Eliminating the OS to maximise high-performance code?

Question

Suppose I want to run some computational experiments, probably some mathematical simulations, and I want to get the best performance out of the system. I don't want the OS using up a significant chunk of physical memory, and the endless list of system services competing for CPU access.

What is the best way to boot the computer into some sort of ultra-minimal environment, where I can run a compiled program that I wrote with C. I need access to physical memory and probably some rudimentary access to a hard drive (I'm okay with no file system, and just reading/writing things by their absolute addresses).

I tried writing my own bootloader and had mixed success. I think I was able to get into 64-bit mode (long mode), but I wasn't sure where to go from there, in terms of running more code and interacting with the full set of physical memory and the hdd.

It's probably a bit much to ask, but GP-GPU would probably be handy too.

Answer 1

Sounds like a fun project, but tbh I think that you'll be much better off with one of the many existing super-minimal Linux distros (google around for JEOS, Linxu from scratch and more) or - if your code is small enough - why not freedos with a 32 bits extender like HX.

At least by starting from al albeit very much stripped-down general computing platform you don't have to worry about trivial stuff like different underlying hardware, networking, basic display and command line interfaces. All the time you win by not having to program that stuff can be invested in refining the mathematical model itself.