What are device drivers? They are software that control particular hardware and tell other software or the operating system how to communicate with it. In this article, we talk about them a bit more. Are you interested in the examples of device drivers? Or maybe you want to learn what the 10 different types of device drivers are? If you answered yes to any of these questions, then keep reading!
What Are Device Drivers?
A device driver is a computer program that controls a particular hardware device. It provides the user with an interface for the device and enables the operating system and other software to communicate with the hardware and initiate its functions.
How does a device driver work? It runs at a high privilege in the system and uses a communication subsystem (computer bus) to which the device is connected. It works as a kind of translator – it translates the information and commands from the OS to the piece of hardware. They are what enables printers, keyboards, or mice to operate and work with modern PCs. But, what about embedded systems? What is the role of device drivers in them?
Similarly to general-purpose computers, embedded systems also run on hardware that requires device drivers to function properly. We can distinguish two types of such hardware: microcontroller peripherals and external devices. However, due to limited space (both physical and in terms of digital memory), the drivers for embedded systems must be strongly optimized. Otherwise, they won’t fit into the available space, increase energy consumption significantly, or affect the whole system’s performance.
The 10 Types of Device Drivers
There are many ways in which device drivers can be categorized. For instance, the most natural distinction includes two separate types: generic and specific device drivers. In such a case, the former are a part of the OS and do not require any additional input from the user to work; the latter are made for individual devices and usually need to be installed manually.
However, this isn’t the only way in which you can classify device drivers. Let’s take a look at a slightly more detailed categorization which we present below.
- Generic device drivers – As mentioned before, these are pre-installed drivers for general purposes and many devices.
- Specific device drivers – Installed by the user, they are prepared for a particular device (or a particular class of devices: see point 8 on this list)
- Kernel device drivers – These are the most generic drivers possible loaded along with the OS. They access RAM to function, hence the minimal requirements for every operating system.
- User-mode device drivers – These drivers are loaded in user mode and may be saved on the computer. This means that they are not as heavy for the system. They include the drivers for your typical external devices.
- Character device drivers – These deal with data in a stream of characters, where each character is treated independently. Examples of character devices include keyboards, mice, serial ports, and terminals – devices that typically handle input or output one character at a time.
- Block device drivers – This type handles file system requests, employing the strategy(9E) routine to execute disk I/O operations. They can also offer a character driver interface, enabling direct device access (raw interface).
- Original equipment manufacturer (OEM) drivers – OEM drivers, or Original Equipment Manufacturer drivers, are specific device drivers developed by the original hardware manufacturer for seamless integration and optimal performance with their products. These drivers ensure compatibility and functionality between the hardware and the operating system. Therefore, like kernel drivers, they are among the generic ones.
- Class drivers – These drivers are more general. They work for a particular class of similar hardware rather than for all or only one type. Most commonly, they are used for USB-connected devices. What is an example of such a device driver? A driver for printers that enables you to use several different lines of printers from the same manufacturer.
- Open-source drivers – Yes, open-source drivers got their separate category! This is because drivers are usually provided by the hardware (or software) manufacturer. It’s worth noting that these drivers offer more privacy, as it’s easy to eliminate the tracking code (if it’s included in the first place) from them.
- Virtual device drivers – These drivers are used to emulate the hardware of the host device that is running on a virtual machine.
Examples of Device Drivers
What are the examples of device drivers? There are plenty of them, but as users, we don’t usually pay much attention to them since our efforts are often limited only to installing and updating the drivers. So instead of going through the examples of such programs, let’s see what devices require drivers to function.
- I/O devices (keyboards, mice, CD/DVD drives, printers, graphics cards, etc.)
- Communication interfaces in embedded systems (UART, SPI)
- Display devices (LCDs or LEDs)
- Wireless modules
- USB controllers
- Real-Time Clocks
- Biometric Sensors
- Audio Codecs
You know what device drivers are, what functions they serve, what are their 10 types and what kind of hardware requires them to function. Do you feel that you need a customized driver for your embedded device? Then you’re in the right place! Check our device driver development services, and let us help you construct your embedded system!
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