I've compiled a Linux image from the stock A80 Optimusboard SDK and created an Ubuntu 12.04 file system.
If you want to try it download the image from https://drive.google.com/file/d/0B99O3A0dDe67RWx5RXltVDJqcW8 and uncompress it and flash to your A80 Optimusboard. Then download the Ubuntu file system from https://drive.google.com/file/d/0B99O3A0dDe67WGRtM2RqSjd0QU0 and uncompress it and 'dd' it to an SD card. Insert the SD card into the board and power up the device. It will boot immediately into Ubuntu. For the first boot, enter 'depmod -a', set a root password and optionally resize the SD card ('resize2fs /dev/mmcblk1') and then reboot (default user is 'linuxium' with password 'p').
Wifi and sound works but ethernet is erroring at the moment and I haven't tracked down where the problem is yet.
Additionally you can then put the file system on the device itself by 'dd' the Ubuntu image to '/dev/mmcblk0p1'. You will then need to connect the serial UART cable and interrupt the boot sequence to set the parameter to boot from internal storage ('env set mmc_root /dev/mmcblk0p1' and then 'env save' followed by 'boot').
For a picture, please see https://plus.google.com/109451178006683865932/posts/CqvucYM3ig4