Programming the Microsoft Windows Driver Model

Who Should Read This Book

I've aimed this book at experienced programmers who don't necessarily know anything about writing device drivers for Windows operating systems. This book is for you if you want to learn how to do that. To succeed at driver writing, you will need to understand the C programming language very well because WDM drivers are written in C. You'll also need to be exceptionally able to tolerate ambiguity and to reverse-engineer portions of the operating system because a good deal of trial and error in the face of incomplete or inaccurate information is required.

Writing a WDM driver is much like writing a kernel-mode driver for Windows NT 4.0. It's a bit easier because you don't have to detect and configure your own hardware. Ironically, it's simultaneously harder because correctly handling Plug and Play and power management is fiendishly difficult. If you've written kernel-mode drivers for Windows NT, you'll have no trouble at all reading this book. You'll also be glad to have some code samples that you can cut and paste to deal with the aforementioned fiendishly difficult areas.

Writing a WDM driver is completely unlike writing a virtual device driver (VxD) for Windows 3.0 and its successors, a UNIX driver, or a real-mode driver for MS-DOS. If your experience lies in those areas, expect to work hard learning this new technology. Nonetheless, I think programming WDM drivers is easier than programming those other drivers because you have more rules to follow, leading to fewer choices between confusing alternatives. Of course, you have to learn the rules before you can benefit from that fact.

If you already own a copy of the first edition of this book and are wondering whether you should buy this revised edition, here's a bit of information to help you decide. Windows XP and Windows Me made few changes in the way you develop drivers for Windows 2000 and Windows 98, respectively. The main reason we decided to revise this book is that so many changes had accumulated on my update/errata Web page. This edition does, of course, explain some of the new bells and whistles that Windows XP brings with it. It contains more explicit advice about writing robust, secure drivers. It also, frankly, explains some things much better than the first edition does.

Chapter 1 has some information that will be useful to development managers and others who need to plan hardware projects. It's very embarrassing to be brought up short near the end of a hardware development project by the realization that you need a driver. Sometimes you'll be able to find a generic driver that will handle your hardware. Often, however, such a driver won't exist and you'll need to write one yourself. I hope to convince you managers in the first chapter that writing drivers is pretty hard and deserves your attention earlier rather than later. When you're done reading that chapter, by the way, give the book to the person who's going to carry the oar. And buy lots more copies. (As I told one of my college friends, you can always use the extra copies as dining room chair extenders for a young family.)