Well, the answer lives in books: Modern Operating Systems – Andrew S. Tanenbaum is a very good one. The cover illustration below. The simplest yet complete operating system kernel, suitable for learning or just curiosity, is Minix. Here you can browse the source code. (source: cs.vu.nl)
We used Andrew Tannenbaum’s Modern Operating Systems at the university I attended. I highly recommend it for it’s clear explanations of the tradeoffs inherent in many of the design decisions that you’ll run up against. This book is a little bit more “fair and balanced” than the Minix book. I also recommend this book because, … Read more
First things first. Read, read, read, read, read. You need to have a firm understanding of how the OS works before you can hope to implement your own. Grab one of Andrew Tanenbaum’s books on operating systems. This is the one we used in my OS class in college: Modern Operating Systems PDF Modern Operating … Read more
Answer recommended by Intel
There are a lot of links after this brief overview of what is involved in writing an OS for the X86 platform. The link that appears to be most promising (www.nondot.org/sabre/os/articles) is no longer available, so you’ll need to poke through the Archive.org version to read it. At the end of the day the bootloader … Read more