Updating from chroot

[Jonathan Berry]

Hi all,

I have my test system setup on a partition along side my normal use
FC4 install.  The partition gets mounted in FC4, and I found I could
do some stuff in the FC5T2 (Rawhide) environment (eg rpm -q stuff) by
chrooting into the FC5 partition.  What I do not know is what all I
can successfully do in the chroot environment and what things should
be done to get a more fully working test system running in chroot (eg,
/dev/ is basically empty).  Specifically, it would be nice to do a yum
update from within the chroot so I don't have to reboot to the Rawhide
install, update, wait forever for updates to download and install
since I have not updated in a while, reboot to the new kernel, etc. 
Can this sort of thing be done safely (correctly) from within the
chroot?  Can I do stuff like start up udev so I can access hardware?

Jonathan