diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/i386/transitions/liba20.S | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/arch/i386/transitions/liba20.S b/src/arch/i386/transitions/liba20.S index 594d6201..a60f1a54 100644 --- a/src/arch/i386/transitions/liba20.S +++ b/src/arch/i386/transitions/liba20.S @@ -96,8 +96,11 @@ test_a20_long: .section ".text16.early", "awx", @progbits .code16 enable_a20_bios: - /* Preserve registers */ - pushw %ax + + /* Preserve registers. Be very paranoid, since some BIOSes + * are reported to clobber %ebx + */ + pushal /* Attempt INT 15,2401 */ movw $0x2401, %ax @@ -108,7 +111,7 @@ enable_a20_bios: call test_a20_short 99: /* Restore registers and return */ - popw %ax + popal ret .size enable_a20_bios, . - enable_a20_bios |