How to resolve a register

[DABhand]

Well obviously some games or application may use a single op code


Like


Move [eax+5],ecx

EAX register changes accordingly, and somewhere else in the program it jumps to this op code.


Now that in mind, and you know initially what address the game is using to store say bullets and you come across an op code like this with multiple uses.

You set a breakpoint to read on the address you found for the bullets, and look for alternatives to that op code.

If you can trace back you will find where the EAX register had a value placed into it before going to this op code. And its a good chance there you can code cave to force a value into that address.