_buffer ); int13con_address.lba = lba; - /* Issue INT13 */ - __asm__ ( REAL_CODE ( "int $0x13\n\t" ) + /* Emulate INT13 via original vector. We do this since iPXE + * (or another subsequent bootloader) may hook INT13 and remap + * drive numbers. + */ + __asm__ ( REAL_CODE ( "pushfw\n\t" + "cli\n\t" + "lcall *int13con_vector\n\t" ) : "=a" ( error ) : "0" ( op << 8 ), "d" ( INT13CON_DRIVE ), "S" ( __from_data16 ( &int13con_address ) ) ); @@ -261,6 +270,12 @@ static void int13con_init ( void ) { return; } + /* Store original INT13 vector */ + copy_from_real ( &int13con_vector, 0, ( 0x13 * 4 ), + sizeof ( int13con_vector ) ); + DBG ( "INT13CON using original INT13 vector %04x:%04x\n", + int13con_vector.segment, int13con_vector.offset ); + /* Locate log partition */ if ( ( rc = int13con_find() ) != 0) return; |