I'm surprised there aren't more hand-crafted OSs popping up on HN. Agentic AI can give you the basics of an OS in 15 minutes. It gets confused when debugging assembly code, but it can give you a good framework and walk you though the remainder of the steps.
The biggest problem on today's OS is I/O driver. Specifically USB driver.
I am intrigued. Go ahead and show us ONE 15 minute agentic ai os that runs on metal.
I threw myself at it for weeks and couldn't even get a blinking LED to run on the bare metal on a RPi.