36 lines
1.5 KiB
NASM
36 lines
1.5 KiB
NASM
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global ivt
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ivt: dd 0x00000000
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global gdt_desc
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gdt_desc:
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dw gdt_end - gdt
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dd gdt
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gdt:
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gdt_null: dq 0
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gdt_code: dw 0xFFFF, 0 ; bits 0-15 limit (4GB), bits 0-15 base address
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db 0 ; bits 16-23 base address
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db 10011010b ; access byte
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db 11001111b ; bits 16-19 limit (4GB), 4 bits flags
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db 0 ; bits 24-31 base address
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gdt_data: dw 0xFFFF, 0 ; bits 0-15 limit (4GB), bits 0-15 base address
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db 0 ; bits 16-23 base address
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db 10010010b ; access byte
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db 11001111b ; bits 16-19 limit (4GB), 4 bits flags
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db 0 ; bits 24-31 base address
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gdt_r3code: dw 0xFFFF, 0 ; bits 0-15 limit (4GB), bits 0-15 base address
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db 0 ; bits 16-23 base address
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db 0xFA ; access byte
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db 11001111b ; bits 16-19 limit (4GB), 4 bits flags
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db 0 ; bits 24-31 base address
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gdt_r3data: dw 0xFFFF, 0 ; bits 0-15 limit (4GB), bits 0-15 base address
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db 0 ; bits 16-23 base address
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db 0xF2 ; access byte
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db 11001111b ; bits 16-19 limit (4GB), 4 bits flags
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db 0 ; bits 24-31 base address
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gdt_tss: dw 0x2080, 0x0000;26*4, tss_data ; bits 0-15 limit (4GB), bits 0-15 base address
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db 0x20 ; bits 16-23 base address
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db 0x89 ; access byte
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db 00000000b ; bits 16-19 limit (4GB), 4 bits flags
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db 0 ; bits 24-31 base address
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gdt_end:
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