Re: passing options to grub in xen,openfirmware and efi

[Olaf Hering <olaf@aepfle.de>]

On Fri, May 08, Andrei Borzenkov wrote:

> On Fri, May 8, 2015 at 2:15 PM, Olaf Hering <olaf@aepfle.de> wrote:
> > On Fri, May 08, Vladimir 'phcoder' Serbinenko wrote:
> >
> >> That's not the plan which is pushed by xen guys. They propose to make grub
> >> stored on dom0 to just load grub from a predefined place in domU. This I.a.
> >> allows easier upgrade of bootloader for distros as they don't have to worry
> >> about dom0 having very old grub.
> >
> > Thats news, where was that proposed and discussed?
> http://xenbits.xen.org/docs/unstable/misc/x86-xenpv-bootloader.html

That is chainloading, and in that sense at a different layer.

The kernel= still looks just at the very first disk, or whatever disk is
returned by "search -f /path". If grub2 would start to look at extra= it
will be possible to select a configured disk.

I just browsed the code today, grub_xen_start_page_addr->cmd_line is
what /boot/chosen is in OF. Should be easy to add similar code to set
variables found in that cmdline. Its then up to the scripts running in
the binary referenced by kernel= to make use of such variables.

Olaf