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Date: Mon, 02 Aug 2004 11:49:02 -0700
From: "Martin J. Bligh" <mbligh@aracnet.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
cc: jmoyer@redhat.com, Arjan van de Ven <arjanv@redhat.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: finding out the boot cpu number from userspace
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>> Eric went to some lengths to migrate us back to the original boot CPU 
>> before kexec'ing. I think this is unnecessary - the new kernel should
>> handle booting on any CPU just fine (there was a panic in there at one
>> point if the boot CPU didn't match the BIOS's spec'ed one, but I removed
>> it).
> 
> Several systems have broken SMM or BIOS functionality that requires the
> *real* boot processor is used. The panic was correct and should be
> restored. See apm_power_off() for one example.

Ah, OK didn't know that ... however, I'm not convinced that panicing is 
really that useful ... what happens if you proceed? IIRC, this is before 
console_init as well, so people won't even see the error. At least it 
should only do that on machines that are borked in such a fashion - 99% of 
machines will work fine, AFAICS.

M.