Re: [PATCH -mm] kexec jump -v9

[Vivek Goyal <vgoyal@redhat.com>]

On Wed, May 14, 2008 at 12:03:29PM -0400, Vivek Goyal wrote:
> On Thu, Mar 06, 2008 at 11:13:08AM +0800, Huang, Ying wrote:
> > This is a minimal patch with only the essential features. All
> > additional features are split out and can be discussed later. I think
> > it may be easier to get consensus on this minimal patch.
> > 
> 
> Hi Huang,
> 
> Ok, after a long time, I am back to testing and reviewing this patch.
> 
> 
> [..]
> > 7. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as
> >    root file system.
> > 
> > 8. In kernel C, load the memory image of kernel A as follow:
> > 
> >    /sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf
> > 
> 
> How do I got back to original kernel without loading dump.elf. I mean,
> original kernel is already in memory and I don't have to first save
> it to disk and then reload back. Is there a way to do it? If not, then
> we need to modify kexec-tools to support that.
> 
> Something like
> 
> kexec --entry=<entry point>, should tell kexec that kernel is already
> loaded. Just do the bit to set the entry point properly.
> 

Never mind. I found it. Following worked for me for returning back to
original kernel.

kexec --load-jump-back-helper --entry=<entry point>

Just wondering if "--load-jump-back-helper" should be an explicit option
or kexec should silently assume it if no "-l" or "-p" is given.

Thanks
Vivek