Re: [Qemu-devel] qemu/hw pckbd.c

[Jocelyn Mayer <l_indien@magic.fr>]

On Wed, 2007-04-18 at 14:06 +0100, Thiemo Seufer wrote:
> J. Mayer wrote:
> > On Mon, 2007-04-16 at 22:47 +0000, Thiemo Seufer wrote:
> > > CVSROOT:	/sources/qemu
> > > Module name:	qemu
> > > Changes by:	Thiemo Seufer <ths>	07/04/16 22:47:54
> > > 
> > > Modified files:
> > > 	hw             : pckbd.c 
> > > 
> > > Log message:
> > > 	Support it_shift for mmapped pckbd.
> > > 
> > > CVSWeb URLs:
> > > http://cvs.savannah.gnu.org/viewcvs/qemu/hw/pckbd.c?cvsroot=qemu&r1=1.19&r2=1.20
> > 
> > Thanks for the update.
> > Here's another small patch, based on the same idea of what is done for
> > the memory-mapped serial ports and which seems useful to implement some
> > targets: it may be needed not to register the I/O memory area in the
> > pckbd driver but let the caller do it.
> > Please take a look.
> 
> Actually, I thought about adding such a feature but then decided to
> defer it until it is actually needed. OTOH, with qemu handling mmio
> at page granularity it is likely needed sooner or later, so we could
> just declare it a standard implementation feature. I am ok with it 
> either way.

If you're interressed in such a feature, you may take a look of what
I've done in hw/ppc405_uc.c. There are some device sharing the same
memory page on those microcontrollers so I introduced a fake device
called mmio that allow to register multiple devices into a single page
in Qemu. I do use the serial_mm_init with the ioregister parameter set
to 0 for those designs.
This code may not be as generic as it would be if we want to make it a
standard Qemu function, but this may give a basis or ideas for it.

-- 
Jocelyn Mayer <l_indien@magic.fr>