OS X and iOS Kernel Programming

C H A P T E R  1

Operating System Fundamentals

The role of an operating system is to provide an environment in which the user is able to run application software. The applications that users run rely on services provided by the operating system to perform tasks while they execute, in many cases without the user—or even the programmer—giving much thought to them. For an application to read a file from disk, for example, the programmer simply needs to call a function that the operating system provides. The operating system handles the specific steps required to perform that read. This frees the application programmer from having to worry about the differences between reading a file that resides on the computer's internal hard disk or a file on ...