A while back I tried to install NetBSD/hpcmips on my 880. I could not get it to work, however I could get it to work with a copy from (if I remember correctly) 2004 or so.
I believe I used 2 CF cards, one for the loader and one to install the OS to. (If I did it today, I would partition it to have a FAT partition as well as the several NetBSD partitions.)
I can't fully replicate this because I put my (broken) 790's ROM in my 880 but I was stupid enough at the time to throw away the 880's ROM.
Does anyone know 1. why newer versions of NetBSD won't install correctly and 2. (slightly off-topic) if the SH3 version works/installs correctly on the Jornada 6xx series? I'm planning on getting a Jornada and I'd rather deal with BSD than JLime as a more modern alternative to Windows CE. (I'll still use CE!)