You could use a `dd` command, to create a backup from the first device and then to restore to another. Be careful to not wipe partitions by accident. Another option might be creating a custom friendlywrt image (you can use github actions - see FriendlyWrt-Actions repo) with your changes and install ...

You need to flash it back. I think, a method with using RKDevTool should help. Take a look at https://wiki.friendlyelec.com/wiki/inde ... OS_via_USB

Maybe a firefly wiki will be helpful too: https://wiki.t-firefly.com/en/ROC-RK332 ... _emmc.html