I'm going to implement an SPI for my own hardware (maybe virtual). As I found (maybe I mistake) when an application calls WFSOpen, XFS calls WFPOpen in SPI. But this "in SPI" means where? Maybe I should give the address of the dll file in which WFPOpen is found somewhere in registry. I also think that the dll path should be given in HKLM\XFS\Service_Provider\[device name]\DllName. Is it so and is it enough? Is XFS sensitive to this registry path and key and uses it to find where is the SPI? I've done above, but I get WFS_ERR_SERVICE_NOT_FOUND. It seems that XFS doesn't look for the function in the dll. What can be wrong?