PERFORCE change 132485 for review

[Peter Grehan]

> I'm planning this. I have done the same on ia64. It helps SMP, because 
> after you switched the BSP to its own stack kstack0 becomes available to start 
> APs on (in particular before you have the MMU set up)...
> 
> FYI,

  Great ! I would expect that some OFW calls may blow up with leakage of 
params on the kernel virtual stack instead of on the 1:1 stack, but that 
needs to be fixed anyways.

later,

Peter.