Well, even Chrome OS and Firefox OS don't have their own kernels; they run on top of Linux.

If you were to build a Python OS, you'd probably start by writing PID 1 in Python. It would be a Python init, starting services written in Python, running gettys written in Python, and you'd log into a shell written in Python.

Hmm... I can actually see myself writing an init system in Python... (hell, I did exactly that at my last company.... I'd have to rewrite it from scratch, but that's no big deal...)

Great, I think I've found a new rabbit hole.

I wonder how much tweaking supervisord[1] would need to be suitable as a init replacement/for running as PID 1?

Incidentally, I also came across [2] -- which I wasn't aware of.

[1] http://supervisord.org/

[2] https://www.python.org/dev/peps/pep-3143/ https://pypi.python.org/pypi/python-daemon

Message me if you start this!

https://github.com/justincormack/ljsyscall is just that, but for Lua.

FFI to the kernel on Linux, NetBSD Rump kernels and even bare on Xen.

Every OS ever had a bootloader of some sort as far as I'm aware, in some cases you had to toggle them in through the front panel but I don't know of any OS that did not have a bootstrapping stage prepended.

The bootloader normally hands over the OS once it starts however, it doesn't continue running and acting as an interface to the hardware.

There's the bootloader, there's the bios and there is the operating system. It's perfectly legal to do bios calls from a running operating system (though there will be a price to pay for sure). The bootloader is usually discarded after the boot. The bios doesn't 'run' in any way either until you call it, think of it as a library that you can call.