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Steve Zuel
Steve Zuel

Driver Keyboard Filter 01 Xp [2021]

This is an upper device filter driver sample for PS/2 keyboard. This driver layers in between the KbdClass driver and i8042prt driver and hooks the callback routine that moves keyboard inputs from the port driver to class driver. In its current state, it only hooks into the keyboard packet report chain, the keyboard initialization function, and the keyboard ISR, but does not do any processing of the data that it sees. (The hooking of the initialization function and ISR is only available in the i8042prt stack.) With additions to this current filter-only code base, the filter could conceivably add, remove, or modify input as needed.

driver keyboard filter 01 xp

This sample also creates a raw PDO and registers an interface so that applications can talk to the filter driver directly without going through the PS/2 devicestack. The reason for providing this additional interface is because the keyboard device is an exclusive secure device and it's not possible to open the device from usermode and send custom ioctls through it.

This driver filters input for a particular keyboard on the system. If you want to filter keyboard inputs from all the keyboards plugged into the system, you can install this driver as a class filter below the KbdClass filter driver by adding the service name of this filter driver before the KbdClass filter in the registry at:

This step is required for automatic deployment (described later) to work properly. In the kbfiltr.inx file (located with the driver source files), find the [DDK_Ex.Mfg.NT$ARCH$] section. Change the hardware ID in the %DDK_Ex% entry from the dummy value to the hardware ID of the PS/2 keyboard on the target computer. The following example shows the hardware ID change.

In File Explorer, navigate to the folder that contains your built driver package. The location of this folder varies depending on what you set for configuration and platform. For example, if your settings are Debug and x64, the package is your solution folder under \Debug\Package.

The computer where you install the driver is called the target computer or the test computer. Typically this is a separate computer from where you develop and build the driver package. The computer where you develop and build the driver is called the host computer.

Check Enable deployment, and check Remove previous driver versions before deployment. For Target Computer Name, select the name of a target computer that you provisioned previously. Select Install and Verify, and choose Default Driver Package Installation Task in the list. Click OK.

Before you manually deploy a driver, you must turn on test signing and install a certificate on the target computer. You also need to copy the DevCon tool to the target computer. For instructions, see Preparing a Computer for Manual Driver Deployment.

On the target computer, in a Command Prompt window, enter devmgmt to open Device Manager. In Device Manager, on the View menu, choose Devices by type. In the device tree, locate DDK Example Device that needs filtering under the Keyboards node.

To use the test application provided with the sample, it must be copied to the target computer manually. Save the kbftest.exe file from the folder where the build result is placed (for example, exe\Debug). This file is copied somewhere on the target, possibly where the driver package files are located. The test application is the executed on the target computer in a Command Prompt using kbftest as the command.

as notified Harry Johnston need use IoSetCompletionRoutineEx - but documentation for this is bad and not explain all details. absolute mandatory study windows src files (WRK-v1.2 for example) and binary windows code. if you look for implementation of IoSetCompletionRoutineEx - you can view that this routine nothing do for prevent you driver for unloading. it simply allocate small memory block, save here your DeviceObject, Context and CompletionRoutine and set IopUnloadSafeCompletion as completion and pointer to allocated memory block as context.

but this assume that Usc->DeviceObject IS VALID at calling IopUnloadSafeCompletion time. you can delete/de-reference DeviceObject inside CompletionRoutine , do some task which cause your driver unload - and will be no crash, because your CompletionRoutine protected by adding reference to your device. but if IopUnloadSafeCompletion will be called when your device already destroyed and driver unloaded - any way will be crash.

you can ask for what in this case IoSetCompletionRoutineEx at all, if we yourself call ObfReferenceObject / ObfDereferenceObject ? because if DriverUnload already called - all your code hold only on single reference on DeviceObject - so when you call ObfDereferenceObject(DeviceObject); from OnComplete - your device will be deleted and driver unloaded inside ObfDereferenceObject and finally this routine returned to your unloaded code. so sense of IoSetCompletionRoutineEx is protect your completion routine.

assume that while NtReadFile using pointer to your B device, another thread called your DriverUnload which delete B device and unload driver. handle/file object exist on device A - this hold it and prevent from unloading. but your attached B device not hold nothing. as result if NtReadFile or any another I/O subsystem routine which use your device execute in concurrent with DriverUnload where you call detach/delete device - system can crash already inside NtReadFile code. and you nothing can do with this. only one way after call IoDetachDevice some(how many ?!) time wait before call IoDeleteDevice. fortunately possibility of this case very low usual.

so try understand - system can crash in NtReadFile already. even if your Dispatch called - your DeviceObject can be deleted/not valid already or driver unloaded during dispatch routine. only after you call ObfReferenceObject(DeviceObject) all become ok. and all this problem because you try detach attached device in DriverUnload (windows not designed for this).

also can noted many another errors in your code. say completion routine must not return Irp->IoStatus.Status it must return or StopCompletion (i.e STATUS_MORE_PROCESSING_REQUIRED ) or any another value - usual ContinueCompletion (i.e STATUS_CONTINUE_COMPLETION or 0) also need not hardcode "\\Device\\KeyboardClass0" but use IoRegisterPlugPlayNotification with GUID_CLASS_KEYBOARD if you not wdm driver. also for xp need special handler for IRP_MJ_POWER ( Passing Power IRPs ) but may be this is already not actual if xp support not actual.

Note Only a driver that can guarantee it will not be unloaded before its completion routine finishes can use IoSetCompletionRoutine. Otherwise, the driver must use IoSetCompletionRoutineEx, which prevents the driver from unloading until its completion routine executes.

PS: the one-keystroke delay in the functionality taking effect is to be expected, because your driver isn't hooked into the read operation that was already in progress when it was loaded. I'm not sure whether there's any reasonable way to do that.

There may be hardware driver updates that are available or pending restart. Updating your Surface might fix issues you're experiencing. To check for updates, from Search, type Check for Updates, then select it as the Best match and then select Check for updates. For info on other ways to update your Surface, see Download drivers and firmware for Surface.

If your keyboard or touchpad is slow to respond, this is most likely because your Surface is having issues processing the applications and services on your device. Make sure your Surface has enough resources to perform typing or cursor functions.

Not all devices have a keyboard backlight feature. If your Surface Type Cover or Keyboard has this feature, there will be a button on the keyboard. As you press it, the backlight will increase and decrease in brightness, including off.

If you have installed a custom or clean Windows image and need to install Keyboard drivers, manually install the latest driver package for your version of Windows. Follow the steps at Download drivers and firmware for Surface.

For wireless keyboards, make sure that Bluetooth is enabled and you can connect to your device in the Settings menu. You can repair a connection by manually disconnecting and reconnecting your device.

When the Device Manager opens, scroll through and expand the Keyboard section. Right-click the keyboard you want to check and select Update driver to check for updates.

If your keyboard has additional keys or controls, custom drivers or software might be needed for the device to work correctly. For example, keyboards from companies like Logitech are supplied with specialized software. Manufacturer software like this will often come with a troubleshooting component to help you fix problems.

Having characters appear on the screen seconds after you press them on the keyboard can slow you down and reduce your productivity. Many factors make typing feel out of sync on Windows devices. A slow computer, faulty USB ports, outdated keyboard drivers, and misconfigured keyboard settings are a few of the reasons for keyboard lag.

Also, ensure the keyboard is near the dongle/receiver or your computer. This also applies to Bluetooth-powered keyboards. Using a wireless keyboard several yards away from your PC could lead to input delay.

Microsoft designed the Filter Keys functionality to make typing easier for users with neurological


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