I figure out a set of --build=amd64 --host=amd64 --target=i686 toolchain. [1]
It seems work, with some problems left: 1. gcc64 depends on mpfr4/gmp/mpclib3, which has no multilib support yet. 2. I use dpkg-divert to replace the executable with this one. Is it suitable? It is in a very early stage. any suggestions is welcome. [1] http://mips64el.bfsu.edu.cn/debian-new/tarball/host64/
