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Date: Thu, 25 Oct 2007 10:08:16 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Andi Kleen <ak@novell.com>
CC: "Eric W. Biederman" <ebiederm@xmission.com>,
       Thomas Gleixner <tglx@linutronix.de>,
       "Huang, Ying" <ying.huang@intel.com>,
       Andrew Morton <akpm@linux-foundation.org>,
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       Chandramouli Narayanan <mouli@linux.intel.com>,
       LKML <linux-kernel@vger.kernel.org>,
       Arjan van de Ven <arjan@infradead.org>
Subject: Re: [PATCH 1/3 -v4] x86_64 EFI runtime service support: EFI basic
 runtime service support
References: <1193295473.23935.202.camel@caritas-dev.intel.com> <alpine.LFD.0.9999.0710251800250.3186@localhost.localdomain> <m1r6jj5e27.fsf@ebiederm.dsl.xmission.com> <200710251906.10210.ak@novell.com>
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Andi Kleen wrote:
>> Especially for accessing the real time clock that has a well
>> defined hardware interface going through efi an additional
>> software emulation layer looks like asking for trouble.
> 
> I agree it's pointless for the hardware clock, but EFI 
> also offers services to write some data to the CMOS RAM
> which could be very useful to save oops data over reboot.
> I don't think this can be done safely otherwise 
> without BIOS cooperation.
> 

The ability to scurry away even a small amount of data without relying 
on the disk system is highly desirable.  Think next-boot type information.

	-hpa