From 1a13286b104faeeb4f4bc3bfbf4d4fcdcd2569ed Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 23 Jul 2007 15:37:14 -0700 Subject: [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 --- arch/i386/boot/apm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/i386/boot') diff --git a/arch/i386/boot/apm.c b/arch/i386/boot/apm.c index 8be3f5686af..eab50c55a3a 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; -- cgit v1.2.3-70-g09d2