Debian pkgs in ROMs?

[Roger Flores <roger@tapwave.com>]

This isn't a strictly ARM question, but so many ARM devices are embedded
that maybe the answers are known.


1. How are people using Debian in devices running from ROM?  We're
working on an ARM device with a 8MB ROM.  I want to enable adding
Debian's precompiled packages at runtime.  I've setup debootstrap on an
NFS mounted partition, but it's HUGE!  No way will it fit in ROM!  I
really only want dpkg and apt-get, and their dependencies.  Is there a
web page somewhere describing this?  Has anyone done this?  I played
around with installing arm packages to a rootfs on my i386 desktop using
dpkg's root directory option.  The idea was to ultimately put that in
ROM, but dpkg goes crazy without (undocumented?) config files being set
up in that root directory system.  I wish it would just create defaults.
Why is this so hard?

2. How do people inform dpkg that certain package equivalents are
available?  We have tuned jpeg and SDL substitutes.  Installing a
generic one is the wrong thing to do.  And we use busybox.  Did I miss a
doc describing how to do this?  Is Ubuntu kind of doing this with their
"funny" versions?

3. Another issue is that some packages are likely to be in ROM and
others in a ramdisk.  We're thinking of using something like Unionfs to
merge the two.  Will there be a problem updating packages?  


Thanks,
-Roger