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

["andrzej zaborowski" <balrogg@gmail.com>]

On 04/12/2007, Paul Brook <paul@codesourcery.com> wrote:
> On Tuesday 04 December 2007, andrzej zaborowski wrote:
> > On 04/12/2007, Paul Brook <paul@codesourcery.com> wrote:
> > > > Log message:
> > > >       Always create an SD bdrv, so that PXA and OMAP boards can boot
> > > > with no card inserted again.  Eventually SD, CDROM and floppy should
> > > > all be registered conditionally depending on machine.
> > >
> > > This seems the wrong way to solve this problem. The SD emulation should
> > > be able to cope with no device being present.
> >
> > The bdrv's represent the concept of "drive" rather than "media", and
> > also in the case the bdrv must be present whenever there is a SD slot,
> > not an SD card (so that monitor command change and eject can be used).
> > I agree that not all machines have an SD slot, as not all machines
> > have a cd-rom drive or floppy drive.
>
> Right, but I think you're going in the wrong direction. Most scsi interfaces
> do support hotplug of devices. For USB mass storage the whole controller is
> hotplug. Pre-allocating all possible devices simply doesn't scale.

We don't pre-allocate all possible devices, only the "drives" which
are integral part of the machine (as is the case of the SD slot in a
Zaurus, soldered to the PCB). New bdrv's can still be added and
removed in runtime for hotplugged devices and I have no intetion to
change that.

If you want to use the hotplugging-like mechanism for inserting
removable media like SD, CD or floppy, that would mean scrapping the
whole bdrv_is_removable(), bdrv_is_inserted(), bdrv_media_changed()
api.
Regards