Re: [Qemu-devel] qemu-kvm 0.15.0 boot order not working

[Michael Tokarev <mjt@tls.msk.ru>]

On 29.08.2011 15:42, Peter Lieven wrote:
> On 29.08.2011 13:21, Ottavio wrote:
>> On 29 August 2011 11:12, Peter Lieven<pl@dlh.net>  wrote:
>>> Hi,
>>>
>>> when I specify something like
>>>
>>> qemu -boot order=dc -cdrom image.iso -drive file=img.raw,if=virtio,boot=yes
>>>
>>> or
>>>
>>> qemu -boot order=n -cdrom image.iso -drive file=img.raw,if=virtio,boot=yes
>>>
>>> with qemu-kvm 0.15.0
>>>
>>> it will always directly boot from the hardrive and not from cdrom or
>>> network.
>>> is this on purpose? the behaviour was different in earlier versions.
>>> If i omit the boot=yes in the drive specification the "-boot order"
>>> parameter is working
>>> as expected.
>> This is the qemu doc file:
>> http://qemu.weilnetz.de/qemu-doc.html
>>
>> and this is qemu-kvm man page:
>> http://linux.die.net/man/1/qemu-kvm
>>
>> I have never seen the boot=yes as an option to the argument -drive. I
>> have also checked on previous versions of qemu and I haven't seen it
>> so I'm puzzled why it should have worked in the first instance.
> -drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]
>        [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]
>        [,cache=writethrough|writeback|none|unsafe][,format=f]
>        [,serial=s][,addr=A][,id=name][,aio=threads|native]
>        [,readonly=on|off][,boot=on|off]
>                 use 'file' as a drive image
> 
> you cannot boot e.g. from a virtio_blk device without this flag.

It is possible since 0.13 or 0.14.  Actually it's seabios thing,
it got real support for virtio drives awhile back, before it was
indeed possible only using boot=on drive option.

> it seems that the if the extboot option rom is loaded the
> specified boot order is ignored.

And yes this is the case.  the -boot tells bios about normal
boot order, and with extboot you overwrite that.  That's how
booting works for stuff which is not supported by bios.

/mjt