Chapter 2Design Overview of 4.4BSD
2.1 4.4BSD Facilities and the Kernel
The 4.4BSD kernel provides four basic facilities: processes, a filesystem, communications, and system startup. This section outlines where each of these four basic services is described in this book.
1. Processes constitute a thread of control in an address space. Mechanisms for creating, terminating, and otherwise controlling processes are described in Chapter 4. The system multiplexes separate virtual-address spaces for each process; this memory management is discussed in Chapter 5.
2. The user interface to the filesystem and devices is similar; common aspects are discussed in Chapter 6. The filesystem is a set of named files, organized in a tree-structured hierarchy ...