From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx.dlasys.net (24.152.213.223.res-cmts.eph.ptd.net [24.152.213.223]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 3ECBFDDE34 for ; Thu, 21 Dec 2006 17:01:58 +1100 (EST) Message-ID: <458A2289.4070401@dlasys.net> Date: Thu, 21 Dec 2006 00:58:33 -0500 From: "David H. Lynch Jr." MIME-Version: 1.0 To: Clint Thomas Subject: Re: Define Linux system memory References: <3C02138692C13C4BB675FE7EA2409529261209@bluefin.Soneticom.local> In-Reply-To: <3C02138692C13C4BB675FE7EA2409529261209@bluefin.Soneticom.local> Content-Type: multipart/alternative; boundary="------------010900000301060409060905" Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is a multi-part message in MIME format. --------------010900000301060409060905 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Clint Thomas wrote: > To anybody who has done this before or understands how to do this, I > was wondering if you know how to "*tell*" the kernel how much memory > there is in the system. An example would be if I have 512MB of RAM, > but only want the system to know that there is about 500MB in RAM, so > that 12MB does not exist to the OS/kernel. Would this require mucking > about in U-boot? or can I just define this in the kernel source? Thanks > > Clinton Thomas Most bootloaders including u-boot pass a board information structure that includes a variety of information including the memory size. Also I think top of memory is also typically passed to the Linux Kernel as a register parameter by the boot loader. > > ------------------------------------------------------------------------ > > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded -- Dave Lynch DLA Systems Software Development: Embedded Linux 717.627.3770 dhlii@dlasys.net http://www.dlasys.net fax: 1.253.369.9244 Cell: 1.717.587.7774 Over 25 years' experience in platforms, languages, and technologies too numerous to list. "Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction." Albert Einstein --------------010900000301060409060905 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Clint Thomas wrote:
To anybody who has done this before or understands how to do this, I was wondering if you know how to "tell" the kernel how much memory there is in the system. An example would be if I have 512MB of RAM, but only want the system to know that there is about 500MB in RAM, so that 12MB does not exist to the OS/kernel. Would this require mucking about in U-boot? or can I just define this in the kernel source? Thanks
 
 Clinton Thomas

    Most bootloaders including u-boot pass a board information structure that includes a variety of information including the memory size.
    Also I think top of memory is also typically passed to the Linux Kernel as a register parameter  by the boot loader.



 

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-- 
Dave Lynch 					  	    DLA Systems
Software Development:  				         Embedded Linux
717.627.3770 	       dhlii@dlasys.net 	  http://www.dlasys.net
fax: 1.253.369.9244 			           Cell: 1.717.587.7774
Over 25 years' experience in platforms, languages, and technologies too numerous to list.

"Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction."
Albert Einstein
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