I am trying to set a breakpoint that works by applying a condition. More precisely, I am trying to change the count increment in the AL register by placing a breakpoint condition saying AL = Al - 1 but it doesn't seem to apply ?!

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How it Looked when done correctly enter image description here

  • but , i have seen videos with people doing that ?
    – user4748
    May 31, 2014 at 8:23
  • Yea but i am looking at a tut and the guy does it fine will post pic in question
    – user4748
    May 31, 2014 at 8:27
  • The Tutorial showed a method of having a breakpoints that would change the line at a certain address without having to break at it , even though I am not sure how he did this my best solution was to allow the program to break at the point and then run my cursor out of the loop. It did the exact same thing but just differently.
    – user4748
    May 31, 2014 at 8:39

1 Answer 1


Whatever you enter in the "Condition" field is executed as an IDC script. According to the IDA debugger documentation, the action is supposed to be a test. It's unclear if it explicitly allows assignments or if it's just a side effect that sometimes works.

Try something like this instead: SetRegValue(al-1, "al")

I don't have IDA on hand to test this out, but the function returns true so it might avoid the problem you're seeing.

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