From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from avon.wwwdotorg.org ([70.85.31.133]:45912 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753935Ab3CRSOv (ORCPT ); Mon, 18 Mar 2013 14:14:51 -0400 Message-ID: <51475997.2060008@wwwdotorg.org> Date: Mon, 18 Mar 2013 12:14:47 -0600 From: Stephen Warren MIME-Version: 1.0 Subject: Re: [U-Boot] [RFC] Kbuild support for ARM FIT images References: <20130222160044.GA16357@quad.lixom.net> <20130318163648.GA3722@amd.pavel.ucw.cz> <20130318164426.GI30923@n2100.arm.linux.org.uk> <20130318174931.GB4230@amd.pavel.ucw.cz> <20130318175746.GJ30923@n2100.arm.linux.org.uk> <20130318180458.GC4230@amd.pavel.ucw.cz> In-Reply-To: <20130318180458.GC4230@amd.pavel.ucw.cz> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Pavel Machek Cc: Russell King - ARM Linux , "Fernandes, Joel A" , Grant Likely , linux-kbuild@vger.kernel.org, tony@atomide.com, "Rini, Tom" , Grant Likely , u-boot@lists.denx.de, Linux OMAP List , Linux ARM Kernel List On 03/18/2013 12:04 PM, Pavel Machek wrote: > On Mon 2013-03-18 17:57:46, Russell King - ARM Linux wrote: >> On Mon, Mar 18, 2013 at 06:49:32PM +0100, Pavel Machek wrote: >>> What I wanted to say is that kernel build traditionaly produced >>> something useful, something bootloader can actually boot. Currently, >>> make uImage produces u-boot image. Please keep that capability. >> >> Unfortunately, there is a fundamental problem with uImage. It encodes >> the load address, and that is utterly incompatible with the goal of >> having a kernel image which boots on multiple platforms. >> >> uImage isn't going anywhere for the time being, but you will find >> that: >> >> a) recent kernels will just wrap the zImage without a DTB, so >> appended DTBs can't be used with it >> b) it won't work with MULTIPLATFORM-enabled kernels, unless you >> provide make with a LOADADDR= argument to tell it where the >> uImage is to be loaded - which is platform specific. >> >> (b) fundamentally can't be solved in kbuild. If you want to use >> uImage with multiple platforms from the same zImage, then you need >> to generate multiple uImage files with different load addresses. >> That's purely - and solely - down to the dysfunctional uImage format. > > I know. uImage is not perfect. But solution should be "adopt a better > format" (ARM FIT?), not "drop support for making useful images > altogether" as Olof proposed before. Raw zImage /is/ the useful format that should be adopted.