[OpenBIOS] ppc64 boot issues

[Andreas Färber]

Hello,

With or without the pending ofmem patches, ppc64 boot currently hangs  
after "Trying cd:,\\:tbxi..." (before "Trying cd:,\ppc\chrp 
\bootfile.exe...").
Symptom is, 0x700 program exception vector (not 0xfff00700) is being  
called with SRR1 pointing to some address that's neither in the low  
vectors range nor in OpenBIOS itself apparently.
I noticed that branching relatively to unexpected_excep from there is  
wrong and patched it to bctr there (which unfortunately appears to  
break 32-bit ppc64), but usually it does not manage to properly do the  
printk()

Here's what I found out so far:

* a breakpoint for bootinfo_loader_init() or so is not reached
* The "Trying" comes from (encode-bootpath) in forth/debugging/client.fs
* `debug (encode-bootpath) boot` does not return from open-dev
* `debug open-dev` does not return from path-resolution
* path-resolution gets called "endlessly" (5+ times single-stepping  
it), the hang occurred after successfully returning from some instance  
(after having successfully done so for a previous instance)

Does anyone have a hunch what might be going wrong? Or tips how to  
further debug?

Thanks,
Andreas