OK, I see you said you have usb -> emmc adapter
make an image of present emmc, maybe on usb key on pbp
dd if=/dev/emmc of=/mnt/sda/emmc.img bs=1M status=progress
(if you don't have a big enough key, pipeline thru gzip,, as so
dd if=dev/emmc bs=1M|gzip >someplace, usb key,,emmc.gz)
Then, with adapter you easily restore any screw-up,
that is I am assuming you have another computer?
Then do a install (of armbian) on emmc,,,DO NOT shut it off
until you ALSO install pcm uboot to emmc (as last step before reboot)
See, with a partition copy install, fstab, boot.scr and probably the initrd need to be adjusted
Because those are all set for the SD
---
BTW,,,pbp reboot is flakey, do a shut off, reboot often hangs
make an image of present emmc, maybe on usb key on pbp
dd if=/dev/emmc of=/mnt/sda/emmc.img bs=1M status=progress
(if you don't have a big enough key, pipeline thru gzip,, as so
dd if=dev/emmc bs=1M|gzip >someplace, usb key,,emmc.gz)
Then, with adapter you easily restore any screw-up,
that is I am assuming you have another computer?
Then do a install (of armbian) on emmc,,,DO NOT shut it off
until you ALSO install pcm uboot to emmc (as last step before reboot)
See, with a partition copy install, fstab, boot.scr and probably the initrd need to be adjusted
Because those are all set for the SD
---
BTW,,,pbp reboot is flakey, do a shut off, reboot often hangs