Re: [Qemu-devel] [PATCH 3/4] Add support for HPET periodic timer.

Luca
2007-08-21T19:40:57Z

On 8/21/07, Matthew Kent <mkent-rTVjrLRGJfNWk0Htik3J/w@public.gmane.org> wrote:
> On Sat, 2007-18-08 at 01:11 +0200, Luca Tettamanti wrote:
> > plain text document attachment (clock-hpet)
> > Linux operates the HPET timer in legacy replacement mode, which means that
> > the periodic interrupt of the CMOS RTC is not delivered (qemu won't be able
> > to use /dev/rtc). Add support for HPET (/dev/hpet) as a replacement for the
> > RTC; the periodic interrupt is delivered via SIGIO and is handled in the
> > same way as the RTC timer.
> >
> > Signed-off-by: Luca Tettamanti <kronos.it-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>
> I must be missing something silly here.. should I be able to open more
> than one instance of qemu with -clock hpet? Because upon invoking a
> second instance of qemu HPET_IE_ON fails.

It depends on your hardware. Theoretically it's possible, but I've yet
to see a motherboard with more than one periodic timer.

"dmesg | grep hpet" should tell you something like:

hpet0: 3 64-bit timers, 14318180 Hz

Luca