>>337
http://www.freebsd.org/cgi/cvsweb.cgi/src/UPDATING?rev=1.342.2.36&content-type=text/x-cvsweb-markup&only_with_tag=RELENG_5

20000911:
The random device has been turned into a (pseudo-)device,
rather than an option. The supplied kernel config files have
been updated. You will need to do something similar in your
own kernel config file.
Remove:
optionsRANDOMDEV
Add:
devicerandom
If you prefer to load the loadable module, you need to do
nothing.

これジャマイカ？
/usr/src/UPDATINGを読めってことですね。
(>>337が示したリンク先でもそう結論付けてるし（笑）)