Question regarding parent capabilities

Hi,

for my porting efforts, I need to map the physical parent Capability into the protection domain of a newly created Child. To do so, I extended the Cpu_session with a method "native_thread", which --given a Genode::Capability-- will tell me the "physical" Capability of a thread. I map the parent capability into a known place of the child address space using the assign_parent method of Platform_pd. Unfortunately at this point I am stuck. Can you give me some advice on where assign_parent is called and how I can provide it with the correct capability (as my tries of implementing that in Process::Process have failed)?

Many thanks in advance, Steffen