Re: [QUESTION] qemu: how to control the switch of floppy drive

["Xu, Yanfei" <yanfei.xu@windriver.com>]

On 4/9/21 3:10 PM, Philippe Mathieu-Daudé wrote:
> [Please note: This e-mail is from an EXTERNAL e-mail address]
> 
> Hi,
> 
> On 4/9/21 8:48 AM, Xu, Yanfei wrote:
>> How can I disable the floppy controller drive when I boot a VM by qemu-
>> system-x86_64? I did not specify any arguments about floppy, but after
>> the qemu boots up, linux always can detect floppy drive and then
>> modprobe the matched floppy.ko.
>>
>> qemu version: v5.2
>>
>> command line:
>>
>> qemu-system-x86_64 -device virtio-net-
>> pci,netdev=net0,mac=52:54:00:12:34:02 -netdev
>> tap,id=net0,ifname=tap0,script=no,downscript=no -object rng-
>> random,filename=/dev/urandom,id=rng0 -device virtio-rng-pci,rng=rng0
>> -drive file=/path/to/images/qemux86-64
>> /qemux86-64.ext4,if=virtio,format=raw -usb -device usb-tablet   -cpu
>> core2duo -enable-kvm -m 512  -pidfile /path/to/pidfile_4167420 -m 512
>> -snapshot -serial mon:vc -serial null  -kernel /path/to/qemux86-64
>> /bzImage.bin -append 'root=/dev/vda rw  mem=512M
>> ip=192.168.7.2::192.168.7.1:255.255.255.0 oprofile.timer=1
>> printk.time=1'
>>
>> As I konw BIOS can control the switch of floppy controller on a real
>> hardware, But how can I do it on qemu? And does the qemu enable that by
>> default?
> 
> See
> https://gitlab.com/qemu-project/qemu/-/blob/master/docs/qdev-device-use.txt#L105
> 
> * if=floppy
> 
>    -device floppy,unit=UNIT,drive=DRIVE-ID
> 
>    Without any -device floppy,... you get an empty unit 0 and no unit
>    1.  You can use -nodefaults to suppress the default unit 0, see
>    "Default Devices".

I see. Thanks for your link and detailed explanation. :)

Thanks,
Yanfei

> 
> Regards,
> 
> Phil.
>