Configuring Memory Segment Types

The video memory manager (VidMm) and display hardware only support certain types of memory segments. The kernel-mode display miniport driver (KMD) can therefore only configure segments of those types.

The KMD can configure memory-space segments and aperture-space segments, which are different in that:

• A memory-space segment consists of a medium that holds the bits of an allocation.

• An aperture-space segment is a virtual address space.

When a range in a memory-space segment is allocated, actual memory is allocated. When a range in an aperture-space segment is allocated, the virtual address space is redirected to physical pages that are allocated independently from either a video memory pool or system memory.

The KMD can configure the following types of memory segments:

• Linear Memory-Space Segments

• Linear Aperture-Space Segments

• AGP-Type Aperture-Space Segments