download adbd.tgz and saucy-preinstalled-boot-armel-*.img for your subarch

boot into recovery mode and untar the adbd.tgz in /data/ubuntu

now reboot into bootloader mode and run:

sudo fastboot flash boot /path/to/downloaded/saucy-preinstalled-boot-armel-*.img && sudo fastboot reboot

after the device reboots you should have adb shell access after 10-20 seconds