22 lines
538 B
NASM
22 lines
538 B
NASM
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[bits 16]
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enter_protected:
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cli ; Disable interrupts
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lgdt [gdt_descriptor] ; load the GDT
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mov eax, cr0
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or eax, 0x1 ; set 32-bit mode bit
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mov cr0, eax
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jmp CODE_SEG:init_protected ; far jump into a different segment
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[bits 32]
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init_protected: ; now in 32bit
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mov ax, DATA_SEG ; update segment registers
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mov ds, ax
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mov ss, ax
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mov es, ax
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mov fs, ax
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mov gs, ax
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mov ebp, 0x90000 ; update stack to top of free space
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mov esp, ebp
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call BEGIN_PROTECTED ; call known label with useful code
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