Home assistant can be run from any platform that supports docker.
Kodi also has a headless docker container from Linuxserver.io
Docker is an incredible tool that allows you to run almost anything from a preconfigured container.
Use the dd command.
https://www.cyberciti.biz/faq/unix-linux-dd-create-make-disk-image-commands/
I also found this for booting from spi.
https://rhasbury.wordpress.com/2019/05/27/orange-pi-zero-spi-eeprom-based-nfs-boot/
If you have the ability plug a computer monitor into it, if it works it's settings on your TV. On my Roku if I remember correctly I had to set it to computer for that input.