On 1/30/07, Michael Lorenz <macallan@netbsd.org> wrote:
> issue on my iBook so there isn't much I can do about it. The problem
> appears to be that interrupt are enabled too early for some reason.

on that subject, in case you find it interesting, the following link
talks about decrementor exceptions, etc (it is in relation to linux,
but may be of conceptual relevance... in that the decrementer
exception with srr0 = 0000000 is ok, but rather that when interrupts
are enabled, there should, by that stage, be exception trapping things
already installed...

http://sources.redhat.com/ml/ecos-discuss/2001-04/msg00014.html

the text excerpt is as follows:

"... the decrementer exception?
This is a common thing when starting up an MPC8xx processor. The decrementer
will start decrementing as soon as the clocks are set up, and since it is
initiated to 0 at reset, it will trigger a decrementer exception as soon as
the interrupt disable bit is cleared in MSR.

I guess that is common knowledge, so I'd rather find out why there isn't
any code in the exception vector area to handle this exception. Maybe
the interrupt prefix bit is modified in MSR by mistake? How is your MPC
configured at reset (I mean the reset configuration on the data bus)?"

leon.