Does QEMU support hfs floppy disk images?

[marbre]

I have some 800k and 1.44k hfs floppy images that qemu will not mount, e.g.

Code: Select all

./qemu-img info Tesserae.img 
image: Tesserae.img
file format: raw
virtual size: 780 KiB (798720 bytes)
disk size: 784 KiB

The monitor command 'change floppy0 /path/to/Tesserae.img' will load it, however it doesn't appear on the desktop.

[adespoton]

Floppy images are supported, but it has to be a real image, not just an 800k or 1.44MB partition image.

So DiskCopy 4.2 images should work; BII-created images likely won't.

[w16r]

Unless I’ve missed something obvious, I don’t think QEMU (as of 8.2.0-rc4) emulates a Macintosh floppy drive at all. As a result, it can’t present a floppy disk image—regardless of the image file format—in a way that would work with the Macintosh system software.

From the QEMU source code and commit history for hw/block/swim.c, it appears that the SWIM floppy disk controller implementation is still just a stub: it can satisfy the guest operating system that a controller is present, with no attached drive, but I don’t see any logic for reading or writing data. The Cocoa user interface does have “Change floppy0” and “Eject floppy0” items in the Machine menu, but floppy0 doesn’t seem to be connected to anything, unlike mtd0, hd1, and cd1 (in a typical configuration), for which the output of the “info block” command in the QEMU monitor includes “Attached to” messages showing connections to emulated devices in the QOM tree.

“Running qemu-system-m68k in macOS” mentions an A/UX boot floppy image, but it’s used with an emulated hard disk, and that’s a very special case. Ordinary Macintosh-formatted floppy disks don’t have a partition map, just a single HFS or MFS volume, and if a floppy disk image is presented as though it were a SCSI hard disk, the Macintosh system software ignores it, at least until you initialize the tiny “hard disk” with Apple HD SC Setup, which destroys any existing file system.

[Cat_7]

Indeed, Qemu does not support Mac floppy images.
That is why I created the small hard disk image with floppy content to be able to boot to the A/UX installer.

Best,
Cat_7