Boot multiple OSs on a single uSD card with PINN

[graysky]

A utility called PINN can allow you to have multiple OSs on the same SD card and boot from them at will. For example, for two ArchARMs, one aarch64 and another armv7h, This was asked several times before, for example here. It supports up to 8, the docs are a bit clunky to me but it's pretty easy to get working.

I have two physical uSD cards, one for aarch64 and another for armv7h. I ended-up using PINN on a separate card, installed "Arch2" which is armv7h and "Diet Pi 64-bit" just to get the partition schemes setup. I also added two projects which reserves space for others in the future. Once I had the install complete, I made tarball back-ups of my aarch64 card (one for boot and other for root) and of my armv7h card, then places them on their respective locations on the PINN card. After editing their respective /boot/cmdline.txt and /etc/fstab to account for the new partition schemes, I could boot to either at will. Very nice.

https://github.com/procount/pinn/blob/m ... ME_PINN.md

Better to avoid the GUI completely:
https://github.com/procount/pinn/blob/m ... -partition

Note that the first partition on the card is what the docs refer to as "the root directory of PINN"