4.4BSD Internals Seminar

This seminar was part of the Computer Science House Operating System Seminar Series. The OS Seminar series is a weekly two hour seminar covering the internals of many modern operating systems. For more information, visit the link above.


The BSD operating system has been around in one form or another since 1977. Originally, it was derived from AT&T Unix, but recent releases have been "unencumbered". Since the dissolution of the CSRG, there are many groups supporting the BSD product: BSDI (commercial), NetBSD, FreeBSD, and OpenBSD. This seminar will focus on the CSRG's release of the 4.4BSD Operating System since it is a subset of all current BSD derivatives.

Beginning with a brief history of the development of BSD Unix, the seminar will quickly move into technical details. I'll start by describing briefly the tasks the kernel is responsible for, then I'll explain the interaction between the top and bottom halves. Following that, I'll describe processes, scheduling and context switching. Next I'll cover the implementation of virtual memory. If time allows, I'll cover the vnode layer and the basics of filesystems and device drivers.

Tad Hunt