[OpenBIOS] openfirmware boot partition layout

Andreas Färber andreas.faerber at web.de
Fri Feb 18 22:59:31 CET 2011


Hi Dinar,

Am 16.02.2011 um 14:23 schrieb Dinar Valeev:

> On Wed, Feb 16, 2011 at 1:32 PM, Mark Cave-Ayland
> <mark.cave-ayland at siriusit.co.uk> wrote:
>> On 15/02/11 14:09, Dinar Valeev wrote:
>>
>>> I'm playing with kvm on powerpc (I have LPAR'ed IBM Power5 machine).
>>>
>>> I have a couple of disk images which are working perfectly. (I've
>>> tested it by deploying it using VIO server with usual dd command
>>> directly to LPAR disk)
>>>
>>> But when I'm trying to attach same image as qemu (with KVM enabled)
>>> disk. VM won't boot. It just stuck on openbios banner.
>>
>> Okay - first question to ask is this: which version of KVM and  
>> which SVN
>> revision of OpenBIOS are you using? There has a been a lot of work  
>> in this
>> area last year for example.
>
> I'm using kvm with 2.6.38-rc3-67365-g7a67422 kernel
>
> mine qemu version is:
> QEMU emulator version 0.14.50, Copyright (c) 2003-2008 Fabrice Bellard
>
> I believe this is most recent version.

It may be, but its OpenBIOS version has not been updated for a while.  
For ppc64 you still need an SVN version.

> My qemu command is:
> ./ppc64-softmmu/qemu-system-ppc64 -enable-kvm -drive
> file=/root/k0daz_ppc_lvm_appliance.ppc64-1.0.1.raw -cpu power4
> -nographic -prom-env 'auto-boot?=false'
>
> Once I'm in OF prompt I've tried to invoke:
> 0 > dir disk:1\ pc-parts: Unable to determine filesystem
> ok
>
> If I'm trying to boot VM with one you proposed. VM just hangs.
>
>>> I have another image with old mac partition table (which is  
>>> working under
>>> qemu)
>>>
>>> So I have actually two questions:
>>> 1) Is booting from PReP partition (type 0x41) is supported? (PReP  
>>> just
>>> consists raw copy of yaboot binary)
>>>
>>> 2) When VM have LVM root then it required to have FAT partition  
>>> (type
>>> 0x06) with kernel, initrd, yaboot and its config.
>>> Does this scenario supported as well?
>>>
>>> Here is usual partition setups I have:
>>> non lvm setup:
>>> Number  Start   End     Size    Type     File system  Flags
>>>  1      32.3kB  8225kB  8193kB  primary                
>>> boot, , , , , ,
>>> , , , type=41, prep,
>>>  2      8225kB  897MB   888MB   primary   
>>> ext3         , , , , , , , ,
>>> , type=83, ,
>>>
>>> lvm setup:
>>> Number  Start   End     Size    Type     File system  Flags
>>>  1      32.3kB  49.4MB  49.3MB  primary  fat16         
>>> boot, , , , , ,
>>> , , , type=06, ,
>>>  2      49.4MB  979MB   929MB   primary               , , , , ,  
>>> lvm, ,
>>> , , type=8e, ,
>>>
>>> I'll glad to provide additional information or participate in  
>>> testing
>>> in the future.
>>
>> Andreas is the person most likely to know the current status of PPC  
>> support.
> Andreas, have you tried such scenarios?

No. I don't have a KVM setup.

Emulating a PReP machine (-M prep) I didn't get too far.
That was before Hervé's NVRAM patch though and booting ELF OpenBIOS  
with -M prep needs QEMU patches:
http://repo.or.cz/w/qemu/afaerber.git/commitdiff/b73968204a262e36a33da3c33ddd43873f67d9fa

Regards,
Andreas


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