Mac OS X Internals: A Systems Approach

When a computer system's power is turned on, or the system is reset, the process of its "coming up" is called bootstrapping, or simply booting.^[1] A modern Apple computer presents a capable and interesting firmware environment even before an operating system runs on it. In this chapter, we will explore this environment on a PowerPC-based Macintosh computer. We will also look at the sequence of events that happens during bootingup to the point where the Mac OS X kernel gains control. Finally, we will briefly discuss an equally interesting firmware environment (EFI) for x86-based Macintosh computers.

^[1] The term is an allusion to the expression "lifting oneself up by the bootstraps."