From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 15 Mar 2007 13:52:06 +0000 (GMT) Received: from phoenix.bawue.net ([193.7.176.60]:46527 "EHLO mail.bawue.net") by ftp.linux-mips.org with ESMTP id S20022327AbXCONwA (ORCPT ); Thu, 15 Mar 2007 13:52:00 +0000 Received: from lagash (intrt.mips-uk.com [194.74.144.130]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.bawue.net (Postfix) with ESMTP id 94F4C85A3C; Thu, 15 Mar 2007 14:42:54 +0100 (CET) Received: from ths by lagash with local (Exim 4.63) (envelope-from ) id 1HRqEU-0008Q0-83; Thu, 15 Mar 2007 13:43:06 +0000 Date: Thu, 15 Mar 2007 13:43:06 +0000 To: Rajat Jain Cc: linux-mips@linux-mips.org Subject: Re: How does boot loader pass initrd address / size to kernel? Message-ID: <20070315134306.GB25863@networkno.de> References: <20070315133950.GA25863@networkno.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070315133950.GA25863@networkno.de> User-Agent: Mutt/1.5.13 (2006-08-11) From: Thiemo Seufer Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 14481 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ths@networkno.de Precedence: bulk X-list: linux-mips Thiemo Seufer wrote: > Rajat Jain wrote: > > Hi, > > > > I'm running an ancient Linux kernel 2.4.20 (please don't ask me why > > :-( ) on a MIPS 4KEC. I am experimenting with initrd and my initrd > > fails to mount. My bootloader (U-BOOT) coorectly loads the initrd into > > RAM as I can see. > > > > I am wondering how does the kernel get to know the address at which > > the initrd is loaded by boot loader? How does the boot loader > > communicate this to the kernel? > > > > I can see that when emebedding root filesystem into kernel image, the > > symbols __rd_start and __rd_end are defined by the linker script and > > hence the kernel gets to know. However, how does this happen when > > bootloader loads the ramdisk and needs to tell the kernel? > > http://www.linux-mips.org/wiki/Kernel_Command_Line_Arguments mentions > rd_start and rd_size which are used for this purpose. ... and they IIRC didn't exist in 2.4.20, but e.g. Debian's 2.4 mips kernels carry a patch to add such support. Thiemo