blob: dbb40527afb3068e33b662a568ca881f2b6041b7 (
plain)
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
|
MBALIGN equ 1<<0 ; Align loaded modules on page boundries */
MBMEMINFO equ 1<<1 ; Provide memory map*/
MBFLAGS equ MBALIGN | MBMEMINFO ; Multiboot flag field*/
MAGIC equ 0x1BADB002 ;Lets bootloader find header*/
CHECKSUM equ -(MAGIC + MBFLAGS) ; Proves we are multiboot via checksum*/
CODESEG equ 0x08
DATASEG equ 0x10
section .multiboot
align 4
dd MAGIC
dd MBFLAGS
dd CHECKSUM
section .bss
align 16
stack_bottom:
resb 16384
stack_top:
section .text
global gdtr
gdtr:
dw 0
dd 0
global idtr
idtr:
dw 0
dd 0
global _start:function (_start.end - _start)
_start:
mov esp, stack_top
extern get_gdtr
call get_gdtr
cli
lgdt [gdtr]
mov eax, cr0
or al, 1
mov cr0, eax
call reloadSegments
extern get_idtr
call get_idtr
lidt [idtr]
sti
xchg bx, bx
[bits 32]
extern kernel_main
call kernel_main
; BOCHS
cli
.hang: hlt
jmp .hang
.end:
reloadSegments:
JMP CODESEG:.reload_CS ; should def define a CODESEG
.reload_CS:
MOV AX, DATASEG
MOV DS, AX
MOV ES, AX ; TODO: Setup proper extra segment
MOV FS, AX ; TODO: Setup proper General purpose segments
MOV GS, AX ; ...
MOV SS, AX ; TODO: Setup proper stack segment
RET
|
