Re: DEFAULT CATCH!

[Ignatios Souvatzis <is%jocelyn.rhein.de@localhost>]

On Sat, May 02, 1998 at 06:55:52PM +0200, erik%mediator.uni-c.dk@localhost 
wrote:
> Will a kind soul please explain to me, what 
> 
>     DEFAULT CATCH!, code=FFF00300 at  %SRR0: FF80ADD0  %SRR1: 0000B070
> 
> is trying to tell me, and who is issuing this diagnostic ?
> 
...
> Running bmake in compile/POWERMAC results in a ELF-formatted 
> kernel in the file netbsd.
> 
> This file is then copied to a diskette and the G3 attempts to boot
> from fd:netbsd.POWERMAC (as the filename is).
> 
> After loading the file, the G3 says 'Loading ELF' and then immediately
> the Default Catch.

Sounds like the output of a default trap handler.

FFF00300 is a DSI exception, which occurs when a data memory access cannot 
be performed.

For these, SRR0 contains the effective address of the instruction that
caused the exception (FF80ADD0, in your case)

SRR1, lower half (bits 16-31, as numbered in PPC docs) contain bits 16-31 of
the MSR:

external interupts enabled, supervisor mode, FPU enabled, machine check
exceptions enabled, exceptions vectored through the table at FFF00000, 
mmu enabled for data and instructions, cpu is in big-endian mode.

        -is