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path: root/src/devices/oprom/x86_asm.S
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Diffstat (limited to 'src/devices/oprom/x86_asm.S')
-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