What is device initialization?

what exactly is the process of device initialization? In programming we initialize vari开发者_开发技巧ables by assigning them some initial value. but what is the need to initialize a device in the first place and what values to initialize it with?

Device initialization is doing whatever steps are required to bring a device into a working state. It has got little to do with variable initialization. The process is specific for every device, there are no magic values that would initialize any device that you come across.

Device initialisation is exactly what it sounds like, preparing a device for use.

For example, when booting a PC, you may need to initialise the keyboard device to make it ready to accept keystrokes from the user.

Operating systems will tend to perform this activity on all devices they detect, hard drives, CD-ROMS, keyboard, video devices and so on, to bring them to a useful state for later use.