Previously on Ubuntu Planet, Matt Fischer described how to build Ubuntu Nexus7 images .   It did involve using simg2img & make_ext4fs binaries which you can get from:    android sdk  download hand compiled binaries from Matt's http server    But now, there are more usual ways as well:    Ubuntu Raring archive   Ubuntu Nexus7 Installer PPA for Quantal and Precise    It's the same PPA used in the current Nexus7 installation instructions .    sudo add-apt-repository ppa:ubuntu-nexus7/ubuntu-nexus7-installer sudo apt-get update sudo apt-get install android-tools-fsutils android-tools-fastboot   Enjoy and happy hacking the images =)   
a personal blog of Dimitri John Ledkov