Writing Windows WDM Device Drivers
A nuts-and-bolts reference highlighting the Windows Driver Model (WDM).
TABLE OF CONTENTS Writing Windows WDM Device Drivers
Chapter 3: Device Driver Design
Introduction
This chapter introduces the basic concepts and structures that you will need to write drivers. Some ideas are sufficiently important and deserve to be mentioned now. All the other techniques, routines, and objects are covered in the following chapters.
Windows uses a layered design for passing requests from the end user to a driver stack and eventually to the hardware. As a trusted part of the operating system, a driver must be written well to fit into the kernel. It should use the kernel's abstract model of the processor and use memory carefully. Wherever possible, a driver should use the recommended techniques, routines, and structures.
Driver Design Guide
A good device driver needs to be well written. Remember that it is a trusted part of the operating system. The PC will not get the protection that a normal Win32 application has. If anything goes wrong, it is likely that the system will crash, or worse destroy valuable data before crashing.
For important projects, my ultimate design philosophy is to design code three times. At the outset, it is definitely worth while knowing where I am going and what features I am going to implement. I then prefer an incremental approach, in which each individual section of code is designed as I go along. However, as with many programs, it often only when I have finished a first-cut prototype of the whole driver that I really understand what is going on. Doing some real hardware interactions might invalidate some of my...
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