Your only serious consideration is netBSD, as
you've found out.
Linux's roots were x86 so it hasn't been ported to nearly as many
platforms.
NetBSD's roots were in x86 too; it's just put a lot more work into
curing that. :-)
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B