I can not reiterate enough just how easy it is to "clone" your modified emmc, or microSD card OS, ... into an image file that you can easily restore with (balena)Ethcher afterwards, and all withiin Linux.

 

1:/ you'll need a USB-card-reader-adapter.

2:/ no matter how your USB-reader card reader sees your emmc, microSD card, ..., it'll most likely be mounted on a /dev/sda1 partition.

3:/ sudo dd bs=4M if=/dev/sda of=~/tmp/armbian_odroidc4_11_01_2025.img
(you don't dd the partition, you dd the drive).

4:/ (optionally) sudo xz -v armbian_odroidc4_11_01_2025.img  
(this will take some time).

 

...and that's it, ... and you know the rest.

Edited January 12, 20251 yr by rin
spacing

Very cool. I didn't realize it could be that easy. Great (but potentially slow) for making backups.

Here's the "tricky parts" that I'm still trying to figure out...

- cloning a larger drive that only has part of it used to a smaller drive that has room for the used part.

- changing the UUID/boot info so that you can clone a µSD to the eMMC and still have it boot from either one.

Edited January 20, 20251 yr by Meestor_X

"tricky parts".

There is a topic on the forum re script to back up and shrink partition https://forum.armbian.com/index.php?/topic/29427-shrink-backup---a-tool-for-backing-up-sbc

That tool is great for backing up, but not doing the UUID/boot change I need. I have to see if I can find some documentation on how to copy and change the boot info as staring at the source code of armbian-install (where this is solved) is making my eyes hurt. 😉

Edited January 21, 20251 yr by Meestor_X

Can I not just dd a downloaded armbian image file directly to the emmc? i.e. put the image file in a folder on the µSD card or on an external flash drive and dd it to the emmc?

I tried that but it doesn't seem to work. I don't end up with a bootable emmc.

 

-EDIT-

NM. Stupid user error. I didn't decompress the image file before copying. Works fine once I do that.

Edited March 31, 20251 yr by Meestor_X

I was extremely excited to read this. My issue currently is that I'm dealing with S805 and H3 builds which had builds dominated by the megalomaniacal user whose name starts with "B" (really not a fan of their behavior but extremely impressive work). 
For some reason, these builds never come with the install.sh scripts that Amlogic builds normally come with, and I can only write S805 builds to eMMC using builds with the 5.7/3.10 kernel to eMMC because they come with an install.sh. I really want to "finish" the builds by writing them.
I'm hoping to use dd to write to the eMMC but it doesn't come up with lsblk at all (except with the 3.10 kernel).
Does anyone have any suggestions about how to get around this?

On 1/12/2025 at 2:31 PM, rin said:

3:/ sudo dd bs=4M if=/dev/sda of=~/tmp/armbian_odroidc4_11_01_2025.img

 

You forgot to mention a very important caveat, in that all filesystems on that device sda should be unmounted when you dd (BTW, pv is cooler than dd for this).  That means, you have to boot off a different device.

 

"sudo dd bs=4M if=/dev/sda | xz -v armbian_odroidc4_11_01_2025.img.xz" gets you the desired compression in one go.  | is called a pipe.