Hi Christian,
For Genode::raw() to work on Fiasco.OC, the component needs the debug capability to access the kernel debugger for output. This may be a robustness/security risk in production systems and is, therefore, not enabled by default. The access can be enabled by adapting the code [1] and after recompilation all components can access the Fiasco kernel debugger.
Your solution worked, thanks for the help!
Cheers, Simon Himmelbauer