pm.incbash
%macro Descriptor 3 dw %2 & 0FFFFh dw %1 & 0FFFFh db (%1 >> 16) & 0FFh dw ((%2 >> 8) & 0F00h) | (%3 0F0FFh) db (%1 >> 24) & 0FFh %endmacro
pmtest1.asmide
%include "pm.inc" org 07c00h jmp LABEL_BEGIN [SECTION .gdt] ; 段基址，段界限，屬性（段界限 2bytes, 段基址 4bytes） LABEL_GDT: Descriptor 0, 0, 0 LABEL_DESC_CODE32: Descriptor 0, SegCode32Len - 1, DA_C + DA_32 LABEL_DESC_VIDEO: Descriptor 0B8000h, 0ffffh, DA_DRW GdtLen equ $ - LABEL_GDT GdtPtr dw GdtLen - 1 dd 0 SelectorCode32 equ LABEL_DESC_CODE32 - LABEL_GDT SelectorVideo equ LABEL_DESC_VIDEO - LABEL_GDT [SECTION .s16] [BITS 16] LABEL_BEGIN: mov ax, cs mov ds, ax mov es, ax mov ss, ax mov sp, 0100h xor eax, eax mov ax, cs shl eax, 4 add eax, LABEL_SEG_CODE32 mov word [LABEL_DESC_CODE32 + 2], ax shr eax, 16 mov byte [LABEL_DESC_CODE32 + 4], al mov byte [LABEL_DESC_CODE32 + 7], ah xor eax, eax mov ax, ds shl eax, 4 add eax, LABEL_GDT mov dword [GdtPtr + 2], eax lgdt [GdtPtr] cli in al, 92h or al, 00000010b out 92h, al mov eax, cr0 or eax, 1 mov cr0, eax jmp dword SelectorCode32:0 [SECTION .s32] [BITS 32] LABEL_DESC_CODE32: mov ax, SelectorVideo mov gs, ax mov edi, (80 * 11 + 79) * 2 mov ah, 0ch mov al, 'p' jmp $ SegCode32Len equ $ - LABEL_SEG_CODE32