Question about disassembly

Question about disassembly

[Mahmood Naderan]

Hi
How can I debug disassembly instructions with "step" or "next"?
Right now, then I use 'n' it seems that gdb executes multiple assembly
instructions and then stops. Sound like it uses the source level debugging.

Any idea about that?

Regards,
Mahmood

Re: Question about disassembly

[Christian Biesinger]

On Thu, Mar 11, 2021, 13:07 Mahmood Naderan via Gdb <gdb@sourceware.org>
wrote:

> Hi
> How can I debug disassembly instructions with "step" or "next"?
> Right now, then I use 'n' it seems that gdb executes multiple assembly
> instructions and then stops. Sound like it uses the source level debugging.
>

Use stepi / nexti

Christian


> Any idea about that?
>
> Regards,
> Mahmood
>

Re: Question about disassembly

[Andrew Dinn]

On 11/03/2021 12:16, Christian Biesinger via Gdb wrote:
> On Thu, Mar 11, 2021, 13:07 Mahmood Naderan via Gdb <gdb@sourceware.org>
> wrote:
> 
>> Hi
>> How can I debug disassembly instructions with "step" or "next"?
>> Right now, then I use 'n' it seems that gdb executes multiple assembly
>> instructions and then stops. Sound like it uses the source level debugging.
>>
> 
> Use stepi / nexti
You will probably want to print the next instruction after each step 
which can be done using x/i $pc.

I use the following command definitions (added to my .gdbinit).

define si
   stepi
   x/i $pc
end

define ni
   nexti
   x/i $pc
end

regards,


Andrew Dinn
-----------

Re: Question about disassembly

[Andreas Schwab]

On Mär 11 2021, Andrew Dinn via Gdb wrote:

> You will probably want to print the next instruction after each step which
> can be done using x/i $pc.

You can do that with disp/i $pc.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: Question about disassembly

[Ruslan Kabatsayev]

On Thu, 11 Mar 2021 at 16:10, Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Mär 11 2021, Andrew Dinn via Gdb wrote:
>
> > You will probably want to print the next instruction after each step which
> > can be done using x/i $pc.
>
> You can do that with disp/i $pc.

Or, maybe even easier, use TUI. Namely, issue the command "layout
asm", and you won't need disp/i. (Press Ctrl-x followed by "a" key to
return to normal, non-TUI, mode.)
You may also find Single Key mode of the TUI useful. To use it, in the
TUI press Ctrl-x followed by key "s". Now you can step into
instruction by single key "i" (as if using "stepi"), and step over by
key "o" (as if using "nexti"). To exit single-key mode hit "q" key.
For more single-key commands see "TUI Single Key Mode" in the docs
[1].

[1]: https://sourceware.org/gdb/onlinedocs/gdb/TUI-Single-Key-Mode.html

>
> Andreas.
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
> "And now for something completely different."