In most situations, developing a full file system driver is not necessary. First consider developing a
file system filter driver or a
file system minifilter driver.
This section includes the following topics.
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Using Extra Create Parameters with an IRP_MJ_CREATE Operation
Creating an INF File for a File System Driver
The Windows Setup and Device Installer Services, known collectively as
SetupAPI, provide the functions that control Windows setup and driver installation. The installation process is controlled by INF files.A file system driver's INF file provides instructions that SetupAPI uses to install the driver. The INF file is a text file that specifies the files that must be present for your driver to run and the source and destination directories for the driver files.
An INF file also contains driver configuration information that SetupAPI stores in the registry, such as the driver's start type and load order group.For more information about INF files and how they are created, see
Creating an INF File and
INF File Sections and Directives. For general information about signing drivers, see
Driver Signing.You can create a single INF file to install your driver on multiple versions of the Windows operating system. For more information about creating such an INF file, see
Creating INF Files for Multiple Platforms and Operating Systems and
Creating International INF Files.Starting with 64-bit versions of Windows Vista, all kernel-mode components, including non-PnP (Plug and Play) drivers such as file system drivers (file system, legacy filter, and minifilter drivers), must be signed in order to load and execute. For these
versions of the Windows operating system, the following list contains information that is relevant to file system drivers.-
INF files for non-PnP drivers, including file system drivers, are not required to contain [Manufacturer] or [Models] sections.
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The
SignTool command-line tool, located in the \bin\SelfSign directory of the WDK installation directory, can be used to directly "embed sign" a driver SYS executable file. For performance reasons, boot-start drivers must contain
an embedded signature. -
Given an INF file, the
Inf2Cat command-line tool can be used to create a catalog (.cat) file for a driver package. Only catalog files can receive
WHQL logo signatures. -
With Administrator privileges, an unsigned driver can still be installed on x64-based systems starting with Windows Vista. However, the driver will fail to load (and thus execute) because it is unsigned.
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For detailed information about the driving signing process, including the driving signing process for 64-bit versions of Windows Vista, see
Kernel-Mode Code Signing Walkthrough. -
All kernel-mode components, including custom kernel-mode development tools, must be signed. For more information, see
Signing Drivers during Development and Test (Windows Vista and Later).
INF files cannot be used to read information from the registry or to launch a user-mode application.
After creating an INF file, you will typically write the source code for your setup application. The setup application calls user-mode setup functions to access the information in the INF file and perform installation operations.
To construct your own file system driver INF file, use the following information as a guide. You can use the
ChkINF tool to check the syntax of your INF file.An INF file for a file system driver generally contains the following sections.
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Version (required)
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DestinationDirs (optional but recommended)
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SourceDisksNames (required)
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SourceDisksFiles (required)
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DefaultInstall (required)
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DefaultInstall.Services (required)
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ServiceInstall (required)
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DefaultUninstall (optional)
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DefaultUninstall.Services (optional)
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Strings (required)
Version Section (required)
The
Version section specifies the driver version information, as shown in the following code example.[Version] Signature = "$WINDOWS NT$" Provider = %Msft% DriverVer = 08/28/2000,1.0.0.1 CatalogFile =
The following table shows the values that file system filter drivers should specify in the
Version section.Entry Value Signature
"$WINDOWS NT$"
Provider
In your own INF file, you should specify a provider other than Microsoft.
DriverVer
CatalogFile
Leave this entry blank. In the future, it will contain the name of a WHQL-supplied catalog file for signed drivers.
