C:\Android\android-sdk\platform-tools>adb shell
$ linux
linux
W: debian stable is already mounted. Entering chroot...
I: Executing /etc/init.android/rc_mount.sh
I: Entering chroot...
I: Executing /etc/init.android/rc_enter.sh
root@Galoula-ARMEL:/# alias
alias
root@Galoula-ARMEL:/# cd
cd
root@Galoula-ARMEL:~# cd test
cd test
bash: cd: test: No such file or directory
root@Galoula-ARMEL:~# bg
bg
bash: bg: current: no such job
root@Galoula-ARMEL:~# cp
cp
cp: missing file operand
Try `cp --help' for more information.
root@Galoula-ARMEL:~#
As you can seei managed to install Debian to the Arnova, it can be controlled via a terminal
I will try in the next days to find a stable ubuntu edition.