Re: [Qemu-devel] [Qemu-ppc] Qemu boot device precedence over nvram boot-device setting

[Gleb Natapov <gleb@redhat.com>]

On Thu, Sep 27, 2012 at 04:04:54PM +0530, Nikunj A Dadhania wrote:
> On Thu, 27 Sep 2012 12:13:05 +0200, Gleb Natapov <gleb@redhat.com> wrote:
> > On Thu, Sep 27, 2012 at 03:35:53PM +0530, Nikunj A Dadhania wrote:
> > > 
> > > If the user does not set bootindex, qemu would decide the bootindex?  
> > > 
> > No. Firmware decides. QEMU just tells to firmware that it does not have
> > bootindex.
> 
> Ok. That should work in that case, we need to make sure that bootindex
> is being send via device-tree. I do not see such code in place
> currently.
> 
It is sent to firmware via PV fw_cfg interface in "bootorder" file.

> > 
> > > If it does, there will be a default bootindex. Then the problem still
> > > remains, qemu decided the boot-order, in which case we would want to
> > > pick the nvram based setting. This is again difficult to distinguish.
> > > 
> > > > There is nothing "blurry" about OF device
> > > > path. The problem is that it works reasonably well with legacy BIOS
> > > > since it is enough to specify device to boot from, but with EFI (OF is
> > > > the same I guess) it is not enough to point to a device to boot from,
> > > > but you also need to specify a file you want to boot and this is where
> > > > bootindex approach fails.
> > > 
> > > By file I suppose you mean OF device-path. 
> > > 
> > No. By file I mean a file on dedicated EFI FAT partition that EFI loads
> > during boot.  I do not know if OF has something similar.
> > 
> No, it just needs the device-path. Rest it figures out.
> 
> Regards
> Nikunj

--
			Gleb.