DestinationDirs Section (optional but recommended)
The
DestinationDirs section specifies the directories where the file system driver files will be copied.In this section and in the ServiceInstall section, you can specify well-known system directories by using system-defined numeric values. For a list of these values, see
INF DestinationDirs Section. In the following code example, the value "12" refers to the Drivers directory (%windir%\system32\drivers).[DestinationDirs] DefaultDestDir = 12 ExampleFileSystem.DriverFiles = 12
SourceDisksNames Section (required)
The
SourceDisksNames section specifies the distribution media to be used.In the following code example, the
SourceDisksNames section lists a single distribution media for the file system driver. The unique identifier for the media is 1. The name of the media is specified by the %Disk1% token, which is defined in the
Strings section of the INF file.[SourceDisksNames] 1 = %Disk1%
SourceDisksFiles Section (required)
The
SourceDisksFiles section specifies the location and names of the files to be copied.In the following code example, the
SourceDisksFiles section lists the file to be copied for the file system driver and specifies that the files can be found on the media whose unique identifier is 1 (This identifier is defined in the
SourceDisksNames section of the INF file.)[SourceDisksFiles] examplefilesystem.sys = 1
DefaultInstall Section (required)
In the
DefaultInstall section, a
CopyFiles directive copies the file system driver's driver files to the destination that is specified in the
DestinationDirs section.Note The
CopyFiles directive should not refer to the catalog file or the INF file itself; SetupAPI copies these files automatically.You can create a single INF file to install your driver on multiple versions of the Windows operating system. This type of INF file is created by creating additional
DefaultInstall,
DefaultInstall.Services,
DefaultUninstall, and DefaultUninstall.Services sections for each operating system version. Each section is labeled with a
decoration (for example, .ntx86, .ntia64, or .nt) that specifies the operating system version to which it applies. For more information about creating this type of INF file, see
Creating INF Files for Multiple Platforms and Operating Systems.In the following code example, the
CopyFiles directive copies the files that are listed in the ExampleFileSystem.DriverFiles section of the INF file.[DefaultInstall] OptionDesc = %ServiceDesc% CopyFiles = ExampleFileSystem.DriverFiles [ExampleFileSystem.DriverFiles] examplefilesystem.sys
DefaultInstall.Services Section (required)
The
DefaultInstall.Services section contains an
AddService directive that controls how and when the services of a particular driver are loaded.In the following code example, the
AddService directive adds the file system service to the operating system. The %ServiceName% token contains the service name string, which is defined in the
Strings section of the INF file. ExampleFileSystem.Service is the name of the file system driver's
ServiceInstall section.[DefaultInstall.Services] AddService = %ServiceName%,,ExampleFileSystem.Service
ServiceInstall Section (required)
The ServiceInstall section adds subkeys or value names to the registry and sets values. The name of the
ServiceInstall section must appear in an
AddService directive in the
DefaultInstall.Services section.The following code example shows the ServiceInstall section for the file system driver.
[ExampleFileSystem.Service] DisplayName = %ServiceName% Description = %ServiceDesc% ServiceBinary = %12%\examplefilesystem.sys ServiceType = 2 ; SERVICE_FILE_SYSTEM_DRIVER StartType = 1 ; SERVICE_SYSTEM_START ErrorControl = 1 ; SERVICE_ERROR_NORMAL LoadOrderGroup = "File System" AddReg = ExampleFileSystem.AddRegistry
The DisplayName entry specifies the name for the service. In the preceding example, the service name string is specified by the %ServiceName% token, which is defined in the
Strings section of the INF file.The Description entry specifies a string that describes the service. In the preceding example, this string is specified by the %ServiceDesc% token, which is defined in the
Strings section of the INF file.The ServiceBinary entry specifies the path to the executable file for the service. In the preceding example, the value 12 refers to the Drivers directory (%windir%\system32\drivers).
The ServiceType entry specifies the type of service. The following table lists the possible values for
ServiceType and their corresponding service types.Value Description 0x00000001
SERVICE_KERNEL_DRIVER (Device driver service)
0x00000002
SERVICE_FILE_SYSTEM_DRIVER (File system or file system filter driver service)
0x00000010
SERVICE_WIN32_OWN_PROCESS (Microsoft Win32 service that runs in its own process)
0x00000020
SERVICE_WIN32_SHARE_PROCESS (Win32 service that shares a process)
The ServiceType entry should always be set to SERVICE_FILE_SYSTEM_DRIVER for a file system driver.
