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From: "H. Peter Anvin" <hpa@zytor.com>
To: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	Jeremy Fitzhardinge <jeremy@goop.org>,
	Rusty Russell <rusty@rustcorp.com.au>,
	maluta_tiago@yahoo.com.br, lguest@ozlabs.org,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [Lguest] lguest: unhandled trap
Date: Mon, 20 Oct 2008 12:01:25 -0700	[thread overview]
Message-ID: <48FCD585.4050107@zytor.com> (raw)
In-Reply-To: <1224494055.9053.192.camel@zakaz.uk.xensource.com>

Ian Campbell wrote:
> 
> Wasn't there some concern about BIOSes which don't correctly reserve
> their DMI tables? Or don't even have e820 maps? H. Peter once said:
> 
>> It's pretty standard for 0xf0000...0x100000 to be marked RESERVED in
>> E820 on real hardware (including the system I'm typing on right now.)
>> It is so marked to indicate that hardware cannot be mapped into that
>> space.  However, you can't rely on this fact -- heck, you can't rely on
>> E820 even existing on a real machine.  I have specimens of real-life
>> machines that go both ways.
> 

Not only that, but the ACPI spec states explicitly that the ISA magic 
areas should be handled without relying on E820.

	-hpa

  parent reply	other threads:[~2008-10-20 19:06 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <713731.28571.qm@web50701.mail.re2.yahoo.com>
     [not found] ` <200810201452.04932.rusty@rustcorp.com.au>
2008-10-20  7:22   ` [Lguest] lguest: unhandled trap Ingo Molnar
2008-10-20  7:43     ` Jeremy Fitzhardinge
2008-10-20  7:53       ` Ingo Molnar
2008-10-20  9:14         ` Ian Campbell
2008-10-20  9:27           ` Ingo Molnar
2008-10-20 19:01           ` H. Peter Anvin [this message]
2008-10-20 22:48     ` Rusty Russell
2008-10-20 23:22       ` Ingo Molnar
     [not found] <559519.75404.qm@web50707.mail.re2.yahoo.com>
2008-10-19 23:39 ` Rusty Russell
2008-10-20  4:15   ` Jeremy Fitzhardinge

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