The IOCTL_INTERNAL_I8042_HOOK_KEYBOARD request does the following:

  • Adds an initialization callback routine to the I8042prt keyboard initialization routine
  • Adds an ISR callback routine to the I8042prt keyboard ISR
The initialization and ISR callbacks are optional and are provided by an upper-level filter driver for a PS/2-style keyboard device.

After I8042prt receives an IOCTL_INTERNAL_KEYBOARD_CONNECT request, it sends a synchronous IOCTL_INTERNAL_I8042_HOOK_KEYBOARD request to the top of the keyboard device stack.

After Kbfiltr receives the hook keyboard request, Kbfiltr filters the request in the following way:

  • Saves the upper-level information passed to Kbfiltr, which includes the context of an upper-level device object, a pointer to an initialization callback, and a pointer to an ISR callback
  • Replaces the upper-level information with its own
  • Saves the context of I8042prt and pointers to callbacks that the Kbfiltr ISR callback can use
For more information about this request and the callbacks, see the following topics:

I8042prt Callback Routines

Kbfiltr Callback Routines

Major code


Input buffer

The Parameters.DeviceIoControl.Type3InputBuffer points to an INTERNAL_I8042_HOOK_KEYBOARD structure. This structure includes the following members:

Input buffer length

The Parameters.DeviceIoControl.InputBufferLength member is set to a value that is greater than or equal to the size, in bytes, of an INTERNAL_I8042_HOOK_KEYBOARD structure.

Output buffer


Output buffer length


Status block

The Status member is set to one of the following values:


Parameters.DeviceIoControl.InputBufferLength is less than the size, in bytes, of an INTERNAL_I8042_HOOK_KEYBOARD structure.


The request completed successfully.


Requirement Value
Header ntdd8042.h (include Ntdd8042.h)

See also