OS X and iOS Kernel Programming

Hardware and Drivers

In addition to managing essential hardware resources such as the CPU and memory, the operating system is also responsible for managing hardware peripherals that may be added to the system. This includes devices such as the keyboard and mouse, a USB flash drive, and the graphics card. Although the operating system is responsible for managing these devices, it does so with the help of drivers, which can be thought of as plug-ins that run inside the operating system kernel and allow the system to interface to hardware devices.

The code to support a hardware device can be found in two places: on the device itself (known as firmware) and on the computer (known as the driver). The role of the driver is to act on behalf of the operating ...