obiwac wrote:
I don't know much about UEFI, but, for me, the fun of making an os is doing everything myself.
The question is always how you define "everything". DOS relied heavily on the BIOS, so you could argue that it wasn't doing everything by itself either. Relying heavily on UEFI would indeed be the modern-day equivalent. Of course, UEFI does a lot more than the BIOS did, so you'd have to figure out what pieces of additional functionality you can still deliver (I think this is Brendan's point).
Of course, when someone talks about making "a DOS", I understand that they want to make something that can run existing DOS programs. In this case, you obviously have to make the same design decisions as DOS made back then and keep using the BIOS. Well, or I guess you could just implement the necessary BIOS interfaces yourself and basically just treat them as part of your syscall interface.