What you describe is probably necessary for getting _fast_ Linux compatibility. However, if you are willing to take the overhead of a few layers of indirection, you can probably sandbox the Linux land somewhere, and not have it impact the rest of your design much.

Most hardware access doesn't have to be particularly efficient. And, yes, for the few pieces of hardware that you do want to support efficiently (eg your storage devices or networking, whatever you want to concentrate on in your design) these you can handle natively.

Btw, I would suggest that most people these days should write their toy operating systems to run as a VM on a hypervisor like Xen or similar. The surface to the outside world is smaller that way.

It has a rump kernel architecture which makes reusing the drivers almost trivial compared to reusing linus drivers with a new kernel.

  > you're never going to get there off of recycling linux's device drivers because that forces you to design your new OS as a linux clone in which cade you definitely did not need to write an entire new kernel from scratch.

probably it would have to be very general in design, but something along the lines of driverkit or iokit might work?