friend recently asked me for recommendations for entry-level,
linux-based drones whose software is generated by yocto project, so it
could be used as a learning experience. as in, the fun would be in
the creation and customization of the software, not just playing with
the drone.

i didn't have an immediate answer ... i recall that qualcomm has
linux-based drone components:

https://developer.qualcomm.com/hardware/qualcomm-flight-pro

and i'm aware of https://www.dronecode.org/, focused on OSS drone
projects.

any thoughts on linux-based drones where one would build the
software using yocto project?

rday