arm access to stack slot out of allocated area

[Olivier Hainque]

Hello Ramana,

> Olivier, while you are here could you also document the choices made by
> the vxworks port in terms of the ABI and how it differs from EABI ? It
> would certainly help with patch review.

Thanks for your feedback as well.

Yes, I'll add a comment and macro defs to the VxWorks
headers to state the ABI settings explicitly.

We're using the defaults from arm.h for vxworks6 today
(ABI_APCS & MASK_APCS_FRAME), which matches what the system
environment provides.

I'll stick a note mentioning the deprecation Wilco
described and pushing towards VxWorks 7.

We'll probably end up removing support entirely at
some point.

Cheers,

Olivier