From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: [PATCH 2/3] Kbuild: Implement CONFIG_UIMAGE_KERNEL_NOLOAD Date: Wed, 07 Mar 2012 16:03:04 -0500 (EST) Message-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> <4F57AB92.6060907@wwwdotorg.org> <20120307183633.GB27213@game.jcrosoft.org> <4F57C4C6.2070602@wwwdotorg.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: In-reply-to: <4F57C4C6.2070602@wwwdotorg.org> Sender: linux-kbuild-owner@vger.kernel.org To: Stephen Warren Cc: Jean-Christophe PLAGNIOL-VILLARD , Michal Marek , linux-arch@vger.kernel.org, Michal Simek , Guan Xuetao , Mike Frysinger , 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 List-Id: linux-arch.vger.kernel.org On Wed, 7 Mar 2012, Stephen Warren wrote: > On 03/07/2012 11:36 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > > On 11:40 Wed 07 Mar , Stephen Warren wrote: > >> 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. > > > > so instead of spending time on the uImage add simply the support the zImage to > > U-Boot as this AUTO_ZRELADDR have 0 advantage compare to the zImage > > Thinking more about this, I guess the reliance on AUTO_ZRELADDR is wrong > here; Russell, Nico, is the ARM decompressor fully position-independent > irrespective of the AUTO_ZRELADDR setting. Absolutely. > That setting just determines where the decompressor writes its output, > not what address the decompressor can run at, right? Right. > So, this KERNEL_NOLOAD feature could be > enabled in all cases on ARM, not only when AUTO_ZRELADDR is enabled. Except when CONFIG_ZBOOT_ROM is selected (if the uImage format allows it), or when the u-Boot environment doesn't know where to load the uImage. FWIW, I really hate this confusing usage of "noload" imposed on us by we know who. I thought better than contesting his definition though. But yes, AUTO_ZRELADDR has no effect on the location where the zImage should be _loaded_, except for the 128MB restriction. > As such to address Jean-Christophe's most recent comment above, this > patch isn't about adding support for AUTO_ZRELADDR, but for U-Boot's > kernel_noload feature, so comparisons should be drawn between > kernel_noload uImages and zImage, not between AUTO_ZRELADDR and zImage. > > In other words: > > We already have and need ZRELADDR no matter what, for reasons unrelated > to U-Boot/uImage. Well, I do have a patch series getting rid of ZRELADDR entirely, and AUTO_ZRELADDR would then become implicit, unless CONFIG_PHYS_OFFSET is defined. Nicolas From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relais.videotron.ca ([24.201.245.36]:23997 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751812Ab2CGVDF (ORCPT ); Wed, 7 Mar 2012 16:03:05 -0500 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN; CHARSET=US-ASCII Date: Wed, 07 Mar 2012 16:03:04 -0500 (EST) From: Nicolas Pitre Subject: Re: [PATCH 2/3] Kbuild: Implement CONFIG_UIMAGE_KERNEL_NOLOAD In-reply-to: <4F57C4C6.2070602@wwwdotorg.org> Message-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> <4F57AB92.6060907@wwwdotorg.org> <20120307183633.GB27213@game.jcrosoft.org> <4F57C4C6.2070602@wwwdotorg.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Stephen Warren Cc: Jean-Christophe PLAGNIOL-VILLARD , Michal Marek , linux-arch@vger.kernel.org, Michal Simek , Guan Xuetao , Mike Frysinger , 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 Message-ID: <20120307210304.Rt0NmN6bOUhuzGChDelq6ZFRp5JWv0TD2ry6eOLKYuU@z> On Wed, 7 Mar 2012, Stephen Warren wrote: > On 03/07/2012 11:36 AM, Jean-Christophe PLAGNIOL-VILLARD wrote: > > On 11:40 Wed 07 Mar , Stephen Warren wrote: > >> 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. > > > > so instead of spending time on the uImage add simply the support the zImage to > > U-Boot as this AUTO_ZRELADDR have 0 advantage compare to the zImage > > Thinking more about this, I guess the reliance on AUTO_ZRELADDR is wrong > here; Russell, Nico, is the ARM decompressor fully position-independent > irrespective of the AUTO_ZRELADDR setting. Absolutely. > That setting just determines where the decompressor writes its output, > not what address the decompressor can run at, right? Right. > So, this KERNEL_NOLOAD feature could be > enabled in all cases on ARM, not only when AUTO_ZRELADDR is enabled. Except when CONFIG_ZBOOT_ROM is selected (if the uImage format allows it), or when the u-Boot environment doesn't know where to load the uImage. FWIW, I really hate this confusing usage of "noload" imposed on us by we know who. I thought better than contesting his definition though. But yes, AUTO_ZRELADDR has no effect on the location where the zImage should be _loaded_, except for the 128MB restriction. > As such to address Jean-Christophe's most recent comment above, this > patch isn't about adding support for AUTO_ZRELADDR, but for U-Boot's > kernel_noload feature, so comparisons should be drawn between > kernel_noload uImages and zImage, not between AUTO_ZRELADDR and zImage. > > In other words: > > We already have and need ZRELADDR no matter what, for reasons unrelated > to U-Boot/uImage. Well, I do have a patch series getting rid of ZRELADDR entirely, and AUTO_ZRELADDR would then become implicit, unless CONFIG_PHYS_OFFSET is defined. Nicolas