[Qemu-devel] Drive success FAT16, NTFS, failure with FAT32

[Tom Marble <tmarble@info9.net>]

Fabrice:

I have been able to configure qemu (from CVS yesterday)
to use the following drives:

In each case I used bximage (interactively) to create
the raw image files (which I left to the Windows installers
to partition and format).  I probably could/should
have used qemu-img instead.

FAT16
  503 MB
  Type: 0x0e   W95 FAT16 LBA
  Installed Windows 98 successfully

NTFS
  2000 MB
  Type: 0x07  HPFS/NTFS
  Installed Windows XP successfully

I was unsuccessful, however, in creating FAT32 filesystems,
even those < 512 MB.
Using fdisk to set /dev/hda1 to type 0x0b WIN95 FAT32
and creating the filesystem with mkdosfs -F 32
did create a disk that was recognized by the Windows 98
installer.  Windows complained about bad clusters.

Using type 0x0c WIN95 FAT32 (LBA) and formatting the
disk made the Windows 98 installer happy.
However on the first reboot after installation
the BIOS complained of a Disk I/O Error.
Once it actually got farther and said Booting... but then
just hung.

I made various attempts at adding -hdachs arguments
but none succeeded in making the FAT32 disk recognized.
I have not looked at the code that examines the MBR
or trys to mount the partition based on the
type, but I suspect that's the next place to look.

I have to say I am *very* impressed with qemu!
In my debugging I tried to see if bochs would work
with FAT32 -- and it didn't (same BIOS as qemu) -- but it ran much,
much slower (probably the 4x slower people have mentioned).
One can imagine using the bochs BIOS to debug
ACPI and PXE related issues as well.

Merci pour cet excellent logiciel!

--Tom