'Major Issues in Virtualizing a SERIALPORT'

摘要

Welcome to the World of device drivers. Actually the device driver deliberatelyrngeneric. So, how do drivers work? Each hardware device communicates with your PC using arnunique language that only its driver knows. When you print a document, for example, yourrncomputer issues a set of generic commands to the printer driver, and the driver translatesrnthose commands into the specialized instructions your printer understands. In order to viewrnthe drivers loaded on your computer in Windows 95/98, right-click the My Computer icon onrnthe desktop and select Properties. Click the Device Manager tab. This paper tries to give somernvital points in the serial driver for legacy COM ports. This is a general introduction to thernresources and development environment needed to write drivers. Of course the development itrnhas a close relation with the Microsoft offers the Driver development kit (DDK) all itsrnoperating system which incorporates the Windows Driver Model (WDM).rnFrankly speaking, for a new developer should have an idea of the driver developmentrnarchitecture of the Intel x86 family of microprocessor in order to understand thernfollowing general concepts.rn1. Protected and virtual 8086 mode operationrn2. Flat memory modelrn3. Interrupt and privilege processing Segment and page memory management and faultrnhandlingrnThe Microsoft WDM has facilitated with many way for the driver developmentrnfor its entire platform. But third party S/W Vendor's offering DDK for every need.rnThis makes the driver development more comfortable.rnHere "Driver works" designed to provide a simple entry into Windows NTrndevice driver programming than the Microsoft DDK offers. The Driver driver'srnlibraries reduce driver code size considerably without any performance penalty. Ofrncourse, the entire C-level API of the DDK is available.