8.0-current 200809 snapshot CD boot problem

[Peter Grehan]

Hi Marcel,

> o  I-cache coherency

  The culprit could be the code fragment in 
sys/boot/ofw/libofw/elf_freebsd.c:__elfN(ofw_loadfile),

         if (!strcmp((*result)->f_type, "elf kernel"))
                 __syncicache((void *) (*result)->f_addr, 
(*result)->f_size);

  If f_addr isn't the start of the text segment i.e. if the initial page 
wasn't included, then that is what is blowing up.


> Quick question: On ARM and ia64 you need to sync the
> D-cache before you can make the I-cache coherent. That's
> because the I-cache is made coherent with memory and
> not with the D-cache. How's that on PowerPC?

  Same - see powerpc/syncicache.c where the d-cache is flushed before 
the invalidating the i-cache.

later,

Peter.