plymouth doesn't support touch screens - Cannot enter full disk encryption passphrase on Lenovo Helix in tablet mode

[Donn Morrison]

Fresh install of 13.10, selected full disk encryption.

The Lenovo Helix turns into a tablet by detaching from the keyboard. If the system is rebooted while you are away from the keyboard (e.g., you leave it at home) you cannot enter the passphrase. I suspect this is or will become a problem for other tablets. I could not find any information about a workaround through searching except for storing a key on a USB stick and modifying initrd to read this at boot.

Obviously implementing an onscreen keyboard for the console at boot seems a bit far fetched. Is there any idea for a workaround?

Description: Ubuntu Saucy Salamander (development branch)
Release: 13.10

[Dimitri John Ledkov (xnox)]

One alternative is to only encrypt user-home directory, then your personal files are protected and will be decrypted upon login from lightdm, which does support touch screens.

Ideally plymouth would support touch-screen input.

Or we somehow include touch screen support into initramfs and/or alternative input methods.
E.g. using hardware keys that are present, e.g. "volume up/down".

Or create a small unencrypted install that lets you unlock/mount encrypted root and chroot into that....