Booting uConsole CM4 from encrypted NVMe

I have a uConsole computer and a new NVMe adapter for it. I’m not going to walk around with a terabyte of unencrypted data. That wasn’t an option. I found several good HOWTOs for booting a uConsole off an encrypted NVMe drive, yet none of them worked well on their own. Each left out one essential detail or another. This is my mashup of those instructions. For testing, I wiped my NVMe drive and started over, following these steps exactly, and at the end booted into a working system. I claim zero credit for any of these. Much of this is copied-and-pasted from the resources I list at the bottom. Those are the people who did the hard work of figuring this out. My goal was to put combine the working bits of each resource into a single document that includes the best of each. The gist of it We’re starting with a uConsole booted from its SD card. From inside that running system, we’ll partition the NVMe drive, encrypt most of it, copy the working system onto the new drive, and make the…