Solved. Now booting lighttpd on an N3150 board.
DD'ing the lighttpd .iso image to a USB drive is odd too. On both machines
I get dumped into the grub shell.
For anyone else with the same problem: https://github.com/genodelabs/genode/blob/master/doc/release_notes-14-08.txt #L1105
BTW A serial connection is IMO absolutely critical for real hardware work.
Jerry.