Hi. FreeBSD supports the Pi as a
Tier 2 (developmental) architecture. A few years ago I found this page on the FreeBSD wiki:
FreeBSD/ARM on the Raspberry Pi family. Although I have never used that information (the reason is mentioned in the next paragraph) it looks like it has been kept fairly up to date.
If you want a BSD system that supports your Pi board very well, you might also consider NetBSD. Board versions 1, 2 and 3 are currently supported by the official project (see the
evbarm port details for the Pi). The first generation should use the
evbarm-earmv6hf port variant. I personally have NetBSD running nicely on a Pi 1 model B (rev. 1.2).