x86, setup: "glove box" BIOS interrupts in the video code
Impact: BIOS proofing
"Glove box" off BIOS interrupts in the video code.
LKML-Reference: <49DE7F79.4030106@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/arch/x86/boot/video-bios.c b/arch/x86/boot/video-bios.c
index 3fa979c..d660be4 100644
--- a/arch/x86/boot/video-bios.c
+++ b/arch/x86/boot/video-bios.c
@@ -2,6 +2,7 @@
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
+ * Copyright 2009 Intel Corporation; author H. Peter Anvin
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
@@ -29,21 +30,21 @@
static int set_bios_mode(u8 mode)
{
- u16 ax;
+ struct biosregs ireg, oreg;
u8 new_mode;
- ax = mode; /* AH=0x00 Set Video Mode */
- asm volatile(INT10
- : "+a" (ax)
- : : "ebx", "ecx", "edx", "esi", "edi");
+ initregs(&ireg);
+ ireg.al = mode; /* AH=0x00 Set Video Mode */
+ intcall(0x10, &ireg, NULL);
- ax = 0x0f00; /* Get Current Video Mode */
- asm volatile(INT10
- : "+a" (ax)
- : : "ebx", "ecx", "edx", "esi", "edi");
+
+ ireg.ah = 0x0f; /* Get Current Video Mode */
+ intcall(0x10, &ireg, &oreg);
do_restore = 1; /* Assume video contents were lost */
- new_mode = ax & 0x7f; /* Not all BIOSes are clean with the top bit */
+
+ /* Not all BIOSes are clean with the top bit */
+ new_mode = ireg.al & 0x7f;
if (new_mode == mode)
return 0; /* Mode change OK */
@@ -53,10 +54,8 @@
/* Mode setting failed, but we didn't end up where we
started. That's bad. Try to revert to the original
video mode. */
- ax = boot_params.screen_info.orig_video_mode;
- asm volatile(INT10
- : "+a" (ax)
- : : "ebx", "ecx", "edx", "esi", "edi");
+ ireg.ax = boot_params.screen_info.orig_video_mode;
+ intcall(0x10, &ireg, NULL);
}
#endif
return -1;