OS X and iOS Kernel Programming

The XNU Kernel

The XNU kernel is large and complex, and a full architectural description is beyond the scope of this book (there are other books that fill this need), but we will, in the following sections, outline some of the major components that make up XNU and offer a brief description of their responsibilities and mode of operation. In most cases when programming for the kernel you will be writing extensions rather than modifying the core kernel itself (unless you happen to be an Apple Engineer or contributor to Darwin), but it is useful to have a basic understanding of the kernel as a whole, as it will give a better understanding of how a kernel extension fit within the bigger picture. Subsequent chapters will focus on some of the more ...