Re: GDB for Multiprocessor Architecture

["Amit S. Kale" <kgdb at vsnl dot net>]

Hi,

Making gdb handle multiple object images will be a lot of work. You can do 
something much simpler: Use multiple gdbs.

You'll have to implement multiplexing of serial connections used by them. A 
small program that listens to tcp/ip sockets for gdb connections on one side 
and uses the hardware probe on the other.
-- 
Amit Kale
EmSysSoft (http://www.emsyssoft.com/)
KGDB: Linux Kernel Source Level Debugger (http://kgdb.sourceforge.net)

On Wednesday 03 Dec 2003 11:58 pm, Andrew Cagney wrote:
> > Hi,
> > How can GDB be used to debug an application running on a chip that has n
> > number of similar CPUs. These CPUs share memories and run different code
> > images.
> > I plan to do a debugging session using the hardware probe and the GDB
> > remote protocol. My target does not have any OS support as Linux or
> > RTEMS but the host is a Linux box.
> > My question is how can I get to know that currently GDB is talking to
> > which CPU? Is it possible for me to do something like
> > gdb> load image1.o
> > gdb> CPU=1
> > gdb> |get register contents|
> > gdb> load image2.o
> > gdb> CPU=3
> > gdb> |get register contents|
> >
> > and such similar stuff.
> >
> > One way of implementing this is using the thread model but then each CPU
> > has altogether different code image to execute. Shall I have multiple
> > sessions of GDB, one per CPU? But again if a debug exception is raised
> > say a breakpoint is hit, how will I know on the host side which CPU has
> > hit the breakpoint.
> >
> > Has anybody done a similar task on any other target? Any help on this
> > fron shall be grateful.
>
> CPU's can be modeled using GDB's thread framework.  However, at present
> the model doesn't extend as far as modeling separate memory regions for
> each CPU (something that needs to be fixed).
>
> Andrew