Re: GDB - create buffer to show information about CPU registers

[Augusto Fraga Giachero <augustofg96@gmail.com>]

I use emacs to do embedded firmware development for ARM Cortex M 
microcontrollers. Recently I've found an interesting python extension 
for gdb that uses the SVD (System View Description) files provided by 
the manufacturer: https://github.com/Palmitoxico/PyCortexMDebug (my 
patched version, the original repository is 
https://github.com/bnahill/PyCortexMDebug).
You can find the respective SVD file for your microcontroller here: 
https://github.com/posborne/cmsis-svd.

This extension provides detailed information of the peripheral's 
registers at the bit level. For now it can't write to the registers, but 
this functionality may be added in the future.



On 26-01-2017 09:42, Dan Čermák wrote:
> Thanks for the tip, I think that is everything that I need to get
> started!
>
> This solution even has the advantage that I can share it with other
> users who don't use Emacs but are still using gdb.
>
> Considering a 'less portable' extension: do you happen to know what
> would be the easiest way to create a buffer where the evaluation of
> these gdb macros would be shown? So basically to have a gui?
>
>
> Dan
>
> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> My currently biggest issue with my setup is, that to get some
>>> information from a register, I have to print its content with gdb (from
>>> inside Emacs), put that into the mate-calculator to find which bits are
>>> set and which are not and finally open up the datasheet of the CPU and
>>> look up the meaning of each bit.
>> I don't have a ready-made solution for you, but note that GDB
>> is scriptable.  If you look at Emacs's src/.gdbinit file
>> (http://git.savannah.gnu.org/cgit/emacs.git/tree/src/.gdbinit)
>> you can see what we do to help ourselves debug Emacs's C code.
>>
>> Note how you can use C-like operations in it, so you could code up some
>> .gdbinit file for yourself where you write some handy commands that
>> print the state of your devices's registers in a meaningful manner.
>>
>> Note that this is a "GDB-only" solution (the only Emacs part of it is
>> that you got the info in an Emacs discussion group, and that the sample
>> file provided came from Emacs's source code).
>>
>>
>>          Stefan