Ubuntu system for mobile phones has been released on the 17th of October, 2013..

How To Install Ubuntu Touch On Your LG Nexus 4 Smartphone
Ubuntu system for mobile phones has been released on the 17th of October, 2013. It  is far from being a mature and stable mobile operating system, but if you have an unlocked LG Nexus 4, you can test it anyway.


Before we start, do the following on your Ubuntu Desktop system:

$ sudo add-apt-repository ppa:phablet-team/tools
$ sudo apt-get update
$ sudo apt-get install phablet-tools android-tools-adb android-tools-fastboot

Next, set your phone on development use by going to Setting -> About Phone and tapping the Build number 7 times, until you get a message.

Next, enable the USB debugging from the Developer options, that appear in the new menu and accept the paring.


Before you install Ubuntu Touch on your Nexus 4 device, backup your Android system with the following command:

$ adb backup -apk -shared -all



Next, install Ubuntu Touch with this command:

$ sudo phablet-flash ubuntu-system --no-backup


Do not stop the process or close the terminal until the device boots with Ubuntu Touch.


When you will need to restore the Android OS, just do:

$ sudo adb restore backup.ab


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Ref: http://linuxg.net/how-to-install-ubuntu-touch-on-your-lg-nexus-4-smartphone/