L4Linux Driver + L4_ipc

Hello again,


as mentioned before i'm writing a char module for L4linux.

I want the L4Linux driver to communicate over l4_ipc to another L4-Task.

Well, there's a compiler error:

   Building modules, stage 2.
   MODPOST 1 modules
ERROR: "l4_utcb_wrap" [drivers/char/myDrv.ko] undefined!


This appears, when trying to write in mr[].

     l4_msg_regs_t* mregs = l4_utcb_mr_u(utcb);
     mregs->mr[0] = 23; // if i comment this line, build works.


I doesn't crash at runtime, it just don't compile.
Any idea?


BTW: Adam made a hint to use L4XV_FN* wrappers.
When to use them, and what are they for?



Thanks,
ba_f