Computers as Components, 3rd Edition

6.1 Introduction

Although simple applications can be programmed on a microprocessor by writing a single piece of code, many applications are sophisticated enough that writing one large program does not suffice. When multiple operations must be performed at widely varying times, a single program can easily become too complex and unwieldy. The result is spaghetti code that is too difficult to verify for either performance or functionality.

This chapter studies the two fundamental abstractions that allow us to build complex applications on microprocessors: the process and the operating system (OS). Together, these two abstractions let us switch the state of the processor between multiple tasks. The process cleanly defines the state of an executing ...