Bug#776450: Xen PVH support for grub-xen in Buster

[Colin Watson]

On Sun, Jan 06, 2019 at 01:45:53AM +0100, Hans van Kranenburg wrote:
> Hm, so I have a PV (or PVH) domU in a test environment here, and I tried
> to use it in the Debian way of booting it.
> 
> If I install grub-xen-bin inside the domU then I get some stuff, but not
> update-grub. When I just also install grub2 it drags in more stuff, and
> then I end up with update-grub and a /boot/grub/grub.cfg file as result.

For the record, you wanted grub-xen rather than grub-xen-bin.

> I just copied *.mod that I got from my grub build (with the make blah
> shown before) into /usr/lib/grub/i386-xen_pvh of the domU,

I'd expect them to need to be in /boot/grub/i386-xen_pvh/ in order for
the boot loader to read them; grub-install copies modules there.
(However, a standalone image normally shouldn't need to read modules
from the guest anyway.)

> When trying to start that, I get:
> 
> Reading (memdisk)/boot/grub/grub.cfg
> 
> and then it exits back to the dom0 prompt and the domU is gone.

Seeing (memdisk) there suggests that $root is wrong.  I think that
putting your bootstrap configuration file in /boot/grub/grub.cfg in the
memdisk is a recipe for confusion; grub-xen-host puts it in /grub.cfg
instead, and generally hooks things up a bit differently.  You can
inspect debian/rules to see what it does.

Anyway, this sounds close enough that we can probably go for it and see
where it lands :-)

-- 
Colin Watson                                       [cjwatson at debian.org]