38 lines
885 B
NASM
38 lines
885 B
NASM
[SECTION .user]
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global user_test
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user_test:
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mov dword [0xb8000], 0x0f000f00 | 'U' | 's' << 16
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mov dword [0xb8004], 0x0f000f00 | 'e' | 'r' << 16
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mov dword [0xb8008], 0x0f000f00 | 'm' | 'o' << 16
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mov dword [0xb800C], 0x0f000f00 | 'd' | 'e' << 16
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mov word [0xb8010], 0x0f00 | '!'
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mov eax, 0 ; command = 00h, get key
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int 0x21 ; OS call
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push 0x00000013 ; eax AH=0,AL=3 set video mode 3
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push 0x00000000 ; ecx
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push 0x00000000 ; edx
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push 0x00000000 ; ebx
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push 0x00000000 ; esi
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push 0x00000000 ; edi
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push esp ; regs
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push 0x10 ; interrupt
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mov eax, 0x86 ; command = 86h, virtual 8086 call
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int 0x21 ; OS call
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mov edi, 0xA0000
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xor eax, eax
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.loop:
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mov ecx, 320
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rep stosb
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inc al
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cmp eax, 200
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jl .loop
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mov eax, 0xA0000
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;mov ecx, 1000000000
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;.dbg:
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;loop .dbg
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int 0x30 ; Exit
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mov edx, 0x105000 ; somewhere in kernel mem
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mov edx, [edx] ; should page fault
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xor ebx, ebx
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div bl ; Unhandled DIV0 exception
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