Jashank Jeremy wrote an article on using FreeBSD, ZFS, GPT, and UEFI, on a 64-bit system.

Apparently, the trick to is to use GRUB’s kFreeBSD mode. Full information here:

Hmm, WordPress imbeds the entire source file listing of a Git.Github URL. So I’m splitting this URL, you’ll have to combine it yourself:

https://
gist.github.com/jashank
/9ec2f72126552068434c

Also check out the reply from Felix Khrohn on Jashank’s Twitter post, with an URL to alternative method by Ganael Laplanche.