How does device driver work




















After the driver gets the data from the device, it returns the data to the operating system, which returns it to the application. In many cases, a device is designed according to a published hardware standard. This means that the driver can be written by Microsoft, and the device designer does not have to provide a driver.

The conventional way to visualize the stack is with the first participant at the top and the last participant at the bottom, as shown in this diagram.

Some of the drivers in the stack might participate by transforming the request from one format to another. These drivers do not communicate directly with the device; they just manipulate the request and pass the request along to drivers that are lower in the stack.

Function driver : The one driver in the stack that communicates directly with the device is called the function driver. Filter driver : The drivers that perform auxiliary processing are called filter drivers. For more information on stacks, see Driver stacks.

We could expand our definition of driver by saying that a driver is any software component that observes or participates in the communication between the operating system and a device. Our expanded definition is reasonably accurate but is still incomplete because some drivers are not associated with any hardware device at all.

For example, suppose you need to write a tool that has access to core operating system data structures, which can be accessed only by code running in kernel mode. You can do that by splitting the tool into two components.

The first component runs in user mode and presents the user interface. When we get a peripheral device such as printer, scanner, keyboard or modem, the device comes together with a driver CD which needs to be installed before the device starts working. As soon we install the driver software into the computer, it detects and identifies the peripheral device and we become able to control the device with the computer.

Keep reading for more on why drivers are important, including some more examples, as well as information on how to keep your drivers updated and what to do if they're not working properly.

Think of device drivers like translators between a program you're using and a device that that program wants to utilize somehow. The software and the hardware were created by different people or companies and speak two completely different languages, so a translator the driver allows them to communicate. In other words, a software program can provide information to a driver to explain what it wants a piece of hardware to do, information the device driver understands and then can fulfill with the hardware.

Thanks to device drivers, most software programs don't need to know how to work directly with hardware, and a driver doesn't need to include a full application experience for users to interact with.

Instead, the program and driver simply need to know how to interface with each other. This is a pretty good deal for everyone involved, considering that there is a nearly endless supply of software and hardware out there. If everyone had to know how to communicate with everyone else, the process of making software and hardware would be near impossible.

The drivers for each piece of hardware in your Windows computer are centrally managed from Device Manager , available in all versions of Microsoft Windows. Most of the time, drivers install automatically and never need more attention, aside from the occasional updating to fix bugs or add a cool new feature.

This is true for some drivers in Windows that are downloaded via Windows Update. When a manufacturer releases a driver update, it's your responsibility to install it. Some companies provide programs that will check for and install any relevant updates , but most don't make it that easy.

Fortunately, there are free driver updater programs that serve the same purpose, and work with all types of drivers. Some will even check for updates automatically and download and install them for you, much like Windows Update.

Here are some common tasks in Windows involving drivers:. Here are a few additional resources related to drivers:. Many problems that can be isolated to a particular piece of hardware aren't problems with the actual hardware itself, but issues with the device drivers that are installed for that hardware.

Some of the resources linked above should help you figure all that out. When a driver update is available from a hardware manufacturer, it will be available for free from their website.

When the driver is installed it creates what is called a "device object" which is designed to control the specific peripheral device it is connecting to.

The driver represents the peripheral device and consists of a physical structure of modes that make up the process of allowing your operating system to control the peripheral device. Drivers operate in what is known as the "kernel" mode which is a mode that can be handled by the Windows operating system. Drivers that operate in the kernel mode are able to interact with the Windows system memory and corresponding hardware.

This is different than user mode where programs can use the applications that are provided by the operating system but they cannot access the hardware directly.



0コメント

  • 1000 / 1000