@aeva I worked on a commercial device that shipped with some PC software & the embedded device sources were just packaged on that CD.
There was definitely no feasible way for the customer/end user or even manufacturer to update that code without removing a bunch of silicone and soldering on a serial interface, but you know, "letter of the law". Back then I was just happy to be putting another penguin off the end of a production line.
Now, I am conflicted with a few decisions made above me.