Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.

  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint

Device Drivers

One of the primary functions of an operating system is to provide hardware abstraction between platform hardware and the programs that run on it. This hardware abstraction typically occurs in device drivers that are part of the operating system, making those components an integral part of the system. IOS is no different in that regard. IOS contains device drivers for a range of platform hardware devices, such as Flash cards and NVRAM, but most notable are its device drivers for network interfaces.

IOS network interface device drivers provide the primary intelligence for packet operations in and out of interfaces. Each driver consists of two main components: a control component and a data component. The control component is responsible for managing the state and status of the device (for example, shutting down an interface). The data component is responsible for all data flow operations through the device and contains logic that assists with the packet switching operations. IOS device drivers are very tightly coupled with the packet switching functions, as we discuss in Chapter 2.


  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free 10-Day Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint