In-place upgrades to eMMC?

Once I’m running Ubuntu on eMMC without an SD card, is there a way to re-install an updated version of my Ubuntu OS later from the command line?

The devices will be remote to me, no SD card available. The update would be available for download on a web site that the R5C could download it from to do a self update.

Is it possible? I’ve been doing that for many years using OpenWrt but need to run Ubuntu.

If it’s just a normal update, refer here:

image

In the meantime:

Sorry, it’s not what I’m asking about. I’ve updated my other post which also explains.
No access to SD Card, USB, nothing once the devices are installed in the field.
I can only work on them using remote software commands.

From that post;

My problem is, once these devices are out in the field, I will not have remote access to them anymore, no way to connect an SD Card or mount USB/Network yet I will need to upgrade the operating systems from remote.

I cannot allow the devices to get software updates in case that breaks something so the only thing we can do is keep updating our own build, and when that is ready, find a way to upgrade the remote devices.

Unlike OpenWrt where I can download the new image onto the device /tmp then use sysupgrade or mtd, how could it be done on these and while running Ubuntu? Meaning, in-place updates.

No tools are provided, you need to implement them yourself.

The block devices are operated by DD or MTD or emmc commands depending on the partitioning of Ubuntu. Finalize the upgrade.
https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R5C#Running_the_build

You can refer to openwrt’s sysupgrade command source code to realize the way:

So there is no way to do in-place upgrades if using ubuntu then?
I was thinking maybe add a partition that would be only used to store a new image to write from but that still doesn’t solve how the OS would upgrade itself.

If I changed over the openwrt, then I could do it using sysupgrade/mtd.

Is this what you are saying?