From: ebiederm@xmission.com (Eric W. Biederman)
To: Ingo Molnar <mingo@elte.hu>
Cc: "Willy Tarreau" <wtarreau@hera.kernel.org>,
"Dirk Hohndel" <hohndel@infradead.org>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
FBDEV-ML <linux-fbdev@vger.kernel.org>,
IDE-ML <linux-ide@vger.kernel.org>,
"Randy Dunlap" <rdunlap@xenotime.net>,
"James Bottomley" <James.Bottomley@suse.de>,
"H. Peter Anvin" <hpa@zytor.com>, X86-ML <x86@kernel.org>,
"Ahmed S. Darwish" <darwish.07@gmail.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Jeff Garzik" <jgarzik@pobox.com>,
"Vivek Goyal" <vgoyal@redhat.com>,
"Peter Zijlstra" <a.p.zijlstra@chello.nl>,
Dirk.Hohndel@intel.com, "Borislav Petkov" <bp@alien8.de>,
"Dave Jones" <davej@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Mark Lord" <kernel@teksavvy.com>,
"Arjan van de Ven" <arjan@infradead.org>,
"Tony Luck" <tony.luck@intel.com>,
KEXEC-ML <kexec@lists.infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
"Haren Myneni" <hbabu@us.ibm.com>, "Tejun Heo" <tj@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Willy Tarreau" <w@1wt.eu>
Subject: Re: [PATCH 0/2][concept RFC] x86: BIOS-save kernel log to disk upon panic
Date: Thu, 27 Jan 2011 07:47:54 -0800 [thread overview]
Message-ID: <m1aaimxs9h.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20110127114113.GB20279@elte.hu> (Ingo Molnar's message of "Thu, 27 Jan 2011 12:41:13 +0100")
Ingo Molnar <mingo@elte.hu> writes:
> * H. Peter Anvin <hpa@zytor.com> wrote:
>
>> On 01/26/2011 06:00 AM, Ingo Molnar wrote:
>> >
>> >I mean, use the warm reset vector to truly reset the box.
>> >
>> >Then, once a stable known-good kernel boots, *that* kernel can then recover all the
>> >log data which is sitting in a well-known place in RAM, automatically and
>> >transparently.
>> >
>> >Basically a bit like kexec, just more convenient and it also goes through the BIOS
>> >warm reset, so it might work better than kexec ...
>> >
>>
>> The problem is that the BIOS will often wipe memory.
>
> Yes - but at least a long time ago there used to be modi of reboot when the BIOS did
> not do this. Whether that's possible at all with modern BIOSen is a
> big question ...
As I recall that was how you went from 32bit mode to 16bit real mode.
The issue is that mode never reset the hardware it simply changed the
cpu mode.
Eric
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next prev parent reply other threads:[~2011-01-27 15:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110125134748.GA10051@laptop>
[not found] ` <AANLkTinU0KYiCd4p=z+=ojbkeEoT2G+CAYvdRU02KJEn@mail.gmail.com>
2011-01-26 12:49 ` [PATCH 0/2][concept RFC] x86: BIOS-save kernel log to disk upon panic Ahmed S. Darwish
2011-01-26 12:58 ` Ingo Molnar
2011-01-26 13:34 ` Ahmed S. Darwish
2011-01-26 14:00 ` Ingo Molnar
2011-01-27 4:35 ` H. Peter Anvin
2011-01-27 11:41 ` Ingo Molnar
2011-01-27 15:47 ` Eric W. Biederman [this message]
2011-01-27 16:12 ` H. Peter Anvin
2011-01-26 23:07 ` Luck, Tony
2011-01-26 23:16 ` Dave Jones
2011-01-26 23:21 ` Luck, Tony
2011-01-27 1:09 ` Ahmed S. Darwish
[not found] ` <20110127021338.GA20334@redhat.com>
2011-01-27 3:33 ` Ahmed S. Darwish
2011-01-27 4:44 ` H. Peter Anvin
2011-01-27 5:26 ` Ahmed S. Darwish
2011-01-27 7:51 ` Eric W. Biederman
2011-02-02 11:13 ` Ahmed S. Darwish
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