Re: howto disassemble without debug information

[Keith Seitz <keiths at redhat dot com>]

Marco Cavallini wrote:
> > > Sorry for the misunderstanding.
> > > Seems hard to explain what I want to do, but every commercial 
> > > debugging software I tested has this feature and I'm wondering if 
> > > insight/gdb can do the same.
> > > I actually need trace the execution step-by-stp of assembler code 
> > > without debug info, is it possible and how ?
> > > I don't care about breakpoints at the moment it was only an example.
> > > The best I've done until now is to show the disassembled of binary 
> > > code with : (gdb) x/10i 0x0
> >
> > Read the GDB documentation or do "help stepi".
>
> This seems what I was looking for, thank you.
>
> Last question: is it possible to see the ASM code and execute a step 
> from inside INSIGHT using a mouse click (always without debug info) ?
> I haven't found this feature.
>
> Does exist a manual for INSIGHT

Actually, you're going to run into a lot of trouble using an 
assembler-only approach to debugging. GDB was simply never written to 
deal properly with this situation. As a result, Insight won't be of much 
help in this regard, either.

Source code display for assembler really does require some minimal debug 
info (even just minimal symbols from the compiler would do). As you've 
already discovered, Insight will only display assembler within the 
bounds of a function. It acts the same way gdb's "disassemble" command 
does. There is no insight equivalent of gdb's "x/i" command.

But there could be a way to improve this situation for yourself. You 
could, for example, build the target's executable with full debugging 
info and then process (eg, strip the debug info) this to generate 
something to download to the board. That way at least, gdb would have 
full access to symbols. (That's where "exec-file" and "symbol-file" 
commands come in handy.)

If the source code is all assembler (no C/C++/etc), it could still work. 
GAS does (or used to?) put some debugging information into the object 
files, but it requires much more programmer diligence to use.

Sorry, but Insight this was never really a requirement for Insight, and 
no one has gone back and implemented something a little more robust yet.

Keith