ppc multlibs and BSP removal was Re: powerpc altivec support

Sergei Organov osv at topconrd.ru
Mon Feb 14 10:39:57 UTC 2005


Eric Valette <eric.valette at free.fr> writes:

> > As for the r2/r13 loading by the new exception processing code, sorry,
> > but I leave it as an exercise for those who believe new exception
> > processing is better than the old one.
> 
> I still do and still believe you don't get it but anyway as you only use one
> platform, you cannot see how old execption code is broken...

I use 3 platforms, MPC509, MPC565, and MPC8260, quite happily with the
old exception processing code. What is broken is the new exception
processing due to its silly design choices. The main problem about it is
maintenance nightmare.

> > Let them change at least 5 separate files with almost identical
> > code. Well, if somebody believes something is inherently broken with
> > such an approach to the software development, ask Eric Valette about
> > it, or just read what he answered to a similar question before:
> > <http://www.rtems.com/rtems/maillistArchives/rtems-users/2002/november/msg00167.html>
> 
> > If you use new exception processing, better make sure no code in your
> > executable tries to change r2/r13 even temporarily while interrupts are
> > enabled. I prefer to be on the safe side, so I stay with the old one for
> > now.
> 
> Yes. At least you eat your own dog food. That's fair. Try to implement a
> debugger with old execption processing or separate execption handling
> (processor dependend) and IRQ handling (BSP dependend) as an exercice.

If *you* need an exercise, take a look at how it's done elsewhere. If
you don't find a good example in RTEMS, take a look at another free
RTOS. Believe me, you are not the first programmer on the Earth trying
to solve these problems. What I see is that your reinvented wheel is
somewhat rectangular, sorry.

-- 
Sergei.




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