you can create it by yourself with lxc in ubuntu
install lxc in ubuntu and after create a debian (jessie) container aarch64 ( template download )
after you can tar.gz the container with all permissions and extract in shield tv instead of the ubuntu version provided by me.
sudo lxc-create -t download -n u1
you will have a menu to select debian - jessie - aarch64
when I run this on my laptop/bunsenlabs, I do not get options for debian jessie aarch64
I suppose you mean I should run it in ubuntu once installed on my shield, right?
thanks a lot.