PERFORCE change 132485 for review

[Rafal Jaworowski]

Hi Peter,

>>     Temporary fix to avoid confusion of 'kstack0' symbol and make e500
>>     kernel operational again. kstack0 area requires further
>>     improvements (space for kstack0 is now statically defined within
>>     kernel body, does not have guard pages etc., which should be fixed)
> 
>  On AIM it is allocated correctly but never switched over. The
> (not-yet-implemented) plan was to mimic amd64 and return the value from
> powerpc_init() to locore, switching r1 to this value before calling
> mi_startup().
> 

Thanks for the hint, I'll look at amd64 more closely. So the idea is to switch
over to thread0's kstack immediately before mi_startup(), so that temp stack
we were running on can be recycled etc. right?

Rafal