63 lines
1.1 KiB
NASM
63 lines
1.1 KiB
NASM
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%include "bootdef.inc"
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%define GDT 0x140000
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%define IDT 0x150000
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[global start]
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[extern _isr]
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[extern _k_init]
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bits 32
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start:
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cli ;if they weren't already off
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mov edi, GDT
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mov esi, gdt
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mov ecx, gdt_end-gdt
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copy_gdt:
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lodsb
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stosb
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loop copy_gdt
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mov edi, IDT ;destination
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mov esi, isr_0 ;address of isr0
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mov edx, isr_1-isr_0 ;distance between isr labels
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mov ecx, 50 ;number of isrlabels
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fill_idt:
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mov ebx, esi
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mov ax, si
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stosw ;0 offset 15:0
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mov ax, KERNEL_CODE
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stosw ;2 selector 15:0
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mov ax, 0x8E00
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stosw ;4 [P][DPL][0][TYPE][0][0][0][0][0][0][0][0]
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shr esi, 16
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mov ax, si
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stosw ;6 offset 31:16
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mov esi, ebx
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add esi, edx
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loop fill_idt
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lgdt [gdtr] ;load gdt
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jmp KERNEL_CODE:newgdtcontinue
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newgdtcontinue:
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mov ax, KERNEL_DATA
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mov es, ax
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mov ds, ax
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mov gs, ax
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mov fs, ax
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mov ss, ax
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mov esp, 0x1ffffc ;stack just under 2mb, moves downward
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lidt [idtr] ;load idt
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call _k_init
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hlt ;halt processor when k_init is done
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jmp $ ;shouldn't get here...
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%include "gdt.inc"
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%include "idt.inc"
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