Subject: Re: Duo 230 -the Continuing Saga
To: Richard Ervin <rervin@oasis.novia.net>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 01/07/1996 15:44:00
> 
> >> I was able to verify by writing some garbage on the screen that the
> >> booter starts to copy the boot code into low RAM, but never completes.
> >> If I only copy a small part of the buffer (say, 800 bytes) it will
> >> get to the next line (which is where I copy junk into the vram).
> >> If I attempt to write the whole buffer, however, it never finishes the
> >> copy operation.
> OK, this was due to the fact that I was using virtual memory.  Is there a
> way to force a particular application to *always* load into real RAM so
> I don't have to reboot and change the memory setting every time I reboot?
> Or how about  a way to disable virtual memory without a reboot?

The problem (as I understand it) w/ VM is not that the kernel doesn't
get loaded into real RAM, but that the PMMU table is jumbled when
we boot the kernel. The kernel expects to find a memory mapping table
showing full physical RAM, not a VM setup.

I don't see a way around rebooting if you need VM in your usual work.
But you could boot w/ extentions off (hold down the shift key). Thus
you wouldn't have to turn VM on & off.

Take care,

Bill