The sn driver isn't UCODE sourceless. While it is true there's an
binary FPGA image that's in an include file in this directory, that
include file isn't actually used. It is only for certain Trump Cards
that we don't yet support. When support was anticipated for them, we
got permission to include the required FPGA image in our sources under
the BSDL, but didn't start actually including the file. This was done
to provide a public paper trail for this file.