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| author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-18 12:13:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-18 12:13:02 -0700 |
| commit | 97405fe26b2a4df7090884b086ee8224ace2a6d1 (patch) | |
| tree | 528f9f1f3f8cf0ce933a366f137faaf55ab89079 /arch/i386/boot/video.h | |
| parent | a10d9a71bafd3a283da240d2868e71346d2aef6f (diff) | |
| parent | 3fbc54165d7217abf62b871c0dd074e76ce0eb31 (diff) | |
| download | linux-97405fe26b2a4df7090884b086ee8224ace2a6d1.tar.gz linux-97405fe26b2a4df7090884b086ee8224ace2a6d1.tar.bz2 linux-97405fe26b2a4df7090884b086ee8224ace2a6d1.zip | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-2.6-x86setup
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-2.6-x86setup:
[PATCH] x86: do not recompile boot for each build
[x86 setup] Save/restore DS around invocations of INT 10h
[x86 setup] VGA: Clear the Protect bit before setting the vertical height
[x86 setup] Fix assembly constraints
[x86 setup] build/tools.c: fix comment
[x86 setup] MAINTAINERS: document x86 setup code git tree
Diffstat (limited to 'arch/i386/boot/video.h')
| -rw-r--r-- | arch/i386/boot/video.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/i386/boot/video.h b/arch/i386/boot/video.h index 29eca1710b2c..b92447d51213 100644 --- a/arch/i386/boot/video.h +++ b/arch/i386/boot/video.h @@ -117,8 +117,15 @@ extern int graphic_mode; /* Graphics mode with linear frame buffer */ * int $0x10 is notorious for touching registers it shouldn't. * gcc doesn't like %ebp being clobbered, so define it as a push/pop * sequence here. + * + * A number of systems, including the original PC can clobber %bp in + * certain circumstances, like when scrolling. There exists at least + * one Trident video card which could clobber DS under a set of + * circumstances that we are unlikely to encounter (scrolling when + * using an extended graphics mode of more than 800x600 pixels), but + * it's cheap insurance to deal with that here. */ -#define INT10 "pushl %%ebp; int $0x10; popl %%ebp" +#define INT10 "pushl %%ebp; pushw %%ds; int $0x10; popw %%ds; popl %%ebp" /* Accessing VGA indexed registers */ static inline u8 in_idx(u16 port, u8 index) |