NetBSD on the Kurobox
From NAS-Central Buffalo - The Linkstation Wiki
This page describes how to get NetBSD working on your Kurobox (I only tested the Kurobox HG).
Steps to install are from http://www5.atwiki.jp/kuro-bsd/pages/168.html but I elaborated more on the details. Unfortunately I don't speak Japanese so I had to find some things out on my own.