Re: [Xen-devel] [PATCH v2 22/23] x86: make Xen early boot code relocatable

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Aug 28, 2015 at 02:22:46AM -0600, Jan Beulich wrote:
> >>> On 27.08.15 at 19:56, <42656e@gmail.com> wrote:
> >> If you advocate direct booting ( no boot loader)  on production machines I
> > wont argue much, as long as there is good recovery tools to deal with
> > failed boots (grub does this very well, I am not aware of anything
> > comparable that is pure efi). however the other use case which care more
> > about is dual booting. I am a novice when it comes to Xen, although
> > otherwise competent. The test machines I have for playing with Xen are also
> > used for other tests, some of which require raw hardware support, so I want
> > the ability to use a boot menu.
> 
> All EFI systems that I've seen so far have a boot manager. Are you
> saying there are vendors who remove that?

Worst. There are some where the boot managers <cough>certain families of 
AMI based BIOSes</cough> which delete all but the last boot entry to
only have _one_ boot entry per ESP. No DualBoot for you!

The 'boot manager' in question is an boot entry (F8 or F12), which does not
allow any changes (change the parameters, etc) - just select the entry.

Furthermore my recollection is Microsoft has a 'boot configuration manager'
after EFI boots - you hit F8 and you can select which options you want to
boot Windows with.

We need that functionality and we can't depend on EFI getting it right - 
hence need GRUB. It would be fantastic if everybody fixed their EFI firmware
but since some of these for SMI have 'O.E.M vendor should
put information here' (or whatever it says) - it makes me think they
don't care the sligthest after the product has been released.

And I am not comfortable to say 'GRUB2+Xen cannot run on this hardware
because your firmware vendor is not following the EFI spec in spirit.'

Now that said - do you have suggestions on how to make this work
with GRUB in the picture?

Thank you.

> Jan
> 
> 
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