[VLM]

Roll back the tech level and go vertical silo.

The auto industry buys bolts and makes pistons because the marketplace can't make pistons, roughly. They have the know how if the bolt marketplace collapsed to turn steel rod into bolts, maybe not as easily and cheaply as it can be done now, but if the bolt market died they'd make their own bolts.

The commodity microcontroller is dead. My guess is crappy "homemade" older-gen FPGAs made by GM for GM products will be the future of automotive ECUs and other automotive apps.

In 1980, $100M built you an entire fab. It costs GM about $300M to remodel an old assembly plant. They can either go out of business because 2022 chips are unavailable or build their own fab. Hmm I wonder what they'll do?

The nice part about building an older gen FPGA is it quite accurately emulates an older gen chip, usually using a lot more power and requiring a lot more silicon, but at least it works better than "next estimated shipping date 2024"

[bluGill]

A fab is $5billion. I know of a large company (I'm not allowed to say who, but you might be able to guess) that when faced with some 16bit CPU going out of production considered building a fab - manufacturing is the core competency, so why shouldn't they make our own chips, and thus keep those old designs based in obsolete CPUs that still work just find running for longer. The cost of a fab was high enough they decided not to. Of course on hindsight if they had built a fab it would have opened just as the supply chain problems started, and the company would have made a mint.

I don't think GM will open a fab on their own. Too expensive for what they need. However a joint GM/Ford/Toyota venture seems possible (if it can get past anti-trust laws!), and that would find customers in the likes of Honda.