[OpenBIOS] Sparc64 OpenBIOS

Tarl Neustaedter Tarl.Neustaedter at sun.com
Wed Nov 18 19:24:44 CET 2009

Nick Couchman wrote:
> [...]
> So, for some reason, it cannot step into read-disk for debugging.  If I do "see read-disk":
> 0 > see read-disk 
> : read-disk
>   dup >r 0 swap cif-seek if
>   " seek failed" die tuck swap r> cif-read <> if
>     " read failed" die
>   ;
>  ok
> And, all of these seem to be primitive words - e.g. swap, cif-seek, etc., cannot be debugged.  I would guess "cif-seek" is where it's failing, which looks like this:

These are part of the forth kernel, where it does file handling 
operations - they eventually end up generating reads to the HBA.

Where you are in the code itself - line 209 of:


So we're doing the first cif-seek, which is the client-interface seek. 
See section in IEEE 1275. That causes the disk to be read so you 
can cache disk accesses. The question is whether the arguments we are 
sending are reasonable. What we saw:

00000000ffe318e0: dev-ih  ( 8008000 800 8000 ffe4d358 ) 
00000000ffe318e8: read-disk 

Those arguments we see on the stack are adr, len, off, ihandle. ffe4d358 
is a reasonable address for an ihandle. 0x8000 is a reasonable byte 
offset into the disk to read - and that's all that seek takes (the adr, 
len get used later by the cif-read, which we don't reach). So somehow, 
trying to byte offset 0x8000 on the disk is failing - don't know why.

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