diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/devices/oprom/x86_asm.S | 65 |
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. */ |