This is on the docker registry as quay.io/alexeyraga/ghc-arm-7.10.2.
To use, mount your GHC source code into /home/ghc
docker run --rm -i -t -v `pwd`:/home/ghc quay.io/alexeyraga/ghc-arm-7.10.2 /bin/bash
You are now ready to compile GHC!
To cross-compile use cabal-arm command
I've found that cabal-arm init creates a project that has a dependency on base < 4.8 while the "current" base was actually 4.8 so I have to fix it manually in a *.cabal file.