Re: [PATCH 2/2] via-ide: Also emulate non 100% native mode

[Artyom Tarasenko <atar4qemu@gmail.com>]

Hi guys,

On Sun, Mar 1, 2020 at 6:54 PM Mark Cave-Ayland
<mark.cave-ayland@ilande.co.uk> wrote:
>
> On 01/03/2020 16:42, BALATON Zoltan wrote:
>
> >> The other part I'm not sure about is that I can't see how via_ide_set_irq() can ever
> >> raise a native PCI IRQ - comparing with my experience on cmd646, should there not be
> >> a pci_set_irq(d, level) at the end?
> >
> > According to my tests with several guests it seems the via-ide does not seem to use
> > PCI interrupts as described in the previous reply, only either legacy IRQ14 and 15 or
> > one ISA IRQ line set by a config reg in native mode (except on Pegasos2). This may be
> > due to how it's internally connected in the southbridge chip it's part of or some
> > other platform specific quirk, I'm not sure.
>
> I think this is the key part here: how does via-ide switch between legacy and native
> mode? For CMD646 this is done by setting a bit in PCI configuration space, and I'd
> expect to see something similar here.

I haven't read the complete discussion yet, but  checked how it's done
in OFW. OFW did definitely work on via boards. Surprisingly OFW
Switches all IDE boards into native mode the same way:

my-space 9 + dup " config-b@"  $call-parent
    05 or  swap  " config-b!"  $call-parent

HTH

-- 
Regards,
Artyom Tarasenko

SPARC and PPC PReP under qemu blog: http://tyom.blogspot.com/search/label/qemu