From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from web36606.mail.mud.yahoo.com (web36606.mail.mud.yahoo.com [209.191.85.23]) by ozlabs.org (Postfix) with SMTP id 0A165DDEC5 for ; Thu, 21 Dec 2006 18:05:32 +1100 (EST) Date: Wed, 20 Dec 2006 23:05:28 -0800 (PST) From: Parav Pandit Subject: Re: Define Linux system memory To: "David H. Lynch Jr." , Clint Thomas In-Reply-To: <458A2289.4070401@dlasys.net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-228382367-1166684728=:74305" Message-ID: <588266.74305.qm@web36606.mail.mud.yahoo.com> Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --0-228382367-1166684728=:74305 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Hi, This memory information is passed by the u-boot in bd_info structure (typedef to bd_t). Its defined in include/asm-ppc/ppcboot.h file. First two parameters specify the start address and length. Well, I'll at least try on my host x86 system. There is doesn't get from the grub. It should work and I should be able to see in cat /proc/meminfo. I'll try and let you know. Regards, Parav Pandit "David H. Lynch Jr." wrote: 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 _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com --0-228382367-1166684728=:74305 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit

Hi,

This memory information is passed by the u-boot in bd_info structure (typedef to bd_t).

Its defined in include/asm-ppc/ppcboot.h file.

First two parameters specify the start address and length.

Well, I'll at least try on my host x86 system. There is doesn't get from the grub.

It should work and I should be able to see in cat /proc/meminfo.

I'll try and let you know.

Regards,

Parav Pandit

"David H. Lynch Jr." <dhlii@dlasys.net> wrote:

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  
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