Previously on Debian Jesse on Raspberry PI, I did a solution that was booting the system from one of squasefs images and overlayfs in the second partition (and alternatively boot to "main" system inf boot from the image wasn't successful). That worked quite ok.
Now I'm trying to do the same functionality on Ubuntu Focal. I did come across information about the Ubuntu Live system, but I'm stuck with a lack of information and examples. Maybe I'm just not looking in the right places. One of the different thing is that with Ubuntu there is an uBoot config, that I didn't have any experience before today.
Is there available more information or examples on how to define where I can load sqashfs image? In my old solution, I did a small initramfs script, that mounted partition with images into /run/images, remount squashfs image as the new root partition, setup overlayfs, update /ets/fstab on suqshfs overlay filesystem and continue boot into "new" system.
I think that Ubuntu Live is doing most of those things, however, I can't figure out how to actually set and boot into squashfs system. Am I wrong in my assumptions?
I will be very happy for any pointer to documentation or maybe an example.
Best regards Uros