Originally Posted by gilgamesh
Sounds awsome, but what are those DOS Packets?
The quick and dirty explanation is that while most other "stuff you communicate with" in AmigaOS are devices that share a common base interface, filesystem handlers have their own separate system consisting of completely differently structured messages that dos.library use to pass requests (for things like reading, writing, getting directory contents etc.) to them.
AROS originally went with implementing filesystem handlers as devices, which might arguably be more consistent with the rest of the AmigaOS API but which is quite incompatible with AmigaOS itself. In retrospect it wasn't a great idea as it made it far harder to port filesystems and the gains were comparatively small, and so there's been a long standing goal of fixing this incompatibility.
For the M68k port they're now actually going ahead and fixing it. Eventually those changes will hopefully make their way into the other AROS versions too.