Exetools

Exetools (https://forum.exetools.com/index.php)
-   General Discussion (https://forum.exetools.com/forumdisplay.php?f=2)
-   -   Hex values for jumps and thier functions please? VB? (https://forum.exetools.com/showthread.php?t=3180)

CrAcKaHoLic 01-09-2004 09:31

Hex values for jumps and thier functions please? VB?
 
Yes, I am a newbie and I am unsure of the exact terminology but the values 90, E9 and others are what I am asking about. I would like to get a table of all useable values and thier functions or explanation of proper usage guidelines. Does anyone have a link to such information or could you share your knowlege?

I am using W32dasm and a hex editor to get past registration and nag screens. I find the proper MOVs, CMPs and Jumps but I am unsure of the values to use in the offset to force the jump always. Thanks

Satyric0n 01-09-2004 16:36

The Intel Instruction Set Reference (hxxp://www.intel.com/design/pentium4/manuals/245471.htm) has a verbose list of all instructions and their hex values. For jumps, look at the Jcc instructions.

Also, Squidge's excellent tool RTA (hxxp://www.ibiblio.org/paulc/rta/) is helpful in this area.

Nilrem 01-09-2004 19:02

Just a couple for a quick reference:
90 - NOP
74 - Jump if Equal
75 - Jump if Not Equal
84/85 same as the above
EB - Straight Jump

These should get you by for now if you're getting rid of nags etc
(Information may be incorrect, just off the top of my head).

Jay 01-09-2004 19:58

its all relative
 
Hi,
google for "Calculating Offsets. by Lord Rhesus" or if you don't want to calculate it on your fingers :) there are tools available,"Muad'Dib jump generator" for one.
regards

CrAcKaHoLic 01-10-2004 02:54

Hi, and thanks for all the help. I have managed to crack this program with help from these boards and continue to learn new things. Take care.


All times are GMT +8. The time now is 16:37.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2026, vBulletin Solutions, Inc.
Always Your Best Friend: Aaron, JMI, ahmadmansoor, ZeNiX