What is virtualbox usb filter drivers#

In particular, UFX handles the process of enumerating the device and processing standard control transfers. UFX is responsible for implementing USB function logic that is common to all USB function controllers and handling and/or dispatching requests from USB function class drivers. USB is a standard bus and has some required functionality and capabilities. The USB function class extension (UFX) is a system-supplied extension to Kernel-Mode Driver Framework (KMDF). The class driver may be implemented purely as a kernel-mode driver, or it may be a user-mode service paired with the system-supplied class driver GenericUSBFn.sys.Ī function class driver sends requests to the controller by using USB function class driver to UFX programming interfaces. MTP and IpOverUsb are examples of system-supplied class drivers. For more information about these IOCTLs see Communicating with GenericUSBFn.sys from a user-mode serviceĪ USB function class driver implements the functionality of a specific interface (or group of interfaces) on the USB device. You can create a user-mode service that communicates with GenericUSBFn.sys by sending I/O control codes (IOCTLs) as defined in genericusbfnioctl.h.

All user-mode requests are sent to the Microsoft-provided kernel-mode class driver GenericUSBFn.sys.

The USB function stack is conceptualized in this image: The USB function stack creates PDOs for each interface and PnP Manager loads the class driver that creates the function device object (FDO) for that interface. A composite USB device can support multiple interfaces in a single configuration.

For example, the Media Transfer Protocol (MTP) for transferring files to and from the device. In a single configuration device, a USB device can define one or more interfaces.

What is virtualbox usb filter drivers#

On a USB device, the USB function stack refers to a group of drivers that are enumerated by the Plug and Play Manager, when ACPI creates a USB device physical device object (PDO). Describes the architecture of the USB function stack.