Subject: Re: Kernel doesn't probe memory size correctly...
To: None <port-pmax@NetBSD.ORG>
From: Michael L. Hitch <mhitch@lightning.oscs.montana.edu>
List: port-pmax
Date: 05/07/1998 11:00:41
On May  7,  5:51pm, matthew green wrote:
> 
> in joel's 5000/240 (we work together), the prom correctly identifies
> the memory.  `cnfg 3' shows them being 2x32 and 4x8..  if the prom
> correclty handles it there, i imagine it handles it all OK.  looks
> like a bug in NetBSD to me.

  From this description, it would look like the 8M modules are appearing
multiple times (i.e. 4 times) in the 32M address space for each memory
slot.  The NetBSD probe just checks each page to see if the memory can
be written and read back correctly.  It stops the memory probe when a
compare fails or if a BUS error is signaled.

  If the 8M memory really appears 4 times in the 32M slot, then the
memory probe needs to be smarter.  It would need to know the size of
the memory in the first slot, and on each successive slot, it would
need to specifically check for smaller modules that appear multiple
times.

Michael

-- 
Michael L. Hitch			mhitch@montana.edu
Computer Consultant
Information Technology Center
Montana State University	Bozeman, MT	USA