Re: gdbserver version quandry

[Daniel Jacobowitz <drow at mvista dot com>]

On Thu, Nov 06, 2003 at 10:50:00AM +1000, John Williams wrote:
> Hi folks,
> 
> I have recently completed a port of uClinux to the Xilinx Microblaze 
> soft-processor architecture.
> 
> http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux.
> 
> I am now investigating providing gdbserver support for this architecture.
> 
> Xilinx ported gcc 2.95 and gdb 5.0 (20010428-1) to support microblaze - 
> as I understand it they have no intention of moving forward to a newer 
> version of gdb.
> 
> So, I think I'm stuck with porting gdbserver from gdb5.0, right?  I know 
> this is ancient history, but I don't think I'm about to undertake the 
> job of adding a new arch to gdb 6.0...
> 
> Some pertinent facts:
> 
> 1- Miles Bader, who did the v850 port of uClinux and gdbserver, has a 
> nice clean script and patch to morph gdbserver 5.1 to support uClinux.
> 
> 2 - The standard uClinux distribution supported by Snapgear, has a 
> hacked version of gdbserver 4.12.3 to support uClinux, but hard-coded 
> for m68k arch support only.
> 
> So, the question is:  Would it be cleaner for me to
> 
> (a) Back-port gdbserver 5.1 to support the gdb 5.0 interface;
> (b) Forward port and Clean up the m68k uClinux gdbserver 4.12.3 to 
> support the gdb5.0 and microblaze; or
> (c) Start from scratch with gdbserver 5.0 and provide microblaze support 
> directly?
> 
> I'm thinking (a) or (c), depending on how much changed in the 
> gdb<->gdbserver communication protocol between 5.0 and 5.1.   Is there 
> any online documentation on this - in particular regarding how it 
> changed from 5.0 to 5.1?
> 
> Superficially - Miles' scripts and patches don't apply cleanly to 
> gdbserver 5.0 - some file/directory structures have changed.
> 
> Any advice or pointers would be greatly appreciated.

I can't offer you any useful advice.  I didn't start seriously cleaning
up gdbserver until 5.2.

If your gdb 5.0 port supports remote debugging at all, then probably
easiest is to take the most recent version of gdbserver and work from
that.  Then adapt it to speak to your older client.  Not much should be
required.

Anything else is a dead end.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer