1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
// 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
.code16
.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 implements a call while avoiding instructions
// that old versions of x86emu have problems with.
.macro VGA_CALLL cfunc
#if CONFIG_VGA_FIXUP_ASM
pushw %ax
callw \cfunc
#else
calll \cfunc
#endif
.endm
// This macro is the same as ENTRY_ARG except VGA_CALLL is used.
.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
VGA_CALLL \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
movw %cs:ExtraStackSeg, %ds
movl $(CONFIG_VGA_EXTRA_STACK_SIZE-PUSHBREGS_size-16), %eax
SAVEBREGS_POP_DSEAX // Save registers on extra stack
movl %esp, PUSHBREGS_size+8(%eax)
movw %ss, PUSHBREGS_size+12(%eax)
popl BREGS_code(%eax)
popw BREGS_flags(%eax)
movw %ds, %dx // Setup %ss/%esp and call function
movw %dx, %ss
movl %eax, %esp
VGA_CALLL handle_10
movl %esp, %eax // Restore registers and return
movw PUSHBREGS_size+12(%eax), %ss
movl PUSHBREGS_size+8(%eax), %esp
popl %edx
popw %dx
pushw BREGS_flags(%eax)
pushl BREGS_code(%eax)
RESTOREBREGS_DSEAX
iretw
// Timer irq handling
DECLFUNC entry_timer_hook
entry_timer_hook:
ENTRY handle_timer_hook
ljmpw *%cs:Timer_Hook_Resume
// Timer irq handling on extra stack
DECLFUNC entry_timer_hook_extrastack
entry_timer_hook_extrastack:
cli
cld
pushw %ds // Set %ds:%eax to space on ExtraStack
pushl %eax
movw %cs:ExtraStackSeg, %ds
movl $(CONFIG_VGA_EXTRA_STACK_SIZE-PUSHBREGS_size-8), %eax
SAVEBREGS_POP_DSEAX
movl %esp, PUSHBREGS_size(%eax)
movw %ss, PUSHBREGS_size+4(%eax)
movw %ds, %dx // Setup %ss/%esp and call function
movw %dx, %ss
movl %eax, %esp
calll handle_timer_hook
movl %esp, %eax // Restore registers and return
movw PUSHBREGS_size+4(%eax), %ss
movl PUSHBREGS_size(%eax), %esp
RESTOREBREGS_DSEAX
ljmpw *%cs:Timer_Hook_Resume
|
