[oe] RFC: Kexec Cmdline Support

[Hans Henry von Tresckow]

On 9/26/07, Uli Luckas <u.luckas at road.de> wrote:
>
> On Tuesday, 25. September 2007, Hans Henry von Tresckow wrote:
> > On 9/25/07, Uli Luckas <u.luckas at road.de> wrote:
> > > On Monday, 24. September 2007, Hans Henry von Tresckow wrote:
> > > > (sorry for crossposting this,but I think more of the interested
> parties
> > > > read oe-devel then angstrom-devel)
> > > >
> > > > A while back, mwester made some patches to add the ability to modify
> > > > the cmdline when using kexec to load a kernel. I did some testing on
> > > > poodle
> > >
> > > and
> > >
> > > > posted the results on the bug tracker
> > > > (http://bugs.openembedded.org/show_bug.cgi?id=2969)
> > > > I was wondering what the rest of the developers think of these.
> > >
> > > Hi Henry,
> > > A while back I posted a different approach [1] to this mailing list
> for
> > > review. To bad, there have not been any comments.
> > >
> > > The differences of my approach in contrast to mwester's approach have
> > > been discussed on the arm kernel mailing list. If there is any
> interest
> > > in this (userspace) approach at all, I will improve on the known
> problems
> > > (like hard
> > > coded ATAG base address).
> > >
> > > I'd really appreciate feedback from the developers.
> > >
> > > Best regerds
> > > Uli
> > >
> > > 1)
> > >
> > >
> http://lists.linuxtogo.org/pipermail/openembedded-devel/2007-August/00284
> > >0.html
> > >
> > > --
> > >
> > > ------- ROAD ...the handyPC Company - - -  ) ) )
> > >
> > > Uli Luckas
> > > Software Development
> > >
> > > ROAD GmbH
> > > Bennigsenstr. 14 | 12159 Berlin | Germany
> > > fon: +49 (30) 230069 - 64 | fax: +49 (30) 230069 - 69
> > > url: www.road.de
> > >
> > > Amtsgericht Charlottenburg: HRB 96688 B
> > > Managing directors: Hans-Peter Constien, Hubertus von Streit
> >
> > Uli,
> > Do you have a link to the kernel list discussion?
> >
> kexec & 2 RAM banks [1]
>
> > At this point I am more
> > interested in getting cmdline support than in any particular
> > implementation. I did try your patch on top of mike's but I had no luck.
> >
> My Patch is a pure user space implementation and is supposed to work with
> a
> vanilla kernel.
>
> > One of the issues I have run into is the BROKEN Sharp bootloader that
> makes
> > things more interesting. Mike's patches can work around this problem by
> > setting up a fake ATAG list at a non-standard location.
> >
> The Idea for both approaches is to take the running kenel's ATAG list as a
> template for the new kernel's ATAG list. Mike Westerhof has this already
> implemented. I kind of stalled on that one as no one showed any interest.
> If
> you feel like testing such an approach, I could put the missing pieces
> together for you.
>
> > I would love to see more progress on this, since I would like to improve
> > support for booting devices from non-standard locations (ie SD card)
> > without custom kernels.
> >
> By the way, who is the original author of the arm-kexec-utils patch? I'd
> like
> to see kexec support pushed upstream which requires a sign-off of the
> original author.
>
> > Thank you for your help,
> >
> > Henry von Tresckow (hvontres)
>
> 1) kexec & 2 RAM banks
> http://marc.info/?l=linux-arm-kernel&m=118554158026945&w=4
>
>
> --
>
> ------- ROAD ...the handyPC Company - - -  ) ) )
>
> Uli Luckas
> Software Development
>
> ROAD GmbH
> Bennigsenstr. 14 | 12159 Berlin | Germany
> fon: +49 (30) 230069 - 64 | fax: +49 (30) 230069 - 69
> url: www.road.de
>
> Amtsgericht Charlottenburg: HRB 96688 B
> Managing directors: Hans-Peter Constien, Hubertus von Streit



IIRC, Richard Purdie wrote the original kexec patch for arm. I would love to
try out your solution. Do you know which version of the vanilla kernel now
has the proper patches in place? I would most likely need to do some
tweaking, since the original sharp bootloader passes a cmdline that is
incompatible with 2.6 kernels. But I would love to see some support for
kexec cmdline editing in the near future.

Henry von Tresckow (hvontres)