HighPoint RocketRAID 2680SGL and FreeBSD
Solution 1:
HighPoint has not released documents or source code for a driver, but do provide an old binary distribution. It can be downloaded from their website. It's for FreeBSD 7.0, and others have reported it as broken for 7.2+.
It's probably not what you want to hear, but I'd recommend using a Adaptec or LSI based controller as they're both very well supported in FreeBSD (and every other OS).