Comment # 21 on bug 926795 from Olaf Hering

(In reply to Michael Chang from comment #20)
> (In reply to Olaf Hering from comment #19)
> 
> > I think the example can be extended to look first for a new
> > /boot/x86_64/grub2-xen/grub.cfg on an iso image. If its not found it may
> > just look for kernels as above. Whatever we do, such custom grub.cfg should
> > be encapsulated in our default grub.xen. Looks like a useful addition.
> 
> I think your concern is that default grub.xen should also work on old iso
> image without /boot/x86_64/grub2-xen/grub.cfg file. Right ?

Yes, thats desirable. 

What about  this logic:

if /boot/x86_64/grub2-xen/grub.cfg or /content|/kernel|/initrd exist:
 show a menu which allows to boot from hard disk or do an install (two items)
 default is boot from hard disk, with timeout of some seconds.
else
 boot from hard disk


The relevant script will be included in grub.xen. Not sure how it is build. I
assume it will be easy to create such a custom image during the build process.