Cheat Engine

iPromise · Posted: Fri May 25, 2012 9:33 pm Post subject: Hardware Breakpoints

I understand that the DR0 - DR3 registers are the registers where you set the address for your breakpoint. I can't seem to understand how the Dr7 register works though. I do know that they are the conditions set for the breakpoint but what i'm doing doesn't work.

Innovation · Posted: Fri May 25, 2012 10:08 pm Post subject:

You need to set the debug registers in every thread in the process (excluding the one in which you're doing this). Also, you should use SuspendThread and ResumeThread respectively before and after messing with the registers to ensure you don't accidentally screw up the context as the thread is still running. See this for an example.

To correctly use DR0 in your case, you should set the 0th, 16th, and 17th bits and unset the 1st, 18th, and 19th bits of DR7 (assuming you only want a breakpoint for one byte).