The biggest problem is that the ASIO API is defined in the asio.h
header file distributed by Steinberg in their ASIO SDK, and that the
license explicitly forbids the distribution of any component by a third
party. I imagine that this situation is not new to the Wine project
and similar to other SDKs needed. I have a header file which I have
created by compiling the driver without including asio.h, and then
typing in the needed defines and structures while consulting asio.h.
The header makes the driver work in both 32 and 64 bit wine.