As someone who has written no-os code, you do not need to do everything the OS does. If you do not mind giving up most of your RAM, you can stick to realmode an

As someone who has written no-os code, you do not need to do everything the OS does. If you do not mind giving up most of your RAM, you can stick to realmode and take advantage of the BIOS functions (you can work around the RAM limitation by jumping between modes). If your computer has UEFI, you have access to a much more advanced set of functions, and (for many purposes) can target that. I haven't done anything beyond hello world type stuff on UEFI, but it feels like you can get alot done without noticing the lack of an OS.