From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Wed, 07 Mar 2012 18:40:18 +0000 Subject: Re: [PATCH 2/3] Kbuild: Implement CONFIG_UIMAGE_KERNEL_NOLOAD Message-Id: <4F57AB92.6060907@wwwdotorg.org> List-Id: References: <1331080238-1524-1-git-send-email-swarren@wwwdotorg.org> <1331080238-1524-2-git-send-email-swarren@wwwdotorg.org> <20120307180815.GA27213@game.jcrosoft.org> In-Reply-To: <20120307180815.GA27213@game.jcrosoft.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jean-Christophe PLAGNIOL-VILLARD Cc: Michal Marek , linux-arch@vger.kernel.org, Michal Simek , Guan Xuetao , Mike Frysinger , nico@fluxnic.net, linux-sh@vger.kernel.org, microblaze-uclinux@itee.uq.edu.au, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Paul Mundt , uclinux-dist-devel@blackfin.uclinux.org, sparclinux@vger.kernel.org, Russell King , Haavard Skinnemoen , "David S. Miller" , linux-arm-kernel@lists.infradead.org, Hans-Christian Egtvedt On 03/07/2012 11:08 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 17:30 Tue 06 Mar , Stephen Warren wrote: >> This allows the user to use U-Boot's mkimage's -T kernel_noload option >> if their arch Kconfig allows it, and they desire. >> >> Signed-off-by: Stephen Warren >> --- >> The next patch enables this new CONFIG_ALLOW_ option for ARM. I assume >> that some other architectures will also be able to enable it, but I'm >> not familiar enough with any to know which. > I'm going to repeat. I don't think any impromevent here. > > with no specific kernel load address the uImage for is useless/ No, the whole point of this type of kernel image is that it doesn't need a specific load address; the kernel zImage can run from anywhere in RAM (provided AUTO_ZRELADDR is enabled, subject to some slight restrictions), and hence the uImage doesn't need to be loaded to or moved to any particular location. The scripts that U-Boot runs determine where the image gets loaded into memory. > And this no the job of the kernel to build a boot loader specific boot image > format. Not everyone agrees with this. > And the uImage format here is called the legacy format where now U-Boot > support a new format based on DT format. > > Will you plan to add it too? No. The last time I heard anyone talk about that, it sounded like the adoption was basically zero, so it seems pointless. Personally, I find creating that kind of image more complex, and don't see any benefits in that format either. > no sorry I don't think it's the right way to go. > > On X86 we boot zImage simply. The new uImage option to do not specify the load > address add nothing more than just boot a zImage for kernel point of view. U-Boot does not currently have the ability to boot zImage on ARM. > Further more on server the vendor will use grub mostly (even on ARM) and will > expect to boot a zImage. But that is irrelevant for the people who are using U-Boot not grub.