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Date: Fri, 28 Aug 2009 21:35:23 +0200
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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To: "wilbur.chan" <wilbur512@gmail.com>
Subject: Re: [PATCH 1/2] powerpc: add kexec support on FSL-Book-E
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wilbur.chan wrote:
> Hi  Sebastian,
Hi Wilbur,

> Recently I've implemented  non-SMP kexec on MPC8572 and P2020ds(2G ram).
> 
> 
> 
> I modified your
> 
> misc_32.S that , I setuped  two '1G' entries  after the "rfi"
> instruction, so that I did
> not  need to setup  mapping for instruction address.
If you send some patches I could add them to my tree so we have
everything together.

> As for SMP supporting,I tried to close one of the CPUs in
> default_machine_kexec,
> 
> and found that , when cpu1  closed  ,and if the second kernel is NON-
> 
> SMP,everything went well.so I added some code in
> 
> kexec-tools, to make sure the 'kexec' process was running on CPU 0.
I remember that ppc64 had some code to suspend and start the second CPU in
the purgatory code. Not sure if there is a generic way for this on ppc32
or it is a book-e thing. Haven't look at it (yet).

> So, there left one problem, I can not start the second SMP-kernel,
> even if I  closed
> 
> CPU1.  Any suggestions?
The interesting thing is where do you hang/crash. It could be possible
that the kernel is waiting for the non-boot cpus to show up and it
doesn't. Have you look how u-boot prepares the cpus and how kernel
disables them on shutdown?


> PTW:
> 
> no-smp ---> no-smp.........OK
> no-smp --->smp...............OK
Does this mean your smp kernel has more that one CPU or just one?

> smp(with cpu1 closed)---->no-smp..............OK
> smpw(with cpu1 closed)---->smp ................FAILED
> 
> 
> regards,
> 
> wilbur

Sebastian