From owner-freebsd-hackers@FreeBSD.ORG  Sun Jan 23 20:03:11 2011
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 0360B106564A
	for <hackers@freebsd.org>; Sun, 23 Jan 2011 20:03:11 +0000 (UTC)
	(envelope-from timon@timon.net.nz)
Received: from frost.plasmahost.ru (plasmahost.ru [178.63.60.242])
	by mx1.freebsd.org (Postfix) with ESMTP id A45DD8FC0A
	for <hackers@freebsd.org>; Sun, 23 Jan 2011 20:03:10 +0000 (UTC)
Received: from [192.168.1.50] ([85.21.143.38])
	(AUTH: PLAIN timon@timon.net.nz, SSL: TLSv1/SSLv3, 256bits,
	CAMELLIA256-SHA)
	by frost.plasmahost.ru with esmtp; Sun, 23 Jan 2011 20:02:31 +0000
	id 00017C63.000000004D3C8959.000012EE
Message-ID: <4D3C8976.5060109@timon.net.nz>
Date: Sun, 23 Jan 2011 23:03:02 +0300
From: Alexandr Matveev <timon@timon.net.nz>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US;
	rv:1.9.2.13) Gecko/20110101 Thunderbird/3.1.7
MIME-Version: 1.0
To: Neel Natu <neelnatu@gmail.com>
References: <4D3C4F94.7020307@timon.net.nz>
	<AANLkTik+zwsh8CCcWkoRHcUZ=BN85BffxcotCbxMBDwH@mail.gmail.com>
In-Reply-To: <AANLkTik+zwsh8CCcWkoRHcUZ=BN85BffxcotCbxMBDwH@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Content-Filtered-By: Mailman/MimeDel 2.1.5
Cc: hackers@freebsd.org
Subject: Re: How to read non-physical memory?
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 23 Jan 2011 20:03:11 -0000

On 23.01.2011 22:26, Neel Natu wrote:
> Hi Alexandr,
>
> On Sun, Jan 23, 2011 at 7:56 AM, Alexandr Matveev<timon@timon.net.nz>  wrote:
>> Hello.
>>
>>   When FreeBSD boots with 'boot -v' it show SMAP:
>> SMAP type=01 base=0000000000000000 len=000000000009d800
>> SMAP type=02 base=000000000009d800 len=0000000000002800
>> SMAP type=02 base=00000000000e0000 len=0000000000020000
>> SMAP type=01 base=0000000000100000 len=00000000bfdb0000
>> <...>
>> SMAP type=02 base=00000000fed1c000 len=0000000000004000
>> <...>
>>
>>   Memory range 0xfed1c000 - 0xfed2000 belongs to ICH8 mapped to memory
>> configuration registers.
>>   If I correctly understand mem man page, /dev/mem allow to read only real
>> physical memory. How can I read data from this range?
> I am not sure what the man page says but you can certainly use
> /dev/mem to access mmio space.
>
> I have used 'dd' with 'if=/dev/mem' to dump out mmio registers on
> amd64. YMMV with other architectures.

   Thank you very much.
   dd if=/dev/mem of=mem.dump bs=4 count=4095 skip=1068789760
   works perfectly!

-- 
Alexandr Matveev