The meaning of driver

The law is also subject to change from time to time and legal statutes and regulations vary between states. It is possible that the law may not apply to you and may have changed from the time a post was made. All information available on our site is available on an "AS-IS" basis.

It is not a substitute for professional legal assistance. More Definitions for driver. See the full definition for driver in the English Language Learners Dictionary. Nglish: Translation of driver for Spanish Speakers. Britannica English: Translation of driver for Arabic Speakers. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Log in Sign Up. Save Word. Definition of driver. Examples of driver in a Sentence Who was the driver at the time of the accident? We told the taxi driver to take us to the library. He likes to sit at the front of the bus, near the driver. There's a problem with the printer's driver. First Known Use of driver 14th century, in the meaning defined above. This diagram illustrates a user-mode application communicating with a kernel-mode software driver.

Software drivers always run in kernel mode. The main reason for writing a software driver is to gain access to protected data that is available only in kernel mode. However device drivers do not always need access to kernel-mode data and resources.

So some device drivers run in user mode. For more information about processor modes, see User Mode and Kernel Mode. There is a category of driver we have not mentioned yet, the bus driver. To understand bus drivers, you need to understand device nodes and the device tree.

For information about device trees, device nodes, and bus drivers, see Device Nodes and Device Stacks. Our explanation so far over simplifies the definition of function driver. We said that the function driver for a device is the one driver in the stack that communicates directly with the device.

The function driver for a PCI device obtains addresses that are mapped to port and memory resources on the device. The function driver communicates directly with the device by writing to those addresses.

However in many cases, a device does not connect directly to the PCI bus. Instead the device connects to a host bus adapter that is connected to the PCI bus. The function driver for the toaster communicates indirectly with the toaster by sending a request to the function driver for the USB host controller. The function driver for the USB host controller then communicates directly with the USB host controller hardware, which communicates with the toaster.