Re: gdb port project

[Ramana Radhakrishnan <ramana dot radhakrishnan at codito dot com>]

Hi Paul,

> 2.  I've searched around for multi-processing support within gdb, and I
> don't see much in the way of supporting debugging multi-processor
> systems.  Specifically, if a processor has multiple cores, is there any
> standard convention for gdb to support this?

As of now very minimal. Are they heterogenous or homogenous 
cores ? If these are homogenous cores then life should be 
slightly simpler since it would be akin to debugging 
multiple threads on an SMP machine and you might be able to 
get things working by defining the thread specific portions 
for the target right. With heterogenous cores there is some 
more fun in life :-P


> My initial idea was to have the proxy & ice support the multi cores, and
> have the ability of two instances of gdb to be started, the first
> instance would connect over tcp to port n, the second instance would
> connect to the second core on port n+1.  This way, 1 to n multi-cores
> could	 be debugged and controlled.  The downside is that there are no
> native multi-processor commands in gdb, for example, a run would cause a
> specific core to start running.  There isn't a method of issuing a 'run
> all' or a 'run group' to cause all the cores to or a group of cores to
> start running.  

One simple way forward might be to write a small
frontend on top of gdb that issues these parallelizing 
commands and  does this "process grouping" for you.  By 
keeping multiple GDB backends separately you can get around 
the process grouping issues. Then the extra stuff you need 
to do is to roughly implement some sort of IPC between GDB 
and the frontend.

cheers
Ramana

--- 	
Ramana Radhakrishnan
GNU Tools
codito ergo sum (www.codito.com)