> If the platform really needs to watch every cycle that tightly, you aren't going to be a general purpose platform, and you might as well just make a monolithic C++ embedded application, rather than a whole new platform that is very likely to have a low shelf life as the hardware platform evolves.
Which I think is agreeable, up to a certain point, because I think it's potentially naive. That monolithic C++ embedded application is going to be fundamentally built out of a scheduler, IO and driver interfaces, and a shell. That's the only sane way to do something like this. And that's an operating system.