HOWTO: Create Device Objects in Dispatch Routines

ID: Q126368

The information in this article applies to:

Microsoft Win32 Device Driver Kit (DDK) for Windows NT, versions 3.5, 3.51

SUMMARY

Most Windows NT kernel-mode device drivers create their device objects in either the DriverEntry routine or in a routine called by the DriverEntry routine. However, it is possible to create device objects in Dispatch routines.

After the device object has been created (IoCreateDevice) and the initialization is complete, the flag DO_DEVICE_INITIALIZING must be cleared before the device object can be used. If this flag is not cleared, CreateFile requests for this device object will fail (that is, applications will not be able to open the device).

Clear the flag as follows:


   deviceObject->Flags &= ~DO_DEVICE_INITIALIZING;


Keywords          : NTDDKKMode 
Version           : WINNT:3.5,3.51;
Platform          : winnt 
Issue type        : kbhowto

Last Reviewed: March 2, 1999