From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kuber.nabble.com (kuber.nabble.com [216.139.236.158]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id F203EDDE16 for ; Tue, 13 Nov 2007 18:35:46 +1100 (EST) Received: from isper.nabble.com ([192.168.236.156]) by kuber.nabble.com with esmtp (Exim 4.63) (envelope-from ) id 1IrqJD-0000GE-V3 for linuxppc-embedded@ozlabs.org; Mon, 12 Nov 2007 23:35:43 -0800 Message-ID: <13721038.post@talk.nabble.com> Date: Mon, 12 Nov 2007 23:35:43 -0800 (PST) From: Lorenz Kolb To: linuxppc-embedded@ozlabs.org Subject: Re: small bootloader that passes arguments In-Reply-To: <13712778.post@talk.nabble.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii References: <13712778.post@talk.nabble.com> List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, the normal operation of a bootloader is: memcpy() -- copy the programme to boot to some new location maybe some decoding done here, too jump_to_addr() -- the easiest way to jump to some address in a higher level language is to make a function call to some pointer. You can pass arguments to this function, that is what bootloaders like u-boot do. Personally I would recommand you to use some small first-stage-loader loading U-Boot and make U-Boot do the rest. There is a U-Boot 1.1.4 port on Xilinx' website for some Xilinx boards that can easily be adapted to Your board (if it is no yet supported), I guess. You can find Xilinx' U-Boot-"tree" here: http://www.xilinx.com/ml410-p/81i_19.5/designs/u-boot.zip Regards, Lorenz Kolb khollan wrote: > > Hi, > > I would like to create a small bootloader that is able to pass kernel > arguments and boot a linux kernel. Im using a xilinx PPC, and have > already booted a working kernel with a Xilinx provided XMD bootloader over > USB. My main question is how does a bootloader pass these arguments to > the kernel before booting it? Most specifically the root=/dev/xsa1 > command so I can tell it to either boot from compact flash or NFS. > > I really don't want to try and port U-boot since I don't need the bells > and whistles and I want it to fit in the BRAM of the FPGA so it will load > when I load the hardware configuration. > -- View this message in context: http://www.nabble.com/small-bootloader-that-passes-arguments-tf4793411.html#a13721038 Sent from the linuxppc-embedded mailing list archive at Nabble.com.