System for modifying functions of static device driver using a registered driver extension extended dynamically by providing an entry point for the driver extension

摘要

A method of changing the functionality of a statically bound device driver, by dynamically extending the static device driver using a registered driver extension. The static device driver has a plurality of handlers or functions (such as input/output functions) used to control a device that is connected to or part of the computer system, and the driver extension modifies at least one of these functions, although it can be used to change several, or even all, of the functions. In the embodiment wherein the computer system is a UNIX-type workstation having a kernel residing in the memory, the static device driver is loaded in the kernel and is dynamically extended by providing at least one entry point for the driver extension.