Question - How to use "readonly-root"

[john wendel]

In /etc/sysconfig, there is a configuration file named "readonly-root", 
that would seem to allow mounting the root filesystem read-only with a 
writable partition in tmpfs. I'd really like to use this on a little box 
I've built that boots from flash memory. But, I don't know what I need 
to do to move /etc and /var into a tmpfs.

Could someone who has this working post their "readonly-root" config 
file, or just some clues for us slow types?

Thanks.

John