Jump to navigation Jump to search This article is about device drivers for hardware. In computing, a device driver is a computer program that operates or controls a particular type of device that download driver canon lbp 810 windows 7 attached to a computer. A driver communicates with the device through the computer bus or communications subsystem to which the hardware connects.
When a calling program invokes a routine in the driver, the driver issues commands to the device. The main purpose of device drivers is to provide abstraction by acting as a translator between a hardware device and the applications or operating systems that use it. Programmers can write higher-level application code independently of whatever specific hardware the end-user is using. For example, a high-level application for interacting with a serial port may simply have two functions for “send data” and “receive data”. At a lower level, a device driver implementing these functions would communicate to the particular serial port controller installed on a user’s computer.
Writing a device driver requires an in-depth understanding of how the hardware and the software works for a given platform function. Because drivers require low-level access to hardware functions in order to operate, drivers typically operate in a highly privileged environment and can cause system operational issues if something goes wrong. The task of writing drivers thus usually falls to software engineers or computer engineers who work for hardware-development companies. This is because they have better information than most outsiders about the design of their hardware. The advantage of loadable device drivers is that they can be loaded only when necessary and then unloaded, thus saving kernel memory.
Kernel space can be accessed by user module only through the use of system calls. End user programs like the UNIX shell or other GUI-based applications are part of the user space. These applications interact with hardware through kernel supported functions. Because of the diversity of modern hardware and operating systems, drivers operate in many different environments.
So choosing and installing the correct device drivers for given hardware is often a key component of computer system configuration. Virtual device drivers represent a particular variant of device drivers. Virtual devices may also operate in a non-virtualized environment. For example, a virtual network adapter is used with a virtual private network, while a virtual disk device is used with iSCSI.