blob: 35747b7466de46d38c798249c01d2379f342a34d [file] [log] [blame]
// Rom layout and bios assembler to C interface.
//
// Copyright (C) 2009-2013 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "asm-offsets.h" // BREGS_*
#include "config.h" // CONFIG_*
#include "entryfuncs.S" // ENTRY_*
/****************************************************************
* Rom Header
****************************************************************/
.section .rom.header
.code16gcc
.global _rom_header, _rom_header_size, _rom_header_checksum
_rom_header:
.word 0xaa55
_rom_header_size:
.byte 0
_rom_header_entry:
jmp _optionrom_entry
_rom_header_checksum:
.byte 0
_rom_header_other:
.space 17
_rom_header_pcidata:
#if CONFIG_VGA_PCI == 1
.word rom_pci_data
#else
.word 0
#endif
_rom_header_pnpdata:
.word 0
_rom_header_other2:
.word 0
_rom_header_signature:
.asciz "IBM"
/****************************************************************
* Entry points
****************************************************************/
// This macro is the same as ENTRY_ARG except the "calll"
// instruction is avoided to work around known issues in the
// emulation of some versions of x86emu.
.macro ENTRY_ARG_VGA cfunc
cli
cld
PUSHBREGS
movw %ss, %ax // Move %ss to %ds
movw %ax, %ds
movl %esp, %ebx // Backup %esp, then zero high bits
movzwl %sp, %esp
movl %esp, %eax // First arg is pointer to struct bregs
pushw %ax ; callw \cfunc
movl %ebx, %esp // Restore %esp (including high bits)
POPBREGS
.endm
DECLFUNC entry_104f05
entry_104f05:
ENTRY_ARG_VGA vbe_104f05
lretw
DECLFUNC _optionrom_entry
_optionrom_entry:
ENTRY_ARG_VGA vga_post
lretw
DECLFUNC entry_10
entry_10:
ENTRY_ARG_VGA handle_10
iretw
// Entry point using extra stack
DECLFUNC entry_10_extrastack
entry_10_extrastack:
cli
cld
pushw %ds // Set %ds:%eax to space on ExtraStack
pushl %eax
movzwl %cs:ExtraStackSeg, %eax
movl %eax, %ds
movl $(CONFIG_VGA_EXTRA_STACK_SIZE-BREGS_size-8), %eax
popl BREGS_eax(%eax) // Backup registers
popw BREGS_ds(%eax)
movl %edi, BREGS_edi(%eax)
movl %esi, BREGS_esi(%eax)
movl %ebp, BREGS_ebp(%eax)
movl %ebx, BREGS_ebx(%eax)
movl %edx, BREGS_edx(%eax)
movl %ecx, BREGS_ecx(%eax)
movw %es, BREGS_es(%eax)
movl %esp, BREGS_size+0(%eax)
movzwl %sp, %esp
movw %ss, BREGS_size+4(%eax)
movl (%esp), %edx
movl %edx, BREGS_code(%eax)
movw 4(%esp), %dx
movw %dx, BREGS_flags(%eax)
movw %ds, %dx // Setup %ss/%esp and call function
movw %dx, %ss
movl %eax, %esp
pushw %ax ; callw handle_10
movl %esp, %eax // Restore registers and return
movw BREGS_size+4(%eax), %ss
movl BREGS_size+0(%eax), %esp
popl %edx
popw %dx
pushw BREGS_flags(%eax)
pushl BREGS_code(%eax)
movl BREGS_edi(%eax), %edi
movl BREGS_esi(%eax), %esi
movl BREGS_ebp(%eax), %ebp
movl BREGS_ebx(%eax), %ebx
movl BREGS_edx(%eax), %edx
movl BREGS_ecx(%eax), %ecx
movw BREGS_es(%eax), %es
pushw BREGS_ds(%eax)
pushl BREGS_eax(%eax)
popl %eax
popw %ds
iretw