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). Will