Boch Debugging

[Annie]

Hi Mike,

I like the series very much, and trying to follow it.

However, I have a request. Maybe when you got time you can add to the series. It is a chapter to teach how to debug in boch. Sometimes when I ran into problems it is such a pain to find out what is wrong. I guess some knowledge of debugging would help very much.

And very nice chapter on "Graphic" part.

Thank

[Andyhhp]

If you need a quick intro to debugging, read this link

http://bochs.sourceforge.net/cgi-bin/to ... oc/docbook

The 3 sections you need for basic debugging is Execution Control (c s q), Breakpoints (b) and Info sections.

[Annie]

hi, thank a lot for the link. I have another question regarding Bochs Debug. Suppose that inside your code you have a function, say Print and its called in the main program. Now if you are stepping the code with Bochs debug, when get to the function call, it will step into the function. Is there away we can step over that, without getting inside?

thanks in advance

[Mike]

Hello,

You can set a breakpoint after the function call instruction and continue execution. When the breakpoint is hit, you will be back into the debugger.

The continue command is "c". There is two ways to make a breakpoint, either using the "b" command in the debugger (for example, b 0x7c00 sets a breakpoint to 0x7c00) or a "magic breakpoint". To enable this, add magic_break: enabled=1 in your configuration file. Now, place a xchg bx, bx instruction at the location you want to set a breakpoint at and it will break into the bochs debugger.