The StartType entry specifies when to start the service. The following table lists the possible values for
StartType and their corresponding start types.Value Description 0x00000000
SERVICE_BOOT_START
0x00000001
SERVICE_SYSTEM_START
0x00000002
SERVICE_AUTO_START
0x00000003
SERVICE_DEMAND_START
0x00000004
SERVICE_DISABLED
For detailed descriptions of these start types to determine which one is appropriate for your file system driver, see
What Determines When a Driver Is Loaded.Starting with x64-based Windows Vista systems, the binary image file of a boot-start driver (a driver that has a start type of SERVICE_BOOT_START) must contain an embedded signature. This requirement ensures optimal system boot performance. For more information,
see Kernel-Mode Code Signing Walkthrough.For information about how the StartType and LoadOrderGroup entries determine when the driver is loaded, see
What Determines When a Driver Is Loaded.The ErrorControl entry specifies the action to be taken if the service fails to start during system startup. The following table lists the possible values for
ErrorControl and their corresponding error control values.Value Action 0x00000000
SERVICE_ERROR_IGNORE (Log the error and continue system startup.)
0x00000001
SERVICE_ERROR_NORMAL (Log the error, display a message to the user, and continue system startup.)
0x00000002
SERVICE_ERROR_SEVERE (Switch to the registry's LastKnownGood control set and continue system startup.)
0x00000003
SERVICE_ERROR_CRITICAL (If system startup is not using the registry's LastKnownGood control set, switch to LastKnownGood and try again. If startup still fails, run a bug-check routine. Only the drivers that are needed for the system to startup should specify
this value in their INF files.)The LoadOrderGroup entry must always be set to "File System" for a file system driver. This is different from what is specified for a file system filter driver or file system minifilter driver where the
LoadOrderGroup entry is set to one of the file system filter load order groups. For more information about the load order groups that are used for file system filter drivers and file system minifilter drivers, see
Load Order Groups for File System Filter Drivers and
Load Order Groups and Altitudes for Minifilter Drivers.The
AddReg directive refers to one or more INF writer-defined
AddRegistry sections that contain any information to be stored in the registry for the newly installed service.Note If the INF file will also be used for upgrading the driver after the initial install, the entries that are contained in the
AddRegistry section should specify the 0x00000002 (FLG_ADDREG_NOCLOBBER) flag. Specifying this flag preserves the registry entries in HKLM\CurrentControlSet\Services when subsequent files are installed. For example:[ExampleFileSystem.AddRegistry] HKR,Parameters,ExampleParameter,0x00010003,1
DefaultUninstall Section (optional)
The DefaultUninstall section is optional but recommended if your driver can be uninstalled. It contains
DelFiles and
DelReg directives to remove files and registry entries.In the following code example, the
DelFiles directive removes the files that are listed in the ExampleFileSystem.DriverFiles section of the INF file.[DefaultUninstall] DelFiles = ExampleFileSystem.DriverFiles DelReg = ExampleFileSystem.DelRegistry
The
DelReg directive refers to one or more INF writer-defined
DelRegistry sections that contain any information to be removed from the registry for the service that is being uninstalled.DefaultUninstall.Services Section (optional)
The DefaultUninstall.Services section is optional but recommended if your driver can be uninstalled. It contains
DelService directives to remove the file system driver's services.In the following code example, the
DelService directive removes the file system driver's service from the operating system.[DefaultUninstall.Services] DelService = %ServiceName%,0x200
Note The
DelService directive should always specify the 0x200 (SPSVCINST_STOPSERVICE) flag to stop the service before it is deleted.Note There are certain classes of file system products that cannot be completely uninstalled. In this situation, it is acceptable to just uninstall the components of the product that can be uninstalled and leave installed the
components of the product that cannot be uninstalled. An example of such a product is the Microsoft Single Instance Store (SIS) feature.Strings Section (required)
The
Strings section defines each %strkey% token that is used in the INF file.For example, the file system driver defines the following strings in its INF file.
[Strings] Msft = "Microsoft Corporation" ServiceDesc = "Example File System Driver" ServiceName = "ExampleFileSystem" ParameterPath = "SYSTEM\CurrentControlSet\Services\ExampleFileSystem\Parameters" Disk1 = "Example File System Driver CD"
You can create a single international INF file by creating additional locale-specific
Strings.LanguageID sections in the INF file. For more information about international INF files, see
Creating International INF Files. -