What is a device driver primary function

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.

Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. What is a driver? Please rate your experience Yes No. Any additional feedback? Instead of enabling the guest operating system to dialog with hardware, virtual device drivers take the opposite role and emulates a piece of hardware, so that the guest operating system and its drivers running inside a virtual machine can have the illusion of accessing real hardware. Attempts by the guest operating system to access the hardware are routed to the virtual device driver in the host operating system as e.

The virtual device driver can also send simulated processor-level events like interrupts into the virtual machine. 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. A good example for virtual device drivers can be Daemon Tools. Solaris descriptions of commonly used device drivers:. The vendor ID identifies the vendor of the device.

A PCI device has often an ID pair for the main chip of the device, and also a subsystem ID pair which identifies the vendor, which may be different from the chip manufacturer. Template:Operating systems. Ultimate Pop Culture Wiki Explore. Wiki Content. Explore Wikis Community Central. Register Don't have an account? Device driver. Edit source History Talk 0. This article is about device drivers for hardware. For other software drivers, see Driver software.

Without drivers, the computer could not send and receive data correctly to hardware devices, such as a printer. Hardware devices that are unknown by the operating system or have features unknown by the operating system all require drivers. Below is a list of hardware devices and peripherals that require drivers.

Today's operating systems have many generic drivers that allow hardware to work at a basic level without needing drivers or software.

However, if that device has features unknown to the operating system, it will not work without drivers. For example, you could plug any keyboard into a computer and expect it to work.

However, if that keyboard has any special keys or features, they will not work until the drivers are installed. The operating systems' generic driver may not be updated as often as the drivers from a hardware manufacturer or computer manufacturer. If the appropriate driver is not installed, the device may not function properly, if at all. With some devices, the device may work, but all of its features may not work.

For example, a computer mouse usually works without drivers, but if it has more buttons than the traditional mouse, those extra buttons will not work until the drivers are installed.

For Microsoft Windows users, missing drivers may cause a driver conflict or an error in the Device Manager. By: Leah Zitter Contributor. Dictionary Dictionary Term of the Day. Decentralized Finance. Techopedia Terms. Connect with us. Sign up. Term of the Day. Best of Techopedia weekly. News and Special Offers occasional. Device Driver.