On Thu, 23 Aug 2001, Greg Ingram wrote:

> Rats!  Well, how hard would it be to instruct the kernel not to use the
> memory in the second slot?  It *seems* like it shouldn't be too difficult
> and I might then be able to use 32 of my 40 megs.  This sounds like a

  It shouldn't be too hard to modify the code in machdep.c to leave out
the bad memory area when it loads the memory into the VM system.  It
already loads two different lists (a lower priority list that devices that
are limited in DMA capability can use to steal memory from, and the normal
list).  Since the first segment is 8MB, it looks real trivial to just
modify the second uvm_page_physload() to start at the 16MB address instead
of the 8MB address, which would skip the second memory slot if using 8MB
modules.  You would still need to have a memory module in that slot
though, otherwise it would only see 8MB of available memory.

  As of today, the -current sources will support non-contiguous,
mixed-size memory configurations on machines that allow that support.
This would allow you to use all of your memory no matter which slot its
plugged into.

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