diff options
| author | Michael K. Johnson <johnsonm@rpath.com> | 2009-03-27 13:14:41 -0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-03-28 12:45:39 -0700 |
| commit | 01522df346f846906eaf6ca57148641476209909 (patch) | |
| tree | 06fa393052f7f0a033dcc95440788b05c4044ea2 /arch/x86 | |
| parent | c8608d6b58981a58ca4aee8308576666c5f7ab0c (diff) | |
x86, setup: mark %esi as clobbered in E820 BIOS call
Jordan Hargrave diagnosed a BIOS clobbering %esi in the E820 call.
That particular BIOS has been fixed, but there is a possibility that
this is responsible for other occasional reports of early boot
failure, and it does not hurt to add %esi to the clobbers.
-stable candidate patch.
Cc: Justin Forbes <jmforbes@linuxtx.org>
Signed-off-by: Michael K Johnson <johnsonm@rpath.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/boot/memory.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/boot/memory.c b/arch/x86/boot/memory.c index 8c3c25f3557..a99dbbe77a0 100644 --- a/arch/x86/boot/memory.c +++ b/arch/x86/boot/memory.c @@ -27,13 +27,14 @@ static int detect_memory_e820(void) do { size = sizeof(struct e820entry); - /* Important: %edx is clobbered by some BIOSes, - so it must be either used for the error output + /* Important: %edx and %esi are clobbered by some BIOSes, + so they must be either used for the error output or explicitly marked clobbered. */ asm("int $0x15; setc %0" : "=d" (err), "+b" (next), "=a" (id), "+c" (size), "=m" (*desc) - : "D" (desc), "d" (SMAP), "a" (0xe820)); + : "D" (desc), "d" (SMAP), "a" (0xe820) + : "esi"); /* BIOSes which terminate the chain with CF = 1 as opposed to %ebx = 0 don't always report the SMAP signature on |