writing my own filesystem for L4

Hello. I'm going to write a filesystem for L4, using the tmpfs (l4/pkg/tmpfs) as a starting point. However, I would like to know whether there are any tools I could use to test the filesystem. The tool I would love to have should display all registered filesystem and should allow me to walk through filesystem's directory trees. Is there such a tool or example application? Are there any packages in L4 which use VFS layer at all? regards, Michal. -- Michal Schulz