Книга: Writing Windows WDM Device Drivers

Registering as an Event Source

Registering as an Event Source

The final hurdle to overcome is registering your driver as an event source so that the event viewer knows where to find your message text resource. Two registry changes must be made.

First, the HKLMSystemCurrentControlSetServicesEventLogSystem key has an existing REG_MULTI_SZ value called Sources. Add the name of your driver's executable (without the extension) as a line in Sources.

In this same registry key, make a new subkey with this same driver name. In this subkey, add a REG_EXPAND_SZ value called EventMessageFile and set a REG_DWORD called TypesSupported with a value of 0x7. For Wdm3, set EventMessageFile to the following value.

%SystemRoot%System32IoLogMsg.dll;%SystemRoot%System32DriversWdm3.sys

The Wdm3 installation INF file supposedly has the correct information to make these registry changes when a Wdm3 device is installed. Listing 13.4 shows the amendments made to the standard installation file. The AddService directive's last field specifies the name of the section containing the error logging registry values. There are optional fields to specify the log type (System, Security, or Application) and a log name.

The Wdm3.Service.EventLog section specifies the values for the EventMessageFile and TypesSupported values. The EventMessageFile entry is on one long line.

However, I found that this did not work completely in Windows 2000 Beta 3. "Wdm3" was correctly added to the Sources value and the HKLMSystemCurrentControlSetServicesEventLogSystemWdm3 key was correctly made, but no values were placed in the key.

It is simplest just to add these registry entries by hand. You will have to use RegEdt32 to use the required registry types.

For NT 3.51 and NT 4 drivers, you cannot use an INF installation file. Instead, you will have to amend your installation program to set up the registry entries. The example installation code, install.cpp (on the book's CD-ROM) shows how to do this job.

Listing 13.4 Wdm3free.inf installation file event logging sections

[Wdm3.Install.NT.Services]
AddService =
 Wdm3, %SPSVCINST_ASSOCSERVICE%, Wdm3.Service, Wdm3.Service.EventLog
; …
[Wdm3.Service.EventLog]
HKR,,EventMessageFile,%FLG_ADDREG_TYPE_EXPAND_SZ%,
 "%%SystemRoot%%System32IoLogMsg.dll;
  %%SystemRoot%%System32driversWdm3.sys"
HKR,,TypesSupported,%FLG_ADDREG_TYPE_DW0RD%,7

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