Hi I am the foonas author. I recommend not using foonas/foonas-em for n2100 until the platform is listed as supported. Currently there is no ETA on support for this platform. Also foonas itself is still early days!
foonas-em will be available first (in flash repair/installation utilities), followed by foonas-iscsi (in flash dedicated iscsi only firmware) most likely later in 2008. After this foonas will be completed at some point!