Re: qemu broke booting of old RedHat floppies

[Thomas Huth]

On 20/01/2021 16.11, Michael Tokarev wrote:
> As someone noticed on IRC, old (2.x) RedHat floppies does not boot
> in current qemu.  When qemu is booted from floppy image at
>   https://archive.org/details/RedHatLinuxBootDisk521998
> (download the "ISO image" link there, it really is an 1.44 floppy),
> seabios says Boot failed and that's it.
>
> I run git bisect with it, knowing that qemu 2.1 works fine, and
> it pointed out to this commit which is oldish qemu-2.5+:
[...]
> Now, I don't even know where to put that "type=144/288/auto" thing,
> I tried this:
>
>   -drive 
> file=RedHatLinuxBootDisk521998.disk1of1.img,if=floppy,format=raw,type=144
>
> but it says that format=raw does not support "type=144" option.

Try:

 qemu-system-x86_64 -drive 
if=none,file=RedHatLinuxBootDisk521998.disk1of1.img,format=raw,id=dr1 
-device floppy,drive-type=144,drive=dr1

> And it's even more: I don't remember which size should be an 1.44Mb floppy :))
> The file size of that image is 1492992 bytes which does not look like it is of
> standard size, but I can't find which size it should be.

As mentioned on IRC already, it's likely a disk with 81 tracks instead of 80 
tracks, so it's bigger than the usual 1.44 MB floppy disk images and thus 
QEMU likely misdetects it by default.

 Thomas