Possible regression in kexec on ARM ARMv6 and ARMv7 cores

Simon Horman horms at verge.net.au
Fri Oct 21 22:20:16 EDT 2011


On Fri, Oct 21, 2011 at 10:15:24AM +0100, Will Deacon wrote:
> On Fri, Oct 21, 2011 at 09:59:58AM +0100, Simon Horman wrote:
> > On Fri, Oct 21, 2011 at 09:46:41AM +0100, Will Deacon wrote:
> > > The more difficult case is when you want to offline the secondary CPUs into
> > > a pen and then boot them in the new kernel. I did get some of this working,
> > > but there are outstanding issues with whether the pen should be at a fixed
> > > location or not. If not, then we need a way to tell the new kernel where it
> > > is, which may involve updating the DT blob...
> > 
> > Is the implication that the (working) callback method does not
> > give the second kernel any secondary CPUs?
> 
> What the callback does it up to you. You just need to make sure that you can
> cope with the kernel disappearing later on, so you'll probably need some
> hardware mechanism for offlining a CPU (for example, placing it in SRAM
> or cutting the power).

Thanks, it seems that I now have a bit of work to do implementing
a callback.



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