Building an Ubuntu rootfs isn’t that complicated if you know how to use qemu.
Let’s start with a 16.04 arm64 image.
First you’ll need to install qemu-user-static on your Ubuntu Host PC.
sudo apt-get install qemu-user-static
Download the rootfs image.
Note: xenial is currently beta, so don’t use it for production systems (as if you’re using your TX1 for anything besides development at this point).
Extract the archive as root because all the files need to be owned by root.
sudo tar -zxvf ../xenial-core-arm64.tar.gz
Copy the aarch64 qemu executable to the rootfs. You’ll need this for chroot.
sudo cp /usr/bin/qemu-aarch64-static usr/bin
You won’t be able to use dns without copying your resolv.conf file. The host resolv.conf will do.
sudo cp /etc/resolv.conf etc/resolv.conf
Now chroot. Don’t worry your system knows to run qemu now.
sudo chroot .
Now run apt-get as you normally would.
apt-get install ubuntu-desktop
I’m going to try to boot my new rootfs as soon as I get my board(which is currently on backorder), so I’ll let you know how it works out.
Next I’ll try a 4.5 kernel.