IOCTL_VIDEO_MAP_VIDEO_MEMORY IOCTL

Maps the video hardware frame buffer and video RAM into the virtual address space of the requester. Miniport drivers are required to handle this IOCTL and to map all video memory in the caller's address space with VideoPortMapMemory.

This request is both modal and nonmodal: the miniport driver must return the location size of the frame buffer within video memory, and the frame buffer size and location can vary from mode to mode (modal characteristic). However, a subsequent set-mode operation (to the same mode) must not cause the video memory to change location (nonmodal characteristic).

Major Code

IRP_MJ_DEVICE_CONTROL

Input Buffer

The VRP InputBuffer contains a VIDEO_MEMORY structure specifying either a requested virtual base address or zero, which requests the system to assign a virtual base address mapped to the adapter's RAM and frame buffer range(s).

Input Buffer Length

Output Buffer

The miniport driver returns a VIDEO_MEMORY_INFORMATION structure in the VRP OutputBuffer.

Output Buffer Length

Input / Output Buffer

Input / Output Buffer Length

Status Block

If the miniport driver successfully maps the memory, it sets the Information member of the STATUS_BLOCK structure to sizeof(VIDEO_MEMORY_INFORMATION); otherwise, it sets this member to zero.

Requirements

   
Header ntddvdeo.h

See Also

STATUS_BLOCK

VIDEO_MEMORY

VIDEO_MEMORY_INFORMATION

VideoPortMapMemory