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derPENGUIN



Joined: 09 Jul 2006
Posts: 5
derPENGUIN
sry, newbie-question...

Good morning.
I want to store some adresses in an array. That is my code:
Code:
DATA
index dd 0x0
offset dd 0x0
count dd 0x0
wp: times 255 dd 0x0

CODE
build_array:
    cmp [index],0
    jnz no_main
    mov [offset],edi
  no_main:
    mov eax,[index]
    inc eax
    mov [wp+eax],edi                ; in edi we got the structure offset
    mov [index],eax
    mov [count],eax
ret

PSEUDO
printf("count:%d\n",[count]); //corrrect
printf("point:%d\n",[wp+someIndex]); //incorrrect
    


I cannot figure out, where it stores the data, but eax counts fine. What is wrong?
The second question will be: how can I access the content of address, which is written to wp+ìndex?

Thanks

PS.: Using FASM 1.66 on MenuetOS
Post 16 Jul 2006, 06:13
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viki



Joined: 03 Jan 2006
Posts: 40
Location: Czestochowa, Poland
viki
there is no loop for filling array
Code:

  xor bx,bx
loop:
  mov [array+bx],bx
  inc bx
  cmp bx,5
  jne loop
    
Post 16 Jul 2006, 08:04
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JohnnyReb



Joined: 25 Jun 2006
Posts: 8
JohnnyReb
I'm kinda new myself, but try:

mov [wp+eax*4],edi

to index into a DWORD array.

_________________
JohnnyReb
Win if you can, Lose if you must, but always cheat!
Post 16 Jul 2006, 10:43
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viki



Joined: 03 Jan 2006
Posts: 40
Location: Czestochowa, Poland
viki
and what about this
Code:
mov esi,src
mov edi,dst
mov cx,len
rep stosd
    
Post 16 Jul 2006, 17:05
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derPENGUIN



Joined: 09 Jul 2006
Posts: 5
derPENGUIN
Thank you for reply.
viki:
A loop is not needed, because I use it as a function. Its for a library and I dont know the count of calls. And yuor second example, the same, I dont have len.
Johnny:
yes, tha was it. eax*4 works. Now I will try to access the content of this saved addresses. If you have any idea, please tell me.

Much thanks,
Frank
Post 17 Jul 2006, 08:13
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JohnnyReb



Joined: 25 Jun 2006
Posts: 8
JohnnyReb
Access a DWORD array the same way:

printf("point:%d\n",[wp+eax*4]);

or (if it requires pushing on the stack)

mov esi,[wp+eax*4)
printf("point:%d\n",esi);

_________________
JohnnyReb
Win if you can, Lose if you must, but always cheat!
Post 17 Jul 2006, 10:46
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derPENGUIN



Joined: 09 Jul 2006
Posts: 5
derPENGUIN
thx, I solved it in this way:
mov edi,[wp+eax*4]
printf("point:%d\n",[edi])

BTW, printf is not an asm keyword, is it? I am really better in C as in asm, but actually I´m coding for Menuet, the output there is with int 40, but I think, that is not related to my problem, therefor I used the C syntax.

Much thanks again and cu with further problems, I´m sure Wink
Post 17 Jul 2006, 21:10
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