Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 24 Sep 2002 16:47:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 24 Sep 2002 16:47:10 -0400 Received: from albatross.mail.pas.earthlink.net ([207.217.120.120]:45244 "EHLO albatross.prod.itd.earthlink.net") by vger.kernel.org with ESMTP id ; Tue, 24 Sep 2002 16:45:59 -0400 Message-ID: <3D91413C.1050603@goingware.com> Date: Wed, 25 Sep 2002 00:53:16 -0400 From: "Michael D. Crawford" Organization: GoingWare Inc. - Expert Software Development and Consulting User-Agent: Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.0.0) Gecko/20020622 Debian/1.0.0-0.woody.1 X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Conserving memory for an embedded application Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1824 Lines: 41 I am helping my client design an embedded hardware device that we may run Linux on. An important concern is to minimize the amount of ROM and flash ram that the device has, both to save manufacturing cost and to minimize power consumption. One question I have is whether it is possible to burn an uncompressed image of the kernel into flash, and then boot the kernel in-place, so that it is not copied to RAM when it runs. Of course the kernel would need RAM for its data structures and user programs, but it would seem to me I should be able to run the kernel without making a RAM copy. It would be OK if I had to mess with the bootloader to do this. It would also be helpful if a filesystem image containing a user program could be burned into flash, and then the program run directly out of flash. Some amount of RAM would be saved if the executing code were run from the flash ROM rather than being copied into RAM as would normally be the case when executing a demand-paged executable. This last is probably not as important as running the kernel out of flash as I don't think the user program would be very large. Also, what is the minimum amount of physical ram that you think I can get any version of the kernel later than 2.0 or so to run in? I heard somewhere that someone can boot an x86 system with as little as 2MB of RAM. Is that the case? Thank you, Mike -- Michael D. Crawford GoingWare Inc. - Expert Software Development and Consulting http://www.goingware.com/ crawford@goingware.com Tilting at Windmills for a Better Tomorrow. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/