APIC trigger mode

Adam Lackorzynski adam at os.inf.tu-dresden.de
Thu Mar 15 22:35:04 CET 2012

On Tue Mar 13, 2012 at 13:02:36 +0100, Sebastian Sumpf wrote:
> I have a question regarding the APIC-interrupt mode settings on x86. I
> see that one has to set the mode externally in Fiasco.OC using the
> 'l4_icu_set_mode' call. Also I had a look at Nova which seems to program
> these modes from within the kernel, using edge/high for IRQ 0-15 and
> level-low for IRQ 16-23. Would that be a valid assumption to program the
> modes for Fiasco.OC x86 also, or is there an other way to find out the
> interrupt-trigger modes of IRQs (other than the ones found in
> ACPI-MADT)? Why is it necessary to set these modes outside the kernel?

Generally, this depends on the device and thus it's configurable for a
driver. If some combination is not possible then it should just be
ignored/fail. Does this help?

Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/

More information about the l4-hackers mailing list