Using Python to investigate EFI and ACPI

"Very simple cases" is all I had in mind. Hardware has become so cheap that dealing with the complexity and unpredictability of a scheduler and preemption is not always worth it. See Arduino as a good and successful example.

For reacting to different events something like select()/poll() / or any kind of non-blocking event loop does the job. Even Java can do stuff like this (not for real-time but for scalability)

This reminds me of this (also successful) product I used to work on. It permanently hogs/hogged (some) CPU cores thanks to Linux' SCHED_FIFO and implements its own event loop with incredibly good real-time properties. This worked surprisingly well considering the kernel was not designed for this and caused almost no problem. I found only this one at the time: https://bugzilla.kernel.org/show_bug.cgi?id=16011

More worrying from a "bare-metal" perspective is Josh's comment about background tasks in EFI, I did not expect that.