OS X and iOS Kernel Programming

Summary

In this chapter we have:

• Given an overview of the Mac OS X and iOS operating systems. We have discussed their general background and origin, with a particular focus on the kernel, the major topic of this book.
• Looked at the XNU kernel, which is the kernel for both OS X and iOS.
• Discussed the layered architecture of the XNU kernel, which consists of three major components: the Mach, the BSD, and the I/O Kit. The Mach layer can be seen as the inner ring, closest to the hardware, which provides services to the rest of the kernel. Services provided by the Mach layer include hardware abstraction, virtual memory, and task scheduling.
• Discussed the operation of the Mach scheduler, and the difference between tasks and threads. A task can be ...