]> Joshua Wise's Git repositories - netwatch.git/blame - aseg-paging/entry.asm
Wait for completion before we pull the trigger on the pbuf
[netwatch.git] / aseg-paging / entry.asm
CommitLineData
9e2a82e4
JP
1 org 0xA8000
2[bits 16]
3entry:
4 mov ax, 0xA800 ; Take us out of flat unreal mode,
5 mov ds, ax ; and put us in true real mode.
6 mov es, ax
7 mov fs, ax
8 mov gs, ax
9 mov ss, ax
10 jmp 0xA800:(entry2-0xA8000) ; Long jump to a correct cs.
11entry2:
12 lgdt [(gdtr-0xA8000)] ; Set up a new GDT.
13 mov eax, 0x1
14 mov cr0, eax ; ... and enter pmode!
15 jmp long 0x10:continue ; Now longjmp into the new code.
16[bits 32]
17continue:
18 mov ax, 0x08 ; Set up segment selectors.
19 mov ds, ax
20 mov es, ax
21 mov fs, ax
22 mov gs, ax
23 mov ss, ax
24 mov esp, [dataptr] ; Load stack pointer.
25
26 mov eax, [dataptr+4] ; Load target jump address
27 call eax ; then jump into C.
28
29 rsm ; and leave SMM
30
31 align 0x4
32gdtr:
33 db 0x17, 0x00
34 dd gdt
35 align 0x4
36gdt:
37 db 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ; initial null entry
38 db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x93, 0xCF, 0x00 ; data segment
39 db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x9B, 0xCF, 0x00 ; code segment
40
41
42dataptr:
43 ; 4 bytes of stack top
44 ; 4 bytes of C entry point
45 ; These show up
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