21 lines
766 B
NASM
21 lines
766 B
NASM
bits 32
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; !!! GDT !!!
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; This will set up our new segment registers. We need to do
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; something special in order to set CS. We do what is called a
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; far jump. A jump that includes a segment as well as an offset.
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; This is declared in C as 'extern void gdt_flush();'
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global _i86_gdt_flush ; Allows the C code to link to this
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extern _gp ; Says that '_gp' is in another file
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_i86_gdt_flush:
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lgdt [_gp] ; Load the GDT with our '_gp' which is a special pointer
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mov ax, 0x10 ; 0x10 is the offset in the GDT to our data segment
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mov ds, 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 ss, ax
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jmp 0x08:flush2 ; 0x08 is the offset to our code segment: Far jump!
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flush2:
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ret ; Returns back to the C code!
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