Go to the Columbia U. site and look at the howtos for
Linux and Xkernel-2.0. I believe the address is
ftp.ctr.columbia.edu   . You want dir
/pub/Xkernel/Xkernel-2.0-beta/linux-Xkernel
and I hope the stuff is explained in
Linux-Xkernel-2.0a.tar.gz
there. Good luck.

By the way, Sun's don't boot using bootpd. There's a similar
process that uses a combination ( with sun boot hosts )
of RARPD
rpc.bootparamd, and tftp.

Clarence