Filesystems in uae are very dependent on interprocess-communication. While I really thought, I got this covered and right, somehow all those semaphores always got jammed somehow, resulting in a hang, as soon as the first AmigaOS filesystem packet reached the emulation code.
AROS semaphores are just different than Windows Events, which have quite some more possibilities. So I had a look at fs-uae (isn't open source nice?) and found out, that obviously they had to struggle, too, as they provide glib, pthreads and sdl semaphore based uae implementations.
So, we have SDL (and pthreads), too, so why not just use that code:
Not perfect, still hangs, but at least I now can see the workbench icon of my virtual work drive. This proves, that the problem was in the semaphore code, as with my own implementation, I got a hang much earlier.
Did I say, I have not much time at the moment? But this nags on my mind, so I *have* to do it.