running netbsd from flash

[Greg Kritsch <greg%evertz.com@localhost>]

I'm trying to bring a NetBSD system up from a flash memory array, which for
the time being at least is read only.  I seem to recall seeing some FAQs
years ago about running with a read-only root partition, but I can't find
any current references to them.  Can anyone give me any pointers?  I just
got the boot working from flash the other day, and the problems seem to be
certain changes in /dev, and obvious problems with /var/run and /tmp.  Oh,
and the password database was a problem too I think.

My tentative plan is to union mount a memory disk over the affected
directories.  Has anyone done this and have any comments about it?  Does it
work?

Grgeory