I created a Debian 9.5 “stretch” OS build for the Avnet Ultra96. This build is running a 4.14.72 mainline kernel with Xilinx additions for the ZynqMP.
The image fits on a 4GB sdcard. If you want to use it on a larger card, flash the 4GB image and run the script “expandfs.sh” after boot and the partition will expand.
The USB 3.0 port is configured as a network device with IP address 192.168.0.2. Plug it into your PC and ssh to this address.
Wi-Fi will appear as an access point with SSID “DROIDIFI” and no security. If you connect over Wi-Fi the device address is 192.168.0.1. Edit the file /etc/network/interfaces.d/wlan0 if you want to use it as a Wifi client.
There is no root password.
No HDMI GUI (need Vivado 2018.3 to add this)
Reboot causes halt (must power cycle to reboot)