Patch to partially boot an EFIKA

[Peter Grehan]

Hi Andrew,

> The attached patch helps me to partially boot my EFIKA. The file
> ofwread.S is from NetBSD and needs to be placed in sys/powerpc/powerpc.
> 
> The patch takes the real-mode ofw interface code from NetBSD and the
> TLB exception handlers from //depot/user/jaras in perforce.

  I can probably put in the exception vector stuff, de-camel-casing in 
the process.

  For ofwread.S, I have a slightly different solution that is needed for 
the G5 that I think will also work on the EFIKA. Plus, it's written in C 
:) There's a bit of extra code around it but hopefully I'll get it done 
soon.

later,

Peter.