https://bluegray.github.io/dual-boot-osx-and-ubuntu-16.04-with-encrypted-partitions.html
https://blog.jayway.com/2015/11/22/ubuntu-full-disk-encrypted-macosx/
http://thesimplecomputer.info/full-disk-encryption-with-ubuntu#explanation
https://iocrunch.com/2014/02/linux-dual-boot-on-mac-with-full-disk-encryption/