"Kobus Engelbrecht" <kobus.engelbrecht@kentron.co.za> wrote:
It is important to understand, however, that NO ONE in real life actually
registers their ioctl codes with Microsoft. Unless you are the PCI SIG or
the USB controlling organization or the 1394 owners, this is not an issue.

IRP_MJ_INTERNAL_DEVICE_CONTROL is used strictly for driver-to-driver
communication. Application-to-driver calls ALWAYS come in as
IRP_MJ_DEVICE_CONTROL.

For example, display drivers and printer drivers do not support
DeviceIoControl.

If you are communicating from an application to your driver, your driver
will be seeing IRP_MJ_DEVICE_CONTROL, and you can define whatever ioctl
codes you need to (as long as they follow the ioctl rules in winioctl.h.)

What kind of a device are you creating? The more specific the question,
the more useful our answers.
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.