Certain devices, particularly devices that perform DMA, require that their buffers reside in physically contiguous memory in the CPU's address space. In addition, these devices must access the memory buffers using the actual physical address, rather than by the virtual address that is used by a Windows or an RTSS process.
The RtAllocateContiguousMemory, RtAllocateContiguousMemorySpecifyCache, and RtGetPhysicalAddress functions are used to allocate physically contiguous memory and to translate the virtual address of the memory to a physical address, respectively.
Topics:
