Re: EFI and multiboot2 devlopment work for Xen

[Ian Campbell <ian.campbell@citrix.com>]

On Tue, 2013-10-22 at 18:01 +0200, Daniel Kiper wrote:
> On Tue, Oct 22, 2013 at 03:42:42PM +0000, Woodhouse, David wrote:
> > On Tue, 2013-10-22 at 16:32 +0100, Matthew Garrett wrote:
> > >
> > > There are two problems with this:
> > >
> > > 1) The kernel will only boot if it's signed with a key in db, not a key
> > > in MOK.
> > > 2) grub will read the kernel, but the kernel will have to read the
> > > initramfs using EFI calls. That means your initramfs must be on a FAT
> > > partition.
> > >
> > > If you're happy with those limitations then just use the chainloader
> > > command. If you're not, use the linuxefi command.
> >
> > Well, we're talking about booting the Xen hypervisor aren't we?
> >
> > So yes, there are reasons the Linux kernel uses the 'boot stub' the way
> > it does, but I'm not sure we advocate that Xen should emulate that in
> > all its 'glory'?
> 
> Right, I think that sensible mixture of multiboot2 protocol (it is needed
> to pass at least modules list to Xen; IIRC, linuxefi uses Linux Boot protocol
> for it) with extension proposed by Vladimir and something similar to linuxefi
> command will solve our problem (I proposed it in my first email). Users which
> do not need SB may use upstream GRUB2 and others could use
> 'multiboot2efi extension'.

Are you (going to be) in Edinburgh? Matthew was just explaining a bunch
of this stuff to me, it might be useful for you to get it from the
horses mouth instead of laundered through my brain (which is a bit
addled afterwards ;-)).

Ian.