fwup

That's the general wisdom I've seen. I work on the Nerves project which does Elixir on top of Buildroot and there we use fwup (https://github.com/fwup-home/fwup) which does a very nice job of a lot of this. Including signing, hashing and more. This is a real example of a config: https://github.com/nerves-project/nerves_system_rpi4/blob/ma...

I’ve been using fwup (https://github.com/fwup-home/fwup) in embedded Linux consumer products for almost 10 years and it has Just Worked. Supports A/B updates, uboot integration, and signed update files. Not sure about buildroot, but in Yocto it’s fairly straightforward to write an image creation recipe that bundles your ext4 filesystem image(s) into an update file you can deploy.

> Bare metal management really feels like an unsolved problem. Whilst everybody working with cloud environments is whisked away by the latest shiny tools like Docker and Ansible, those of us working with bare metal are still trying to find a way to keep machines up and running with an OS that doesn't get corrupted from unexpected poweroffs or permanently cut itself off from the network because of a bad config. It is and isn't solved. It usually takes a lot of work or custom scripts. One of the best is the Nerves Project, and is what I use for IoT deploymens [0] or even simple cloud deployments. Nerves is setup to run Elixir/Erlang, but it's really just a wrapper around buildroot and Elixir can start programs in any language desired with some work. One of the core authors wrote a tool called `fwup` for doing immutable updates on Linux [1].

Not familiar with TinyCore myself, but I’d recommend trying Nerves Kiosk if a webpage kiosk is your primary goal [1]. Getting all of the FS settings right and a tuned system like daviduum talks about is tricky IMHO. Though it should be possible with Yocto Linux or similar as well I’d imagine, especially with ‘fwup’ or similar in the loop. Nerves uses ‘fwup’ [2] to create a R/O squashfs filesystem for the core OS image which is also highly compressed. 1: https://github.com/LeToteTeam/kiosk_system_rpi3/blob/master/... 2: https://github.com/fhunleth/fwup

It's not a full OTA solution, but fwup (https://github.com/fhunleth/fwup) handles the packaging and application of Linux firmware update images quite well. Apache licensed, supports A/B updates (see tomc1985's comment), Ed25519 digital signature verification, and u-boot support.

In addition to the other great projects mentioned, I'll throw out fwup [1] (A/B partition update, used by nerves.io) and snapcraft [2] (containerized packages, not whole-OS.) For myself, I'm comfortable with some form of A/B partition update (assuming the problem of distribution and verification is solved elsewhere) however at the very least you still have to patch or script u-boot (or your bootloader of choice) to make it smart enough to try booting the primary partition and also have some sort of canary file it can check on the next boot to validate that the partition booted successfully and e.g. made it all the way to the target runlevel. And if that check fails fall back to the secondary partition or some recovery image. Embedded firmware updates - especially for M2M devices that are not necessarily user-facing - are sort of like cha

From the same Nerves project I had founnd this: https://github.com/fhunleth/fwup It is a firmware updater. It seems one mode is the basic create whole disk image and replace. The other is can handle update "tasks". Now in general Erlang was built to handle hot-code updates. Basically replace the code while the code is running (have use immutable data structures and have specials facilities built it). But that can be tricker to set up and if you have C code or hardware control, it might not work as well. So upload firmware then reboot might work (I am just guessing here since I don't know any details or goals).