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Re: qemu broke booting of old RedHat floppies
From: |
Alexander Bulekov |
Subject: |
Re: qemu broke booting of old RedHat floppies |
Date: |
Wed, 20 Jan 2021 10:39:59 -0500 |
On 210120 1811, 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+:
>
> commit 4812fa27fa75bce89738a82a191755853dd88408
> Author: John Snow <jsnow@redhat.com>
> Date: Fri Jan 22 15:51:05 2016 -0500
>
> fdc: change auto fallback drive for ISA FDC to 288
>
> The 2.88 drive is more suitable as a default because
> it can still read 1.44 images correctly, but the reverse
> is not true.
>
> Since there exist virtio-win drivers that are shipped on
> 2.88 floppy images, this patch will allow VMs booted without
> a floppy disk inserted to later insert a 2.88MB floppy and
> have that work.
>
> This patch has been tested with msdos, freedos, fedora,
> windows 8 and windows 10 without issue: if problems do
> arise for certain guests being unable to cope with 2.88MB
> drives as the default, they are in the minority and can use
> type=144 as needed (or insert a proper boot medium and omit
> type=144/288 or use type=auto) to obtain different drive types.
>
> As icing, the default will remain auto/144 for any pre-2.6
> machine types, hopefully minimizing the impact of this change
> in legacy hw to basically zero.
>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: John Snow <jsnow@redhat.com>
> Message-id: 1453495865-9649-13-git-send-email-jsnow@redhat.com
>
> 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.
>
There is a drive-type=144 option to -device floppy. Maybe that's where
it goes:
-drive id=fdc1,... -device floppy,drive=fdc1,drive-type=144
> 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.
>
> Thanks!
>
> /mjt
>