StupidOS/kernel/boot/idt.s

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;; File: idt.s
;;
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[BITS 32]
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%include "sys/i386/cpu.inc"
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section .text
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idt_set_table:
push ebp
mov ebp, esp
mov ecx, [ebp + 8]
extern isr_list
mov eax, [isr_list + (ecx * 4)]
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; offset (low)
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mov word [idt_entries + (ecx * 8)], ax
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; segment selector (kernel code)
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mov word [idt_entries + (ecx * 8) + idt_gate.selector], 0x08
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; zero (skip)
; attr: 1 (Present) 00 (DPL) 0 1 (D: 32bits) 110
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mov byte [idt_entries + (ecx * 8) + idt_gate.attributes], 0x8E
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; offset (high)
shr eax, 16
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mov word [idt_entries + (ecx * 8) + idt_gate.offset_high], ax
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leave
ret
global idt_setup
idt_setup:
%assign i 0
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%rep 32
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push dword i
call idt_set_table
add esp, 4
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%assign i i+1
%endrep
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lidt [idt_ptr]
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sti
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ret
section .data
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align 8
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idt_ptr:
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dw idt_entries.end-idt_entries-1
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dd idt_entries
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; variable: idt_entries
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align 8
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idt_entries:
times 256 dd 0x00000000, 0x00000000
.end: