I have a doubt about boot process, is possible set boot partition from boot if /dev/root fails? like a grub select. I prefer no use berryboot and my install is noobs based. My idea is set a boot partition failover for data corruption on SD card. Any ideas?
You need to edit
/boot/cmdline.txt and define
root=PARTUUID=, for example
You can have multiple partitions, up to 3 (except boot one), with different OS.
To find your destinated PARTUUID you can use this command:
ls -l /dev/disk/by-partuuid/
Each of rootfs partitions have to have own
/etc/fstab with its PARTUUID
You can prepare two folders
/boot/os2 with separated
cmdline.txt. Than just move content of needed os to /boot and it works just like full separated dual boot.
No. You could (I believe this is what something like berryboot probably does; I haven't used it) load a minimal root fs, possibly from an initramfs, present the user with options, and then switch the root filesystem (which is what initramfs kernels always do), but obviously there is a bit of work involved.
Alternately, you could write your own bootloader code, but this is even more work, and may require some proprietary knowledge (I'm not sure).