[coreboot] AMD platform: IO-APIC => Local APIC delivery modes

Andriy Gapon avg at FreeBSD.org
Mon Oct 10 09:32:27 CEST 2016

On 09/10/2016 23:41, Rudolf Marek wrote:
> Great, so there is a bug! Do you have some USB image I can try on more recent
> AMD system (with Hudson chipset). Or we can try to report this to AMD, but I
> have read somewhere that the new chipsets are done by Asmedia.

I did most of the testing using two small programs, one to examine the IO-APIC
redirection table and the other to write its entries:
Another thing required is an interrupt that can be reliably triggered in a
controllable fashion (like a mouse interrupt or a timer interrupt).  In my case
I used an interrupt from the watchdog timer.

So, I would just directly re-program a pin corresponding to the interrupt and
then trigger the interrupt and see what happens.

An example:
$ ioapic_wr 3 0xff00000000000300

Andriy Gapon

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