Technically arm64 builds are possible already. We’re waiting for upstream changes that would make automated builds feasible.
We use https://www.piwheels.org/ for pre-compiled binaries for python libraries that use C code. They don’t support ARM64 yet, and without pre-compiled binaries, our automated build times jump from <10m to >1h. (ARM emulation on AMD build servers is slow)
If determined and reasonably familiar with Docker you can build images from source on your Pi. This will take a while, but be significantly faster than our build server.
Edit: it’s been a while since we actually tested it, so I fired up CI builds for the two repositories that would suffer most:
At time of writing, the history build is still running, but results are much better than expected. Apparently availability of ARM64 wheels on PyPi has improved since our last attempt. The Spark service build “only” took 20m. (~18 of which spent on ARM)
The Spark simulator is another story entirely, but if other repositories show comparable results, we’ll likely make the switch, and add ARM64 to the supported architectures.
Edit 2: it looks like ARM64 added ~10m to both the devcon-spark and history builds. That’s not too bad.
ARM64 is also supported by all of our base images (python, mosquitto, influx, node, redis, traefik, nginx, alpine, node-red). I’ll flip the switch for the develop builds, and do some testing on a Pi4. If that doesn’t yield any big problems, ARM64 will be supported in the next release. Firmware simulator support will likely be added at a later date - building the ARM32 version already is a pain.