Commit 1a13286b authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

[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: default avatarH. Peter Anvin <hpa@zytor.com>
parent 1514ab09

arch/i386/boot/apm.c

+3 −2
Original line number Diff line number Diff line
@@ -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;