CONFUSÃO POSSÍVEL:
O comando adb root simplesmente recarrega o daemon adb (como root) no seu desktop PC . Isso lhe dá maior privilégio (se necessário) para acessar e controlar o dispositivo conectado.
Isso não é 'root' para o dispositivo. Isso NÃO afeta o dispositivo (ou seu firmware).
Quais etapas você concluiu?
O procedimento de instalação (manual) tem apenas 5 etapas: ( por exemplo, para Nexus 7 )
Arquivos de imagem de: link
ATUALIZAÇÃO: (2013-jun-14)
Current daily is now Saucy (13.10) (early BETA)
To stay with Raring (13.04), use: http://cdimage.ubuntu.com/ubuntu-touch-preview/raring/monthly-06/
/ UPDATE
[1.] Check device is attached
adb devices
* daemon not running. starting it now on port 5### * * daemon started successfully * List of devices attached ############## device
[2.] Load machine-specific image (eg. for Nexus 7/grouper)
adb push ~/images/raring-preinstalled-armel+grouper.zip /sdcard/autodeploy.zip
#### KB/s (######### bytes in ##.###s)
[3.] Reboot to Recovery Mode (and run autodeploy.zip)
adb reboot recovery
[3A.] (OPTIONAL) Repeat previous step: Reboot to Recovery Mode
Note: As the device may not be stable (until after step 4), this places device in a known state while waiting the 2-4 minutes for load to complete.
adb reboot recovery
[4.] Load ubuntu-touch (phablet) image (for ANY supported device)
adb push ~/images/raring-preinstalled-phablet-armhf.zip /sdcard/autodeploy.zip
#### KB/s (######### bytes in ##.###s)
[5.] Reboot to Recovery Mode (and run autodeploy.zip)
adb reboot recovery
The device should reboot to Ubuntu Touch (phablet) GUI