This guide by user  will show you how to install and update FreeBSD 11.0 on a Raspberry Pi machine. Follow the link below for the full set of instructions.

FreeBSD runs great on a Raspberry Pi, but the official images are all stable or current branches and there is no support for binary updates, i.e. freebsd-update. So I tried to figure out how to install the latest release version and keep it updated as well, without starting from scratch with a new image every time.

While it is possible to build a kernel and world on the Raspberry Pi itself, it takes about a week to finish (trust me, I tried) and you need a much larger /tmp on a disk or share for it to work in the first place. Since FreeBSD can also be cross-compiled, I decided to use my Xeon box to do the heavy lifting and then just install it on the Raspberry Pi.

Full tutorial: https://nerdazoid.wordpress.com/2017/03/15/installing-and-updating-freebsd-11-0-release-on-a-raspberry-pi/