Re: Using XML in GDB?

[Daniel Jacobowitz <drow@false.org>]

On Thu, Jan 26, 2006 at 03:06:27PM +0000, Andrew STUBBS wrote:
> That sounds good. We have been considering doing something with memory 
> mapped registers (devices, exception/interrupt reason codes, etc.), and 
> this might be the answer.

Would you expose them as registers, or as memory mapped I/O, from the
stub?  If the latter, what sort of information would you want GDB to
have about them, and how would you present them to the user or
frontend?

> Specifically, the data we need/want GDB to know about the target are as 
> follows:
>  - architecture variant (i.e. what registers and instructions are valid);
>  - endian;

While I'm not covering these at the moment, I do plan to.  Right now
I'm focusing on...

>  - non-core control/information registers;

... registers otherwise unknown to GDB.  Completely target-specific
features work too.

> None of this directly addresses the question of XML, but it does 
> represent the sort of thing (some) users are looking to do, and 
> therefore what 'extensibility' might entail. Of course, I'm still not 
> sure exactly what you envisage as the limits of the interface.

I'll be posting more about this real soon, I hope.  It's coming
together; I just wanted to have it a little more baked before I posted
it.

> Speaking of XML, are you aware of the SPIRIT SOC definition standard 
> (http://www.spiritconsortium.com) which contains some things that the 
> debugger might be interested in (and much in which it is not). I've no 
> idea how compatible they are, but it might be nice if GDB could pull 
> relevant information out of one of these.

I've vaguely heard of SPIRIT, but never any details.  Does it contain a
useful amount of information that GDB might care about?

I'm not going to pursue this for now because of IP issues; the terms on
the SPIRIT documents make me leery of using them for an open source
program, at least without talking to a lawyer about it first.

-- 
Daniel Jacobowitz
CodeSourcery