ISO attach

[main--]

• blockdev-add https://github.com/qemu/qemu/blob/master/qapi/block-core.json#L3162
• https://github.com/qemu/qemu/blob/master/docs/usb-storage.txt#L50
  • device-add usb-bot,id=foo
  • device-add scsi-cd,bus=foo.0,lun=0,drive=mydrive
  • foo.attached = true

(Required for #126)

[oberien]

With #126 closed, is this issue still needed for Beta? I mean it would be a cleaner solution once this is stable and working, so the issue should still be open.

Or have we decided to always keep the current approach of having the cd always attached and always launch the exe from the cd? Then this can be closed.

[main--]

Still a relevant feature, I think. But much less important now that GA updates work.