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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Nameer Yarkon <nameer.yarkon@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Reading /dev/mem by dd
Date: Tue, 16 Feb 2010 12:31:41 +0000	[thread overview]
Message-ID: <20100216123141.6c601dfd@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <bec9a5871002160035v63cce8ck9ecb9252b2f162a6@mail.gmail.com>

> how does X11 get now direct access to the physical memory (instead of
> /dev/mem) ?

Via frame buffer devices.

If you think about things like hot-plug it's rather hard to do frame
buffer access any other way. The rules on memory types and aliasing also
make it nearly impossible to do properly with /dev/mem on a modern CPU.

Alan

  parent reply	other threads:[~2010-02-16 12:32 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-16  8:35 Nameer Yarkon
2010-02-16  8:41 ` Andi Kleen
2010-02-16  9:03   ` Nameer Yarkon
2010-02-16 12:31 ` Alan Cox [this message]
  -- strict thread matches above, loose matches on Subject: below --
2009-11-11 14:36 Anton D. Kachalov
2009-11-11 16:20 ` Américo Wang
2009-11-12 15:46   ` Anton D. Kachalov
2009-11-11 21:09 ` Robert Hancock
2009-11-12  2:12   ` Henrique de Moraes Holschuh
2009-11-12 11:09     ` Alan Cox
2009-11-12 16:06       ` Henrique de Moraes Holschuh
2009-11-12 17:52         ` Alan Cox
2009-11-12 16:44     ` Andi Kleen
2009-11-12 17:37       ` Henrique de Moraes Holschuh
2009-11-12 17:49         ` Alan Cox
2009-11-12 17:57           ` Henrique de Moraes Holschuh
2009-11-12 18:13             ` Alan Cox
2009-11-12 20:02               ` Henrique de Moraes Holschuh
2009-11-12 20:06                 ` Alan Cox
2009-11-12 21:07         ` Krzysztof Halasa
2009-11-12 21:29           ` Cyrill Gorcunov

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