diff options
| author | Michael Brown | 2017-01-26 10:45:19 +0100 |
|---|---|---|
| committer | Michael Brown | 2017-01-26 10:45:19 +0100 |
| commit | f8cf3ceb0bfc3e88ae32702e90b47439be0deee4 (patch) | |
| tree | 9ca1fa8dd2745aeb1903f54a05047fbcc0014139 /src/arch | |
| parent | [int13] Avoid potential division by zero (diff) | |
| download | ipxe-f8cf3ceb0bfc3e88ae32702e90b47439be0deee4.tar.gz ipxe-f8cf3ceb0bfc3e88ae32702e90b47439be0deee4.tar.xz ipxe-f8cf3ceb0bfc3e88ae32702e90b47439be0deee4.zip | |
[int13] Test correct return status from INT 13 calls
INT 13 calls return a status value via %ah, with CF set if %ah is
non-zero (indicating an error). Our wrappers zero the whole of %ax if
CF is clear, to allow C code (which has no easy access to CF) to
simply test for a non-zero status to detect an error.
The current code assigns the returned status to a uint8_t, effectively
testing %al rather than %ah. Fix by treating the returned status as a
uint16_t instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/x86/interface/pcbios/int13.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/arch/x86/interface/pcbios/int13.c b/src/arch/x86/interface/pcbios/int13.c index 8b2e134b..3e03e8c5 100644 --- a/src/arch/x86/interface/pcbios/int13.c +++ b/src/arch/x86/interface/pcbios/int13.c @@ -1751,7 +1751,7 @@ static void int13_unhook ( unsigned int drive ) { * @ret rc Return status code */ static int int13_load_mbr ( unsigned int drive, struct segoff *address ) { - uint8_t status; + uint16_t status; int discard_b, discard_c, discard_d; uint16_t magic; @@ -1775,7 +1775,7 @@ static int int13_load_mbr ( unsigned int drive, struct segoff *address ) { : "a" ( 0x0201 ), "b" ( *address ), "c" ( 1 ), "d" ( drive ) ); if ( status ) { - DBG ( "INT13 drive %02x could not read MBR (status %02x)\n", + DBG ( "INT13 drive %02x could not read MBR (status %04x)\n", drive, status ); return -EIO; } @@ -1818,7 +1818,7 @@ static int int13_load_eltorito ( unsigned int drive, struct segoff *address ) { struct eltorito_validation_entry valid; struct eltorito_boot_entry boot; } __attribute__ (( packed )) catalog; - uint8_t status; + uint16_t status; /* Use INT 13, 4d to read the boot catalog */ __asm__ __volatile__ ( REAL_CODE ( "stc\n\t" @@ -1833,7 +1833,7 @@ static int int13_load_eltorito ( unsigned int drive, struct segoff *address ) { "S" ( __from_data16 ( &eltorito_cmd ) ) ); if ( status ) { DBG ( "INT13 drive %02x could not read El Torito boot catalog " - "(status %02x)\n", drive, status ); + "(status %04x)\n", drive, status ); return -EIO; } copy_from_user ( &catalog, phys_to_user ( eltorito_cmd.buffer ), 0, @@ -1880,7 +1880,7 @@ static int int13_load_eltorito ( unsigned int drive, struct segoff *address ) { "S" ( __from_data16 ( &eltorito_address ) ) ); if ( status ) { DBG ( "INT13 drive %02x could not read El Torito boot image " - "(status %02x)\n", drive, status ); + "(status %04x)\n", drive, status ); return -EIO; } |