There are few commands in BootRom (screenshot).
It is necessary to fill the firmware to the switch through a COM port of the computer.
Switch: Extreme Summit 400-48T
Atftpd Server on Ubuntu 14.04
When connected to the switch does not go download the file, as if he did not see the tftp server. But when you connect through the console with all the other Linux successfully and the files can be seen.
It works in standalone mode
OPTIONS="--tftpd-timeout 300 --retry-timeout 5 /
--mcast-port 1758 --mcast-addr 126.96.36.199-255 /
--mcast-ttl 1 --maxthread 100 --verbose=5 /srv/tftp"