; Initial GDT for kernel, which wants a flat code and data descriptor gdt: dw .end-.start-1 dd .start .start: dq 0 ; null descriptor .code: dw 0xffff dw 0 db 0 db 10011010b db 11001111b db 0 .data: dw 0xffff dw 0 db 0 db 10010010b db 11001111b db 0 .end: