TFTP
From t-hack.com - Hack X300T / X301T
it is possible to enable the network boot by setting the jumper JP2.
Then a DRA file will be downloaded from a TFTP server at 192.168.1.200 or 0.0.0.0 ... this is hardcoded in the rom.
To use a custom DRA file, the signature check has to be patch as well, so this seems to be no better than the regular boot method.
More info:
http://www.t-hack.com/forum/index.php?topic=64.0 (in German)
