I've build Android in Ubuntu 13.10 as per the wiki
http://wiki.radxa.com/Rock/Android_Build, and flashed the image with upgrade_tool:
./upgrade_tool uf rockdev/update.img
It failed to flash at first, as it could not find the board, but trying this morning again it worked.
Now at boot time, it will show the animated "radxa" logo forever, and continuously show the following messages in the serial console:
[ 624.645119] init: untracked pid 26951 exited
[ 624.663920] init: untracked pid 26950 exited
[ 629.462119] request_suspend_state: wakeup (0->0) at 629440280410 (2014-01-16)
[ 629.464642] init: untracked pid 27167 exited
[ 629.478298] init: untracked pid 27166 exited
[ 634.562433] request_suspend_state: wakeup (0->0) at 634540587452 (2014-01-16)
[ 634.565668] init: untracked pid 27383 exited
Have you tried a recent build from git? Or have you experience this issue before?