Hello Johannes, On Tue, Mar 13, 2018 at 01:36:09PM +0100, Johannes Kliemann wrote: > I'm currently implementing the IRQ session on base-linux. > If I understood the Foundations book correctly interrupts are waiting in > a separate thread that locks when it is waiting and continues (and calls > the handler) once an interrupt is triggered.
The core-internal implementation depends on the base platform. On NOVA and FOC, the Irq_object (which is a thread) is never started, ie., does not execute an entry function. Other platforms (e.g., OKL4) use the Irq_object thread to implement a interrupt-wait-and-signal loop. > According to this I have implemented a kernel module [1] that triggers > interrupts via reads on a device file. The interrupt can be registered > via ioctl on the file descriptor and the a blocking read is called that > returns once the registered interrupts has been triggered. > > I have looked into the implementations of base-nova and base-hw but > didn't completely understand it. As far as I understood the session > component implements the session and only requires the interrupt number > and a signal handler. > The Irq_object implements the waiting thread but I didn't see where it > is waiting for the interrupt. > Also as far as I could see it the actual interrupt capability stays > inside the session in core and only the signal handler capability is > passed to the component. I suggest you refer to OKL4 base-okl4/src/core/irq_session_component.cc and implement an Irq_object working similarly with a entry() function that uses Irq_object::_wait_for_irq() (which blocks in read(dev_fd)) and signals IRQ occurence by Genode::Signal_transmitter(_sig_cap).submit(1) > Is my understanding of this correct? And is there any further > documentation on this? Unfortunately, there's only few documentation of the core internals. To get up-to-date information I suggest looking at the code and asking here or even on Freenode http://webchat.freenode.net/?randomnick=1&channels=%23genode&uio=d4 Regards -- Christian Helmuth Genode Labs https://www.genode-labs.com/ · https://genode.org/ https://twitter.com/GenodeLabs · /ˈdʒiː.nəʊd/ Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ genode-main mailing list genode-main@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/genode-main
