]> Joshua Wise's Git repositories - netwatch.git/blame - aseg/aseg.asm
Fix 'i r retard' bug in timer
[netwatch.git] / aseg / aseg.asm
CommitLineData
eee8da2e 1 org 0xA8000
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2[bits 16]
3entry:
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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
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7 mov fs, ax
8 mov gs, ax
9 mov ss, ax
eee8da2e 10 jmp 0xA800:(entry2-0xA8000) ; Long jump to a correct cs.
f23390bf 11entry2:
eee8da2e 12 lgdt [(gdtr-0xA8000)] ; Set up a new GDT.
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13 mov eax, 0x1
14 mov cr0, eax ; ... and enter pmode!
eee8da2e 15 jmp long 0x10:continue ; Now longjmp into the new code.
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16[bits 32]
17continue:
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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
1458b275 24 mov esp, [dataptr] ; Load stack pointer.
015cd976 25
f2b87dd6 26 mov eax, [dataptr+4] ; Load target jump address
1458b275 27 call eax ; then jump into C.
015cd976 28
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29 rsm ; and leave SMM
30
31 align 0x4
32gdtr:
9b8c947b 33 db 0x17, 0x00
eee8da2e 34 dd gdt
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35 align 0x4
36gdt:
1458b275 37 db 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ; initial null entry
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38 db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x93, 0xCF, 0x00 ; data segment
39 db 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x9B, 0xCF, 0x00 ; code segment
f23390bf 40
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41dataptr:
42 ; 4 bytes of stack top
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43 ; 4 bytes of C entry point
44 ; These show up
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