no real kernel patches needed any more. We use FILO and it brings up the IDE just fine, etherboot works well too.
Go to freebios.sourceforge.net to find the source tree.
To check it out:
cvs -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/freebios login cvs -z3 -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/freebios co freebios2