What I have done so far, which still doesn't work:
1. Flash new, clean Armbian image onto SD card, and boot from that
2. on the command line enter $ "sudo parted -l" which will show the device
3. on the command line enter $ "$ sudo fsck -y /dev/mtdblock0" which gave me the error ext2fs_open2: Bad magic number in super-block
4. on the command line enter $ "armbian-config", select System, select Install, select 7 Install/Update the bootloader on MTD Flash and wait, and this was successful (no errors)
5. reinstalled NVMe ssd, removed SD card, and it would not boot, reinstalled SD card and it would not boot.
6. Flash another new, clean Armbian image onto SD card, and boot from that
7. reformatted mtdblock0, here are the commands-
reddy@orangepi5:~$ sudo mkfs -t ext2 /dev/mtdblock0
mke2fs 1.47.0 (5-Feb-2023)
Found a gpt partition table in /dev/mtdblock0
Proceed anyway? (y,N) y
Creating filesystem with 16384 1k blocks and 4096 inodes
Filesystem UUID: fcdda797-0a6f-4dff-b3e1-49825625a26e
Superblock backups stored on blocks:
8193
Allocating group tables: done
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
8. ran armbian-config; Install to/update boot loader; Boot from MTD Flash - system on SATA, USB or NVMe I now get the following error
Warning
There is not enough free capacity on /dev/.
Please check your device.
9. I can Install/Update the bootloader on MTD Flash
Disks shows it as a 17 MB Block Device, contents unknown
GParted now shows the device as 16 MB, with 7 partitions that look ok, except filesystem is unknown
I can now reboot without a fresh armbian image, but still have to keep the SD card in the computer.