I had tried that initially but it did not work and gave the same errors. Leigh Stoller wrote:
/tftpboot/freebsd and /tftpboot/frisbee workSo instead of /tftpboot/nos/freebsd maybe try /tftpboot/freebsd.nos for the path (change the DB too). That would confirm that tftpd gets cranky when you give it paths that it does not have in its config file. Lbs