.\configure --disable-jni --disable-gtk-peer --disable-gtk-gconf-peer --disable-plugin --disable-core-jni --withour-native-libdir -- with-ecj --host=ppc-amigaos --prefix/home/joakim/amiga/Projekt/cp093 --with-glibj=flat
Which build the whole thing using ecj (could probably use somthing else, but I had that installed), and creates a dir with class-files (not a jar file).
Anyways, trying to use this with JAmiga didn't work, and I believe there are a few native stuff needed. Will continue looking at what is implemented and not; info will come on the wiki.