可以GET到PCIE值了，但是還有一個顯示的問題，請多多指教

[qoocc1]

請問 mov esi, 0E0000040h
mov dword ptr eax,fs:[esi]
這個指令不是可以get 4BYTE的值嗎?可是我螢幕只有顯示一個值，請多多指教。


CODE如下:

.model small
.586p

DSEG SEGMENT USE16

DESC STRUC
LimitL DW 0 ;段界限(BIT0-15)
BaseL DW 0 ;段基地址(BIT0-15)
BaseM DB 0 ;段基地址(BIT16-23)
Attributes DB 0 ;段屬性
LimitH DB 0 ;段界限(BIT16-19)
BaseH DB 0 ;段基地址(BIT24-31)
DESC ENDS

PDesc STRUC
Limit DW 0 ;16位界限
Base DD 0 ;32位基地址
PDesc ENDS

GDT_def Label Fword
Null_Desc DESC < 0h, 0h, 00h, 00h, 000h, 0>
Data_Desc DESC < 0FFFFh, 0h, 00h, 92h, 08Fh, 0>

GDT_Addr PDesc <$-GDT_def-1>;
DSEG ENDS

CSEG SEGMENT USE16
ASSUME CS:CSEG,DS:DSEG


.Startup
call Set4gb
;
;

mov esi, 0E0000040h
mov dword ptr eax,fs:[esi];問題處
mov ah,al
mov cl,4
shr ah,cl
mov cl,al
.if ah >= 10
add ah,'A'-10
.else
add ah,'0'
.endif
mov dl,ah
mov ah,2
int 21h

and cl,00001111b
.if cl >= 10
add cl,'A'-10
.else
add cl,'0'
.endif
mov dl,cl
mov ah,2
int 21h





; write your code in here.
;
.exit

Set4gb PROC NEAR
mov eax, ds
shl eax, 4
xor ebx, ebx
mov bx, offset GDT_def
add eax, ebx
mov dword ptr GDT_Addr+2, eax
lgdt fword ptr GDT_Addr


cli

; mov word ptr GDT_Addr, (2*8-1);



in al, 92h
or al, 002
out 092h, al
out 0edh, al

mov bx, 8
mov eax, cr0
or al, 1
mov cr0, eax

jmp pMod
pMod:

mov fs, bx
mov gs, bx
and al, 0FEh
mov cr0, eax

jmp rMod
rMod:

mov ax, 0
mov fs, ax
mov gs, ax


sti
ret
Set4gb ENDP

CSEG ENDS
end

[xtdumpling]

.model small 
.586p 

DSEG  SEGMENT  USE16                

DESC            STRUC 
        LimitL          DW      0 ;段界限(BIT0-15) 
        BaseL          DW      0 ;段基地址(BIT0-15) 
        BaseM          DB      0 ;段基地址(BIT16-23) 
        Attributes      DB      0 ;段屬性 
        LimitH          DB      0 ;段界限(BIT16-19) 
        BaseH          DB      0 ;段基地址(BIT24-31) 
DESC            ENDS 

PDesc          STRUC 
        Limit          DW      0 ;16位界限 
        Base            DD      0 ;32位基地址 
PDesc          ENDS 

GDT_def        Label  Fword 
Null_Desc      DESC    <    0h,  0h, 00h, 00h, 000h, 0> 
Data_Desc      DESC    < 0FFFFh,  0h, 00h, 92h, 08Fh, 0> 

GDT_Addr        PDesc  <$-GDT_def-1>; 
DSEG            ENDS                          

CSEG            SEGMENT USE16                
                ASSUME  CS:CSEG,DS:DSEG 
            
                
.Startup 
        call      Set4gb 
; 
;      

        mov      esi, 0E0000040h 
        mov      dword ptr eax,fs:[esi];問題處 

        bswap eax
        mov cx,4
@@:
        push cx
        push eax
        mov ah,al 
        mov cl,4 
        shr ah,cl 
        mov cl,al 
        .if ah >= 10 
        add ah,'A'-10 
        .else 
        add ah,'0' 
        .endif 
        mov dl,ah 
        mov ah,2 
        int 21h 
    
        and cl,00001111b 
        .if cl >= 10 
        add cl,'A'-10 
        .else 
        add cl,'0' 
        .endif 
        mov dl,cl 
        mov ah,2 
        int 21h
        
        pop eax
        mov cl,8
        ror eax,cl
        pop cx
        loop @b

;      write your code in here. 
; 
        .exit 
        
Set4gb          PROC      NEAR 
        mov      eax, ds 
        shl      eax, 4 
        xor      ebx, ebx 
        mov      bx, offset GDT_def 
        add      eax, ebx 
        mov      dword ptr GDT_Addr+2, eax 
        lgdt      fword ptr GDT_Addr 


        cli 

      ; mov      word ptr GDT_Addr, (2*8-1); 

      
        
        in        al, 92h 
        or        al, 002 
        out      092h, al 
        out      0edh, al 
        
        mov      bx, 8 
        mov      eax, cr0 
        or        al, 1 
        mov      cr0, eax 

        jmp      pMod 
    pMod: 

        mov      fs, bx 
        mov      gs, bx 
        and      al, 0FEh 
        mov      cr0, eax 
        
        jmp      rMod 
    rMod: 

        mov      ax, 0 
        mov      fs, ax 
        mov      gs, ax 
        

        sti 
        ret 
Set4gb  ENDP 
      
CSEG          ENDS
        end

[qoocc1]

謝謝xtdumpling大大，還有幾個問題請各位請教各位，謝謝。

(1) GDT_def Label Fword
定義成6個byte，但是如何裝入8個byte呢?

(2) mov dword ptr GDT_Addr+2, eax
lgdt fword ptr GDT_Addr

為什麼GDT_Addr+2要加2呢?加2的意義為何?
lgdt fword ptr GDT_Addr
lgdt fword為什麼只LOAD 6個BYTE不用QWORD全部lOAD進去呢?

(3) 有哪個指令可以跳過CR0這一行呢?用T都會REBOOT

[wap21]

友情up

[qqlpp]

不懂，up