Input driver configuration and use in L4Re

Paul Boddie paul at
Wed May 23 00:21:23 CEST 2018

On Wednesday 16. May 2018 00.37.32 Paul Boddie wrote:
> But I cannot figure out how to have the client create the interrupt and
> send it to the server, which would be a prerequisite for implementing the
> necessary interrupt mechanism for events, as far as I can tell. Presenting
> a capability instance (L4::Cap<L4::Irq>) to the IPC stream, which should
> then result in a Snd_fpage instance being queued, just causes the
> L4_IPC_SEMSGCUT ("Cut send message") condition.

I think I figured out what causes this particular error condition: the 
Registry_server class needs parameterising with Br_manager_hooks instead of 
the default hooks. Providing a parameterised Demand_t class amongst the 
template parameters for Kobject_t seems to then allocate space for an incoming 
capability. These two details are in some examples, but their purposes aren't 
clearly stated.

Unfortunately, I can't get the sent capability to be recognised. Reading a 
Snd_fpage instance from the IPC stream seems successful, but the item is not 
considered valid. I'm wondering if I need to declare something somewhere else, 
here, and perhaps pkg/examples/sys/map_irq holds the key to this, but I don't 
really follow the mechanism.


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