Install Armbian to NanoPiNeo eMMC

You will find suitable Armbian images here: https://www.armbian.com/nanopi-neo/

We suggest you go with the Minimal/IOT image

Use any preferred Etcher or "dd" to write it to a SD card. Boot system from SD card. (You might actually use any bootable SD card containing Linux at this point) Make sure you have a running ethernet connection.

Login as root.

apt install xz-utils

The magic pipe:

wget -q -O - https://dl.armbian.com/nanopineo/Bookworm_current_minimal | xzcat | dd of=/dev/mmcblk2 bs=1M status=progress

poweroff

remove SD card and restart from eMMC. It is advisable to monitor boot process via USB-C port (115200 baud)

Enable required overlays by using armbian-config or add them manually to /boot/armbianEnv.txt

You need:

overlays=i2c0 uart1 uart2 usbhost1 usbhost2