Assembly RSS Assembly RSS

Asm help .Please

Reply

•
•
Join Date: May 2009
Posts: 4
Reputation: LangTuHaoHoa is an unknown quantity at this point 
Solved Threads: 0
LangTuHaoHoa LangTuHaoHoa is offline Offline
Newbie Poster

Asm help .Please

 
0
  #1
May 5th, 2009
For Example .I have a function that code in C++ :
Assembly Syntax (Toggle Plain Text) 
  1. void MyFunc(int s) {
  2. 	struct itemRec {
  3. 		int code;
  4. 		int index;
  5. 	} bItem;
  6. 	bItem.code = 0x0000000B;
  7. 	bItem.index = s;
  8. 	__asm {
  9. 		push	eax
  10.   		push	edx
  11.   		mov	ecx,0x00625388
  12.   		push	00000000h
  13.   		lea	edx,bItem
  14.   		push	edx
  15.   		push	00000016h
  16.   		mov	eax,0x00487273
  17.   		call	eax
  18.   		pop	edx
  19.   		pop	eax
  20. 	}
  21. }

and when I compile that function,so I found in asm that code :

Assembly Syntax (Toggle Plain Text) 
  1.   		push	ebp
  2.   		mov	ebp,esp
  3.   		sub	esp,00000008h
  4.   		mov	eax,[ebp+08h]
  5.   		mov	dword ptr [ebp-08h],0000000Bh
  6.   		mov	[ebp-04h],eax
  7.   		push	eax
  8.   		push	edx
  9.   		mov	ecx,00625388h
  10.   		push	00000000h
  11.   		lea	edx,[ebp-08h]
  12.   		push	edx
  13.   		push	00000016h
  14.   		mov	eax,0x00487273h
  15.   		call	eax
  16.   		pop	edx
  17.   		pop	eax
  18.   		mov	esp,ebp
  19.   		pop	ebp
  20.   		retn

It's my example.So when I search in other asm file,I found that asm code :


Assembly Syntax (Toggle Plain Text) 
  1.   		push	ebp
  2.   		mov	ebp,esp
  3.   		sub	esp,00000008h
  4.   		mov	eax,[ebp+08h]
  5.   		add	eax,eax
  6.   		mov	ecx,[eax+eax+L1000D004]
  7.   		add	eax,eax
  8.   		lea	edx,[ebp+08h]
  9.   		mov	[ebp+08h],ecx
  10.   		mov	[ebp-04h],eax
  11.   		mov	[ebp-08h],edx
  12.   		push	eax
  13.   		push	ecx
  14.   		mov	ecx,ds:[00838344h]
  15.   		add	ecx,0000843Ch
  16.   		add	ecx,00007EBCh
  17.   		push	ecx
  18.   		add	ecx,0000054Ch
  19.   		mov	eax,[ebp-08h]
  20.   		push	eax
  21.   		mov	eax,0051F900h
  22.   		call	eax
  23.   		mov	ecx,[eax+0Ch]
  24.   		cmp	ecx,[ebp+08h]
  25.   		pop	ecx
  26.   		jnz	L100010A8
  27.   		add	eax,00000010h
  28.   		add	ecx,[ebp-04h]
  29.   		mov	[ecx],eax
  30.  L100010A8:
  31.   		pop	ecx
  32.   		pop	eax
  33.   		mov	esp,ebp
  34.   		pop	ebp
  35.   		retn

Please help me and tell me know what the real code in C++ (same my example) .And parameter to function that has address 0051F900h .Please help me
Reply With Quote Quick reply to this message  
•
•
Join Date: Apr 2009
Posts: 39
Reputation: sysop_fb is an unknown quantity at this point 
Solved Threads: 5
sysop_fb sysop_fb is offline Offline
Light Poster

Re: Asm help .Please

 
0
  #2
May 5th, 2009
Either I don't know what you're asking for or this smells like homework.

Anyway the param to the function you were asking about

Assembly Syntax (Toggle Plain Text) 
  1.  
  2. 		mov	eax,[ebp-08h]
  3.   		push	eax
  4.   		mov	eax,0051F900h
  5.   		call	eax

The C calling convention is to push arguments on the stack from right to left. So what do you think the argument passed is?
Reply With Quote Quick reply to this message  
•
•
Join Date: May 2009
Posts: 4
Reputation: LangTuHaoHoa is an unknown quantity at this point 
Solved Threads: 0
LangTuHaoHoa LangTuHaoHoa is offline Offline
Newbie Poster

Re: Asm help .Please

 
0
  #3
May 5th, 2009
SO,I want to know how many arguments in that function,and How to use that function

for example:

void MyFunc(int s) {
struct itemRec {
int code;
int index;
} bItem;
bItem.code = 0x0000000B;
bItem.index = s;
__asm {
push eax
push edx
mov ecx,0x00625388
push 00000000h
lea edx,bItem
push edx
push 00000016h
mov eax,0x00487273
call eax
pop edx
pop eax
}
}


I really want to know how use that function ( 0x0051F900) .So because I don't know how many arguments that push to that function and code for use that function .Please help me.

In your post.You say :

•
•
•
•
mov eax,[ebp-08h]
push eax
mov eax,0051F900h
call eax
So [ebp-08h] is?I don't know type of that argument.
Reply With Quote Quick reply to this message  
•
•
Join Date: May 2009
Posts: 4
Reputation: LangTuHaoHoa is an unknown quantity at this point 
Solved Threads: 0
LangTuHaoHoa LangTuHaoHoa is offline Offline
Newbie Poster

Re: Asm help .Please

 
0
  #4
May 5th, 2009
•
•
•
•
Originally Posted by sysop_fb View Post
Either I don't know what you're asking for or this smells like homework.

Anyway the param to the function you were asking about

Assembly Syntax (Toggle Plain Text) 
  1.  
  2. 		mov	eax,[ebp-08h]
  3.   		push	eax
  4.   		mov	eax,0051F900h
  5.   		call	eax

The C calling convention is to push arguments on the stack from right to left. So what do you think the argument passed is?
If possible,please help me decompile that asm code to real code in C++ .Please see my example to understand what I say .Thanks u
Reply With Quote Quick reply to this message  
•
•
Join Date: May 2009
Posts: 4
Reputation: LangTuHaoHoa is an unknown quantity at this point 
Solved Threads: 0
LangTuHaoHoa LangTuHaoHoa is offline Offline
Newbie Poster

Re: Asm help .Please

 
0
  #5
May 7th, 2009
No one can help me how to use function 0x51F900 and what is arguments pass to that function ? Please help me
Reply With Quote Quick reply to this message  
Reply

Quick Reply to Thread
This thread is more than three months old.
Perhaps start a new thread instead?
•
•
•
•
•
•
•
•
Message:
•
•
•
•



Similar Threads
Other Threads in the Assembly Forum
Thread Tools Search this Thread



3d 68hc11 6811 adress array asm assembler assembly boot bootloader buffer compression cursor debug directory division dos draw emulator endtask file int10h integer interrupt language loop nohau osdevelopment print program range read remainder shape string text tsr x86
About Us | Contact Us | Advertise | DaniWeb | Acceptable Use Policy | RSS Feed

©2003 - 2009 DaniWeb® LLC