I have a use-case for the Zymkey 4 with a Raspberry Pi 4B where the “pull the update over the internet” option is impossible, and the “store it on external mass storage” option is undesirable.
In the documentation and searching around the forums, I wasn’t able to figure out whether there was any way to store it in either the encrypted shared data partition of an A/B boot configuration or in an extra partition reserved on the microSD card.
I’m guessing that the shared data partition isn’t decrypted during the image update process and that the configuration process to create the A/B/data partitions would clobber any extra partitions that had been created to hold the update images. Is that correct? And is there any other way to do what I’m thinking?