Yeah back with 1.14 or so I set up some cross (and native) toolchains for mipsel with the intent of putting some stuff on my ER-X. While it was a giant pain in the dick with the unsupported version of Debian Ubiquiti was using, it was doable. Cross compiling on Debian has come a long way (altho I'm using crosstool-ng on OSX these days which is fairly slick).