Help: ICE_ICELIB_PIC_MAPFILE
Prepares a Midas file/buffer for DMA transfers
Function PIC_MAPFILE - Prepares a Midas file/buffer for DMA transfers
PIC p Handle to Device
DMAMAP map DMAMAP structure to contain virtual and physical pointers
HEADER hcb Header Control Block of a Midas file
int mode Access mode (1=allocate, -1=deallocate)
Prepares a Midas file for DMA transfers. It the file is on a RAMDISK the
start and count map to the actual disk address. If not, a memory buffer
matching the file size is allocated and mapped to DMA address space.
If memory is not mappable (or mode=2,-2) paddr is set to zero and a
virtual buffer is allocated but not mapped. This buffer is usable for
non-DMA access which limits speeds to ~10Mby/sec.
The map structure is inputs to the PIC_DMASETUP routine. These numbers
are checked by the driver to ensure the addresses are valid before the DMA is
started.