Moin,
as an alternative to the ads-ltib-rpm hack, I can recommend the buildroot environment availble from
http://buildroot.uclibc.org/.
Check out the latest svn and (if you need it) my config from here:
http://caiaq.org/download...607-imx31lite.config
On a recently updated Debian/unstable box with gcc-4.1.2, you should be able to create a clean, uClibc and busybox-based EABI rootfs with < 10MB in total.
But please don't get back to me with endless compile logs of broken builts now - I won't care
Happy hacking,
Daniel