diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2007-07-23 15:37:14 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2007-07-25 12:02:21 -0700 |
| commit | 1a13286b104faeeb4f4bc3bfbf4d4fcdcd2569ed (patch) | |
| tree | 37fef9c9676b5efe90773a8b7ba4832ae492f6ef | |
| parent | 1514ab09edb071345fe17cd230c97f9e72c9478e (diff) | |
[x86 setup] APM: BX should be zero when disconnecting
For APM calls, BX contains the device index, which is zero for
the system BIOS. Disconnect requres BX = 0.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/i386/boot/apm.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/i386/boot/apm.c b/arch/i386/boot/apm.c index 8be3f5686af6..eab50c55a3a5 100644 --- a/arch/i386/boot/apm.c +++ b/arch/i386/boot/apm.c @@ -45,9 +45,10 @@ int query_apm_bios(void) /* Disconnect first, just in case */ ax = 0x5304; + bx = 0; asm volatile("pushl %%ebp ; int $0x15 ; popl %%ebp" - : "+a" (ax) - : : "ebx", "ecx", "edx", "esi", "edi"); + : "+a" (ax), "+b" (bx) + : : "ecx", "edx", "esi", "edi"); /* Paranoia */ ebx = esi = 0; |