summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/devices/oprom/x86_asm.S65
1 files changed, 37 insertions, 28 deletions
diff --git a/src/devices/oprom/x86_asm.S b/src/devices/oprom/x86_asm.S
index 488bfa6b91..56ebb3a885 100644
--- a/src/devices/oprom/x86_asm.S
+++ b/src/devices/oprom/x86_asm.S
@@ -75,35 +75,36 @@ __buffer = RELOCATED(.)
.globl __realmode_call
__realmode_call = RELOCATED(.)
/* save all registers to the stack */
- pushal
+ pusha
+ pushf
- /* Move the protected mode stack to a safe place */
+ /* Move the protected mode stack pointer to a safe place */
movl %esp, __stack
- movl %esp, %ebp
+ movl %esp, %ebp
- /* This function is called with regparm=0 and we have
- * to skip the 32 byte from pushal. Hence start at 36.
+ /* This function is called with regparm=0 and we have to
+ * skip the 36 byte from pushf+pusha. Hence start at 40.
*/
/* entry point */
- movl 36(%ebp), %eax
+ movl 40(%ebp), %eax
mov %ax, __lcall_instr + 1
andl $0xffff0000, %eax
shrl $4, %eax
mov %ax, __lcall_instr + 3
/* initial register values */
- movl 40(%ebp), %eax
- movl %eax, __registers + 0 /* eax */
movl 44(%ebp), %eax
- movl %eax, __registers + 4 /* ebx */
+ movl %eax, __registers + 0 /* eax */
movl 48(%ebp), %eax
- movl %eax, __registers + 8 /* ecx */
+ movl %eax, __registers + 4 /* ebx */
movl 52(%ebp), %eax
- movl %eax, __registers + 12 /* edx */
+ movl %eax, __registers + 8 /* ecx */
movl 56(%ebp), %eax
- movl %eax, __registers + 16 /* esi */
+ movl %eax, __registers + 12 /* edx */
movl 60(%ebp), %eax
+ movl %eax, __registers + 16 /* esi */
+ movl 64(%ebp), %eax
movl %eax, __registers + 20 /* edi */
/* Activate the right segment descriptor real mode. */
@@ -193,41 +194,45 @@ __lcall_instr = RELOCATED(.)
/* restore proper idt */
lidt idtarg
- /* and exit */
+ /* restore stack pointer, eflags and register values */
movl __stack, %esp
- popal
+ popf
+ popa
+ /* and exit */
// TODO return AX from OPROM call
ret
.globl __realmode_interrupt
__realmode_interrupt = RELOCATED(.)
/* save all registers to the stack */
- pushal
- /* save the stack */
+ pusha
+ pushf
+
+ /* save the stack pointer */
movl %esp, __stack
- movl %esp, %ebp
+ movl %esp, %ebp
- /* This function is called with regparm=0 and we have
- * to skip the 32 byte from pushal. Hence start at 36.
+ /* This function is called with regparm=0 and we have to
+ * skip the 36 byte from pushf+pusha. Hence start at 40.
*/
/* prepare interrupt calling code */
- movl 36(%ebp), %eax
+ movl 40(%ebp), %eax
movb %al, __intXX_instr + 1 /* intno */
/* initial register values */
- movl 40(%ebp), %eax
- movl %eax, __registers + 0 /* eax */
movl 44(%ebp), %eax
- movl %eax, __registers + 4 /* ebx */
+ movl %eax, __registers + 0 /* eax */
movl 48(%ebp), %eax
- movl %eax, __registers + 8 /* ecx */
+ movl %eax, __registers + 4 /* ebx */
movl 52(%ebp), %eax
- movl %eax, __registers + 12 /* edx */
+ movl %eax, __registers + 8 /* ecx */
movl 56(%ebp), %eax
- movl %eax, __registers + 16 /* esi */
+ movl %eax, __registers + 12 /* edx */
movl 60(%ebp), %eax
+ movl %eax, __registers + 16 /* esi */
+ movl 64(%ebp), %eax
movl %eax, __registers + 20 /* edi */
/* This configures CS properly for real mode. */
@@ -309,9 +314,10 @@ __intXX_instr = RELOCATED(.)
/* restore coreboot's 32-bit IDT */
lidt idtarg
- /* Exit */
+ /* restore stack pointer, eflags and register values and exit */
movl __stack, %esp
- popal
+ popf
+ popa
ret
/* This is the 16-bit interrupt entry point called by the IDT stub code.
@@ -327,6 +333,9 @@ __interrupt_handler_16bit = RELOCATED(.)
push %fs
push %gs
+ /* Clear DF to not break ABI assumptions */
+ cld
+
/* Clean up the interrupt number. We could have done this in the stub,
* but it would have cost 2 more bytes per stub entry.
*/