Re: [PATCH] New port: ia64-*-freebsd

[Daniel Jacobowitz <drow at false dot org>]

On Mon, Jul 25, 2005 at 10:32:27AM -0700, Marcel Moolenaar wrote:
> >  That's where I get confused.  How is
> >the data in the core file mapped onto the memory space?
> 
> I'm not quite sure I get your drift. Let me just answer what I think
> you mean:
> 
> The backing store is nothing more than a second stack. The first being
> the well-known memory stack onto which (stacked) local variables live.
> The backing store grows upwards and the memory stack grows downwards.
> So, in essence, it's a mmap'd region. Either created by the kernel when
> the process is created, or created by the threading implementation.
> In the core file the backing store is part of some loadable segment.
> Either by itself or part of a larger block of memory.

No, that's not what I mean.

Here and further below you think I'm talking about the concept of the
target object.  I'm not.  I'm talking specifically about the corefile
implementation you included.

That implementation reads from an address in memory to find the
registers.  If there's no room for them in memory, where the heck are
they, and how can you find them by reading from memory?

> >I really recommend fixing your notes first and not making GDB support
> >this scheme.
> 
> I've thought about it. The point is that GDB already needs to support it
> for Linux, so splitting up the work in such a way that FreeBSD 
> temporarily
> has the same "limitations" as Linux seemed ideal. Not only is it 
> possible
> to improve the overall core file support in FreeBSD, it also allows 
> Linux
> to move away from the abstraction. In that sense, the abstraction is
> gradually moved out of GDB. And as for any interim solution: there is 
> bound
> to be some icky code for a while.

So the answer to my above question is "you can't yet"?

> All I can say is that I'll think about it: The FreeBSD release schedule 
> is
> now in my advantage, but getting binutils to grok a whole new kind of 
> core
> notes may by itself turn out to be... euh... challenging... :-)

Actually it's quite easy.

-- 
Daniel Jacobowitz
CodeSourcery, LLC