The source code of the Berkeley Software Distribution (BSD) UNIX system is freely available. This document is a guide for those who wish to port this system to a new architecture. Porting will most likely involve writing device drivers for the new machine, and may even require rewriting the assembly language portion of the operating system if BSD UNIX has not yet been ported to the target CPU. This guide will discuss how to get started in the project, what files need to be modified, what drivers need to be written, and what steps should be followed when releasing the port for public use.
It is assumed that the reader (along with everyone else involved in the port) has a thorough understanding of C, a good knowledge of how to use UNIX, and has taken at least an undergraduate-level course in operating systems.