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authorEdwin Beasant <edwin_beasant@virtensys.com>2010-06-04 20:32:12 +0000
committerStefan Reinauer <stepan@openbios.org>2010-06-04 20:32:12 +0000
commit0c47c4d02d55eb8b7c0f467dbf2971e7a1d870e0 (patch)
tree9e8387fa1f03b79dabd153981d329afa88344cc5 /src
parent29a6a19715eb3d33f8eef0a963f71250430bb707 (diff)
downloadcoreboot-0c47c4d02d55eb8b7c0f467dbf2971e7a1d870e0.tar.xz
This patch fixes the option rom code that was buggy when it switched
segment registers before restoring register values. This was breaking the Geode VSA, and probably would have hurt other option roms as well. Signed-off-by: Edwin Beasant <edwin_beasant@virtensys.com> Acked-by: Patrick Georgi <patrick.georgi@coresystems.de> Signed-off-by: Stefan Reinauer <stepan@coresystems.de> Acked-by: Nils Jacobs <njacobs8@hetnet.nl> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5612 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src')
-rw-r--r--src/devices/oprom/x86_asm.S36
1 files changed, 21 insertions, 15 deletions
diff --git a/src/devices/oprom/x86_asm.S b/src/devices/oprom/x86_asm.S
index bbae4b1bce..e355da8fb9 100644
--- a/src/devices/oprom/x86_asm.S
+++ b/src/devices/oprom/x86_asm.S
@@ -141,20 +141,23 @@ __realmode_call = RELOCATED(.)
mov %ax, %ds
lidt __realmode_idt
- /* Set all segments to 0x0000, ds to 0x0040 */
- mov %ax, %es
- mov %ax, %fs
- mov %ax, %gs
- mov $0x40, %ax
- mov %ax, %ds
-
/* initialize registers for option rom lcall */
movl __registers + 0, %eax
movl __registers + 4, %ebx
movl __registers + 8, %ecx
movl __registers + 12, %edx
movl __registers + 16, %esi
- movl __registers + 20, %edi
+ movl __registers + 20, %edi
+
+ /* Set all segments to 0x0000, ds to 0x0040 */
+ push %ax
+ xor %ax, %ax
+ mov %ax, %es
+ mov %ax, %fs
+ mov %ax, %gs
+ mov $0x40, %ax
+ mov %ax, %ds
+ pop %ax
/* ************************************ */
__lcall_instr = RELOCATED(.)
@@ -262,12 +265,6 @@ __realmode_interrupt = RELOCATED(.)
mov %ax, %ds
lidt __realmode_idt
- /* Set all segments to 0x0000 */
- mov %ax, %ds
- mov %ax, %es
- mov %ax, %fs
- mov %ax, %gs
-
/* initialize registers for intXX call */
movl __registers + 0, %eax
movl __registers + 4, %ebx
@@ -276,6 +273,15 @@ __realmode_interrupt = RELOCATED(.)
movl __registers + 16, %esi
movl __registers + 20, %edi
+ /* Set all segments to 0x0000 */
+ push %ax
+ xor %ax, %ax
+ mov %ax, %ds
+ mov %ax, %es
+ mov %ax, %fs
+ mov %ax, %gs
+ pop %ax
+
__intXX_instr = RELOCATED(.)
.byte 0xcd, 0x00 /* This becomes intXX */
@@ -376,7 +382,7 @@ __interrupt_handler_16bit = RELOCATED(.)
mov %ax, %ds
lidt __realmode_idt
- /* Set up segment registers to segment 0x0000 */
+ /* Set up segment registers to segment 0x0000 and ds to 0x040 */
mov %ax, %es
mov %ax, %fs
mov %ax, %gs