Generic virtual device driver

摘要

A method and apparatus provides for handling communications between an application and a device through a device driver. Calls or commands are used by the device driver to access the hardware that are common to a number of different types of devices that are to be handled by the device driver. These calls or commands are used to store or save away information in the device when an application accessing the device shifts into a background state from a foreground state. These commands are used to restore information to the device when the application shifts back into the foreground state from the background state. In addition, a range of I/O ports used to access the devices are identified and predicted. For example, with video adapters, port address ranges are trapped for addresses identified through both PCI and VESA BIOSES.