@wacco: and still, the thing you plan to have in ring0 will be your kernel, so the plan to have something "kernel-less" is a bit high fetched, to speak honestly. You need it, at least for dealing with interrupts and for the task switching as you already state.
By the way, you've issued a true word, pretty well applicable to most other situations too: let's make something functional ere we talk about it. I like this credo. Reminds me of my own philosophy.
stay safe.
) an exokernel still forces an interprocess communication protocol, where mine doesn't even care about that anymore. But if you'd like to call it an exokernel, fine by me. The idea remains the same: there isn't much left to do for the kernel, userprocesses deal with practically everything.