[OpenBIOS] openfirmware boot partition layout

Mark Cave-Ayland mark.cave-ayland at siriusit.co.uk
Wed Feb 16 13:32:28 CET 2011

On 15/02/11 14:09, Dinar Valeev wrote:

> Hi,
> 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.

Note that you can get more debugging output from OpenBIOS if you load up 
KVM with a couple of extra options on the command line: -nographic 
-prom-env='auto-boot?=false'. This will enable you to see the debug 
output, and also drops you to the Forth command prompt rather than 
trying to boot the device automatically.

You can then try manually booting a PPC partition, e.g.

boot cdrom:1
boot disk:2


Or even browse some of the filesystem contents to see if the FS is 

dir cdrom:1\
dir disk:2\

> 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.



Mark Cave-Ayland - Senior Technical Architect
PostgreSQL - PostGIS
Sirius Corporation plc - control through freedom
t: +44 870 608 0063

Sirius Labs: http://www.siriusit.co.uk/labs

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