哪位高手能解释这段386为何出错吗？马上给分！
org 0100h
jmp start8086
;-----------------------------------------------------
[SECTION .gdt]
%macro Descriptor 3
dw%2 & 0FFFFh
dw%1 & 0FFFFh
db(%1 >> 16) & 0FFh
dw((%2 >> 8) & 0F00h) | (%3 & 0F0FFh)
db(%1 >> 24) & 0FFh
%endmacro
gdt_desc:Descriptor 0,0,0
code_desc:Descriptor 0,0,98h+4000h
data_desc:Descriptor 0b800h,0ffffh,92h
gdt_lenequ $-gdt_desc
gdt_ptrdw gdt_len - 1
dd 0
sel_codeequ code_desc - gdt_desc
sel_dataequ data_desc - gdt_desc
;-----------------------------------------------------
[SECTION .s16]
[BITS16]
start8086:
mov ax,cs
mov ds,ax
mov es,ax
mov ss,ax
mov sp,100h
;*** initialize code descriptor ****
xoreax, eax
movax, cs
shleax, 4
addeax, start386
movword [code_desc + 2], ax
shreax, 16
movbyte [code_desc + 4], al
movbyte [code_desc + 7], ah
;*** load GDTR register ****
xoreax, eax
movax, ds
shleax, 4
addeax, gdt_desc
movdword [gdt_ptr + 2], eax
lgdt [ gdt_ptr ]
lgdt[gdt_ptr]
cli
inal, 92h
oral, 00000010b
out92h, al
moveax, cr0
oreax, 1
movcr0, eax
jmpdword sel_code:0
[SECTION .s32]
[BITS32]
start386:
mov ax,sel_data
mov es,ax
mov al,'X'
mov [es:180*10+20],al
jmp $
[解决办法]
给你改了一下，应该没有什么问题啦：
%macro Descriptor 3 dw %2 & 0FFFFh dw %1 & 0FFFFh db (%1 >> 16) & 0FFh dw ((%2 >> 8) & 0F00h) | (%3 & 0F0FFh) db (%1 >> 24) & 0FFh %endmacro org 07C00h jmp start8086gdt_desc: Descriptor 0, 0, 0code_desc: Descriptor 0, SegLen -1 , 98h+4000h ; 修改段界限data_desc: Descriptor 0B8000h, 0FFFFh, 92h gdt_len equ $ - gdt_descgdt_ptr dw gdt_len - 1 dd 0 sel_code equ code_desc - gdt_descsel_data equ data_desc - gdt_desc;[SECTION .s16][BITS 16] start8086: mov ax,cs mov ds,ax mov es,ax mov ss,ax mov sp,100h ;*** initialize code descriptor **** xor eax, eax mov ax, cs shl eax, 4 add eax, start386 mov word [code_desc + 2], ax shr eax, 16 mov byte [code_desc + 4], al mov byte [code_desc + 7], ah ;*** load GDTR register **** xor eax, eax mov ax, ds shl eax, 4 add eax, gdt_desc mov dword [gdt_ptr + 2 ], eax lgdt [gdt_ptr] cli in al, 92h or al, 00000010b out 92h, al mov eax, cr0 or eax, 1 mov cr0, eax jmp dword sel_code:0 ;[SECTION .s32][BITS 32] start386: mov ax, sel_data mov es,ax ; 设置显示的属性 mov ah, 0Ch mov al,'X' mov [es:((80*0+0)*2)],ax ;个人感觉这样写行列容易看出 jmp $SegLen equ $ - start386 ; 添加这一句; 补齐剩余的字节和扇区结束标识times 510 - ($ - $$) db 0 dw 0xaa55
