Is There a Sample Driver?

Yes, you may get it over here. The sample driver, which demonstrates presence of a bus filter by adding a new compatible ID, "BffDevice", to the compatible IDs list, must be installed on Windows 7 or higher, x86.

If you have an old CalDight T3/T4, you may also try the experimental driver, which will add "BffDevice" compatible ID to each of the disks inserted to T3/T4. Thereafter, you may run as administrator asm106x\create_raid_volume.ps1 in PowerShell to create a RAID 5 volume with those disks.

Caution: Make sure you have backed up data in your disks before you run asm106x\create_raid_volume.ps1.

May I Make a Feature Request?

Yes, please fill this form. Please note that not every feature request will be accepted.

How Do I Get the WDM Device Object of a Bus Filter?

BFF provides the following routine for this purpose:

PDEVICE_OBJECT BffDeviceWdmGetDeviceObject(WDFOBJECT BffDevice);

where BffDevice is the WDF general object handle to the bus filter device object.

BffDeviceWdmGetPhysicalDevice

Description

Retrieve the PDO from the device stack of the specified WDF object.

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Declaration

PDEVICE_OBJECT BffDeviceWdmGetPhysicalDevice(WDFOBJECT BffDevice);

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Parameter

BffDevice

The WDF object as a bus filter device object.

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Return value

The PDO for success; NULL otherwise.

BffDeviceWdmGetAttachedDevice

Description

Retrieve the next lower WDM device object in the device stack of the specified WDF object.

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Declaration

PDEVICE_OBJECT BffDeviceWdmGetAttachedDevice(WDFOBJECT BffDevice);

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Parameter

BffDevice

The WDF object as a bus filter device object.

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Return value

The next lower WDM device object for success; NULL otherwise.

BffDeviceWdmGetDeviceObject

Description

Retrieve the WDM bus filter device object that is associated with the specified WDF object.

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Declaration

PDEVICE_OBJECT BffDeviceWdmGetDeviceObject(WDFOBJECT BffDevice);

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Parameter

BffDevice

The WDF object as a bus filter device object.

Return value

The WDM bus filter device object for success; NULL otherwise.

BffPreprocessQueryBusRelations

Description

The callback function for an upper filter driver to preprocess IRP_MN_QUERY_DEVICE_RELATIONS/BusRelations before KMDF. This routine can be passed as EvtDeviceWdmIrpPreprocess into WdfDeviceInitAssignWdmIrpPreprocessCallback for IRP_MJ_PNP/IRP_MN_QUERY_DEVICE_RELATIONS, or be invoked in an upper filter driver's EvtDeviceWdmIrpPreprocess callback function. In the latter case, the upper filter driver must return the value that this routine returns.

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Declaration

NTSTATUS BffPreprocessQueryBusRelations(WDFDEVICE Device, PIRP Irp);

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Parameters

Device	The WDF device object representing an upper filter device object.
Irp	The IRP_MN_QUERY_DEVICE_RELATIONS I/O request packet.

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Return value

The value that WdfDeviceWdmDispatchPreprocessedIrp returns.