Chris Cant - Writing Windows WDM Device Drivers

The Manufacturer section has a list of manufacturers (i.e., a list of manufacturer names and their section names). Table 11.2 has two manufacturers, Abc Inc and Xyz Ltd. Each manufacturer has a section that lists the product models that this INF file describes. Each product model defines various IDs and an installation section base name.

The Models section for Abc, Inc. is called Abc.Inc. This section has entries for each product that it sells. The entry for Product1 specifies that the Product1.Install section contains the main installation instructions. In this case, an optional Product1.Install.Services section has also been included. More optional install sections can be included.

The Product1.Install section has entries that point to yet more sections. The Product1.CopyFiles section lists the files to copy. The Product1.AddReg section lists the entries that must be made in the registry. Further sections at this level can be added for other installation options.

The Product1.Install.Services section is only used in Windows 2000 to specify a service entry.

Table 11.2 INF file section hierarchy

[Version]

[Strings]

[SourceDisksNames]

[SourceDisksFiles]

[DestinationDirs]

[Manufacturer]

Abc, Inc.=Abc.Inc

Xyz Ltd=Xyz.Ltd

[Abc.Inc]

Product 1=Product1.Install.HardwareId

Product 2=Product2.Install.HardwareId

[Product1.Install]

CopyFiles=Product1.CopyFiles

AddReg=Product1.AddReg

[Product1.CopyFiles]

…

[Product1.AddReg]

…

[Product1.Install.Services]

AddService=Product1,0x00000002,Product1.Service

[Product1.Service]

…

[Product2.Install]

…

…

[Xyz.Ltd]

…

The quickest way to explain how an INF file works is to use a real example. Listing 11.1 shows the INF file for the Wdm1 driver, Wdm1free.Inf.

It kicks off with a Version section, which says that all the drivers and devices installed by this INF file belong to the Unknown device class. The Provider entry is set to %WDMBook%. The Strings section at the end replaces %WDMBook% with its full name, WDM Book.

The SourceDisksNames section lists the installation disks. The first and only disk is labelled "Wdm1 build directory." The SourceDisksFiles section covers W98 and specifies that the only driver file, Wdm1.sys, is found on installation disk 1 and is found in subdirectory obj\i386\free. These options make it easy to install the Wdm1 driver directly from its development location. For a commercial release, it is simpler to put the driver files in the root directory. The SourceDisksFiles.x86 section covers W2000 and specifies that Wdm1.sys is found in the objfre\i386 subdirectory.

The Manufacturer section lists just one manufacturer, again called WDM Book. There is just one product model defined here in the WDM.Book section. The Wdm1 model name %Wdm1% is the one that is shown to the user, "WDM Book: Wdm1 Example, free build". The %Wdm1% model has a Hardware ID of *wdmBook\Wdml. Hardware IDs are covered later.

The Wdm1.Install section has the instructions for installing the Wdm1 driver in Windows 98. The files to copy are listed in the Wdm1.Files.Driver section and the registry entries are listed in the Wdm1.AddReg section.

Legacy non-Plug and Play devices may also have LogConfig sections to specify the resources that a device needs. See Chapter 15 for an example of this.

The Wdm1.Files.Driver section simply lists the files that must be installed. The DestinationDirs section specifies where the files listed in the Wdm1.Files.Driver section should go.

The Wdm1.AddReg section specifies that two registry entries should be created for the driver, DevLoader with *ntkern and NTMPDriver with Wdm1.sys. These entries are described in detail later.

That wraps it up for a Windows 98 installation. I shall look at the remaining Windows 2000 sections later.

Listing 11.1 Wdm1free.inf

; Wdm1free.Inf – install information file

; Copyright © 1998,1999 Chris Cant, PHD Computer Consultants Ltd

[Version]

Signature="$Chicago$"

Class=Unknown

Provider=%WDMBook%

DriverVer=04/26/1999,1.0.6.0

[Manufacturer]

%WDMBook% = WDM.Book

[WDM.Book]

%Wdm1%=Wdm1.Install, *wdmBook\Wdm1

[DestinationDirs]

Wdm1.Files.Driver=10,System32\Drivers

Wdm1.Files.Driver.NTx86=10,System32\Drivers

[SourceDisksNames]

1="Wdml build directory",,,

[SourceDisksFiles]

Wdm1.sys=1,obj\i386\free

[SourceDisksFiles.x86]

Wdm1.sys=1,objfre\i386

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; Windows 98

[Wdm1.Install]

CopyFiles=Wdm1.Files.Driver

AddReg=Wdm1.AddReg

[Wdm1.AddReg]

HKR,,DevLoader,,*ntkern

HKR,,NTMPDriver,,Wdm1.sys

[Wdm1.Files.Driver]

Wdm1.sys

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; Windows 2000

[Wdm1.Install.NTx86]

CopyFiles=Wdm1.Files.Driver.NTx86

[Wdm1.Files.Driver.NTx86]

Wdm1.sys,,,%COPYFLG_NOSKIP%

[Wdm1.Install.NTx86.Services]

AddService = Wdm1, %SPSVCINST_ASSOCSERVICE%, Wdm1.Service

[Wdm1.Service]

DisplayName = %Wdm1.ServiceName%

ServiceType = %SERVICE_KERNEL_DRIVER%

StartType = %SERVICE_DEMAND_START%

ErrorControl = %SERVICE_ERROR_NORMAL%

ServiceBinary = %10%\System32\Drivers\Wdm1.sys

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; Strings

[Strings]

WDMBook="WDM Book"

Wdm1="WDM Book: Wdm1 Example, free build"

Wdm1.ServiceName="WDM Book Wdm1 Driver"

SPSVCINST_ASSOCSERVICE=0x00000002 ; Driver service is associated with device being installed

COPYFLG_NOSKIP=2 ; Do not allow user to skip file

SERVICE_KERNEL_DRIVER=1

SERVICE_AUTO_START=2

SERVICE_DEMAND_START=3

SERVICE_ERROR_NORMAL=1

DestinationDirs Section

Each line in the DestinationDirs section specifies the base directory for files listed in a CopyFiles section.

The W2000 DDK lists the directory codes. For Windows 2000, code 12 means System32\ drivers in the Windows directory, but in Windows 98, it means System32\ioSubsys. However, WDM drivers must be installed in the Windows System32\drivers directory in both versions of Windows. Therefore, code 10 (for the Windows directory) must be used, with System32\Drivers specified as a subdirectory.

The Wdm1.Files.Driver entry is therefore set to 10,System32\Drivers, where 10 is code for the Windows directory (e.g., C:\Windows or C:\WINNT). The second field is the subdirectory to add to this base directory. Therefore, the Wdm1 driver files are stored in the Windows System32\Drivers directory.

AddReg Section