suggestions on handling additional exception levels on ppc32

[Scott Wood]

On Mon, Apr 28, 2008 at 11:58:58AM -0500, Kumar Gala wrote:
> 
> On Apr 28, 2008, at 10:59 AM, Scott Wood wrote:
> >On Mon, Apr 28, 2008 at 10:40:56AM -0500, Kumar Gala wrote:
> >>A few possibilities:
> >>* introduce an additional function pointer as part of
> >>EXC_XFER_TEMPLATE() to specifies the type of handler (normal, crit,
> >>dbg, mcheck)
> >>* use the traps field low order bits to determine normal, crit, dbg,
> >>mcheck at run time.
> >>* duplicate the code paths for each exception level
> >>
> >>suggestions?
> >
> >You could temporarily disable all asynchronous exceptions, and use the
> >registers of the highest-priority exception type.
> 
> That doesn't work.  We have NMIs or will have them in the future.

Truly non-maskable?  Ick.  You could have a separate code path just for
the exception type that NMIs use, I guess, if there's a clear
highest-priority among the remaining interrupt types.  What sort of
exceptions are they?

-Scott