Re: [Crash-utility] Crash Subscription - Something Wrong
Dave Anderson wrote:
Piet Delaney wrote:
> Hi Dave [I moved]:
>
> I subscribed to your crash mailing list last evening and didn't receive
> anything yet.
> Looks like there was a posting today.
I remember approving your subscription request. Looking at the current
list of subscribers, I see these two:
Piet.Delaney(a)tensilica.com
piet(a)bluelane.com
> How much work do you think it would take to add the xtensa architecture
> to crash?
> From our IA64 work together I recall it mostly being the backtrace code
> needing work.
That's certainly a big part of it, but that's only the "gravy" that
needs
to be done after all of the foundational work is done. New architectures
basically require:
1. cloning the arch-specific parts of configure.c so that there
can be "#ifdef XTENSA" parts of the code.
2. creating a new "xtensa.c" file that satisfies all of the
requirements for the generic machdep-><architecture-data> and
machdep-><architecture-function> fields used throughout the
common code. The crash sources do contain a template PLATFORM.c
file, which is a bit dated and will most likely not have everything
needed, but it's a good place to start. You would basically copy
PLATFORM.c to xtensa.c, and then do a "s/PLATFORM/xtensa/" on the
file, and then start working on the specifics.
I'll start work on xtensa.c next now that configure.c seems to be fine.
3. in conjunction with step 2, satisfying all of the
"common" #define's
in defs.h.
4. After 1, 2 and 3 are done, update the Makefile to compile the
new file, and as it continually fails due to missing stuff, fix then
one step at a time.
5. At that point, you can start working on stuff like the backtrace
implementation.
Although -- now that I think of it -- none of the above will be worth
a damn without gdb support of the architecture. And gdb-6.1 certainly
doesn't have it unless it's a clone of some pre-existing architecture.
With your new crash 5.0 and it's use of gdb-8.0 that's no longer a problem.
So that's a whole other can of worms. Updating the version of gdb to
"merge" with the crash sources is yet another massive, always prone-to-error,
always finding-something-that-no-long-applies-anymore, situation.
Besides my maintaining a subscription to your mailing list I've created a
crash-xtensa
mailing list at linux-xtensa.org and an associated crash-xtensa-commits for logging the
git repository changes. Your welcome to be a list administrators if your interested to to
recommend when to push changes/patches to your repository.
Should be interesting but likely a rather slow effort; lots of other stuff on my plate.
-piet
Dave
> Some the the 'vm' command functionality would be helpful right now to debug
> a cache/tldb bug that I'm looking at.
>
> -piet