Can't(?) disable default floppy drive any more in qemu 6.0
This bug has been copied automatically from: https://bugs.launchpad.net/qemu/+bug/1923663
Reported by 'Adam Williamson' on 2021-04-13 :
There's a documented change in qemu 6.0: https://qemu-project.gitlab.io/qemu/system/removed-features.html#floppy- controllers-drive-properties-removed-in-6-0 where you can't configure floppy controller device properties with -global any more. However, there's a thing you could do with the old parameter which I can't figure out a way to do with the documented replacement. openQA passed exactly this argument: -global isa-fdc.driveA= and that has the effect of removing/disabling the default floppy drive/controller. If you just run `qemu-system-i686` (no other args) you'll see the VM briefly try to boot from a floppy drive; if you run `qemu-system-i686 -global isa-fdc.driveA=` (with an earlier version of qemu, obviously) you'll see it does not do so. I can't see a way to do this with `-device floppy`. Going by the docs, the equivalent should be: -device floppy,unit=0,drive= but that does not seem to have the same effect. If you run `qemu- system-i686 -device floppy,unit=0,drive=`, it still tries to boot from a floppy drive. I see there's a -nodefaults option that disables *all* default devices, but I don't think that's what we want here either. We might want the other default devices, we just don't want the floppy drive.