Re: [Prex-devel] Educational use?

[Peter D. <pj...@cc...>]

On 2/11/2011 11:45 PM, Andrew Dennison wrote:

> Normally you would maintain a debug context for each process, and swap
> the debug context as part of the task switch - the OS needs to
> cooperate in this exercise. I've done this for some simple debug
> support using the hardware debug support in our target processor: I'll
> setup a gdb stub one day.

What I'm not sure about is how to get gdb to take advantage of that,
especially e.g. via the QEMU debug stub. On the other hand, I can easily
see how to create a couple of debug operations to allow one thread to
get/set another's registers, and to single-step a thread; given this it
should be straightforward to add a thread to a process which implements
the gdb remote protocol.

> I haven't played with qemu debug - I've only used qemu for some basic
> sanity checking that I haven't broken the architectures I don't have
> hardware for.

It's more useful if you're working with the PC platform. All the devices
are supported out of the box, plus there's no such thing as a JTAG port
on a PC :-)

-- 
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 Peter Desnoyers                                  pj...@cc...
 Northeastern Computer & Information Science