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 5: Device Interfaces
This chapter explains how to use device interfaces to make a driver available to the kernel and Win32 user-mode applications. The device interface code in the Wdm1 driver is described.
The example Wdm1Test user-mode program shows how to use the Win32 functions to find device interfaces. Wdm1Test then sends some basic I/O requests to the Wdm1 driver.
Devices
A driver implements one or more devices. Each device represents an instance of a piece of real or virtual hardware. User-mode programs and the kernel access a driver's device through a device object.
Once a WDM driver's DriverEntry routine has completed, the driver has usually not created any devices. Instead, it has provided the kernel with various callback routine pointers. The Plug and Play (PnP) Manager calls the driver AddDevice callback routine each time the driver should create a device. The PnP Manager makes further calls to configure the device using the PnP IRP, as described in Chapter 8.
This chapter considers only two Plug and Play messages: when a device is added using AddDevice, and when it is removed. The Remove Device message is a PnP IRP with a minor function code of IRP_MN_REMOVE_DEVICE.
Device Access
User mode programs access drivers using the Win32 CreateFile function, passing a string in the lpFileName parameter. This routine is normally used to access files on disk. However, it can also be used to access a variety of other devices, such as pipes,...
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