This is interesting!! Please, can you tell which kind of Linux installation do you use? When you install XDSL, you can make a "Frugal" installation (the small one, around 50 MB) or a Loopback installation (around 200 MB). Probably the best option is the Loopback installation because it is enabled to do lots of changes in it. Making changes in the Frugal installation is harder. Sadly, I have the Frugal installation in my Xbox (I made it years ago, when I didn't know about this).
Well, as far as I know, DSL has many common things with Debian. We have different options to test:
1) Run Wine (I read that you achieved to do it) and Yabause for Windows! Maybe it is a bit slower...
2) Try to compile the source code of Yabause in a PC with DSL (or Debian?) and FTP the executable to the Xbox. Or even try to compile the code in the Xbox, in XDSL!! If anyone manages to do it, I'm sure that this is the best option as far as performance is related
3) Try to install the package. I don't know if it is possible. I know that the package managent is done in the MyDSL option, but I have not tested it. I tested it in DSL (in a computer) but not in the Xbox... This option seems to be more difficult, as the package seems to be built for Debian, and not for DSL...
Great work xRaVeNx!!