Re: GDB --> Parallel Port --> Target??

[Andrew Cagney <ac131313 at redhat dot com>]

[adding Sachin]

> Andrew Batchelor <A.C.Batchelor-99@student.lboro.ac.uk> writes:
>
>
> > Hello, 
> >
> > I was wondering how straightforward it would be to write an extension
> > for GDB to use the parallel port to connect to a target instead of the
> > serial port?  (Changing only a few files?  Many files?  Which ones?,
> > etc.)
> >
> > Now I'm not really very familiar with GDB and before I jump in at the
> > deep end, I was wondering if any of you guys could give me any pointers?
> > At the moment I'm just having a read through the User Manual and the
> > Internals Manual and looking at some of the C files that look like they
> > might be of some help - can any of you guys point me in the right
> > direction?
> >
> > Any help or advice you could offer would be much appreciated.
>
>
> Have you tried simply doing "target remote /dev/lpt"?  It's worth a
> shot.

FYI, it should just work.  For GDB, there should really be no difference 
between a serial and parallel character interface.

> If it turns out that doesn't work because the parallel device needs
> special handling, that can be done pretty easily.  
> Someone asked about this regarding USB recently:
>
> http://sources.redhat.com/ml/insight/2003-q4/msg00016.html

The correct kernel driver will let GDB talk though to the USB connected 
device as if it was a normal serial device.

Of course, if it's the actual USB chip that your trying to communicate 
with, things can get a bit messy.  While having the USB chip include a 
pseudo-serial interface that talked remote-protocol would work, I've 
seen implementations that ended up having a debug agent translate remote 
protocol into USB primatives.

Andrew