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 for kexec@lists.infradead.org; Fri, 11 Oct 2013 16:40:22 +0000
Date: Fri, 11 Oct 2013 17:39:33 +0100
From: Matthew Garrett <mjg59@srcf.ucam.org>
Subject: Re: kexec: Clearing registers just before jumping into purgatory
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To: Richard Weinberger <richard.weinberger@gmail.com>
Cc: keir@xen.org, Kees Cook <keescook@chromium.org>, Daniel Kiper <daniel.kiper@oracle.com>, kexec@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>, xen-devel@lists.xen.org, hbabu@us.ibm.com, "Eric W. Biederman" <ebiederm@xmission.com>, jbeulich@suse.com, "H. Peter Anvin" <hpa@linux.intel.com>, Vivek Goyal <vgoyal@redhat.com>, david.vrabel@citrix.com

On Fri, Oct 11, 2013 at 06:33:23PM +0200, Richard Weinberger wrote:
> On Fri, Oct 11, 2013 at 5:48 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> > On Fri, Oct 11, 2013 at 11:44:50AM -0400, Vivek Goyal wrote:
> >
> >> Just Curious. How is it useful. IOW, what's your use case of booting a new
> >> kernel and then jumping back.
> >
> > I'm kexecing into a kernel with a modified /dev/mem, modifying the
> > original kernel and then jumping back into it.
> 
> How do you update the original kernel?

It's still in RAM, so the same way you'd modify any other arbitrary 
physical address?

-- 
Matthew Garrett | mjg59@srcf.ucam.org

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