From: Rob Herring <robh@kernel.org> To: Tero Kristo <t-kristo@ti.com> Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, trini@konsulko.com, Tony Lindgren <tony@atomide.com>, Russell King - ARM Linux <linux@armlinux.org.uk>, frowand.list@gmail.com, wmills@ti.com, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Subject: Re: [RFC 12/13] ARM: dts: ti: add dra71-evm FIT description file Date: Tue, 22 May 2018 15:01:00 -0500 [thread overview] Message-ID: <20180522200100.GA23937@rob-hp-laptop> (raw) In-Reply-To: <43ff3894-a287-1558-687c-40f50712735c@ti.com> On Mon, May 21, 2018 at 09:57:54AM +0300, Tero Kristo wrote: > On 17/04/18 17:49, Tony Lindgren wrote: > > * Tero Kristo <t-kristo@ti.com> [180417 09:36]: > > > In typical setup, you can boot a large number of different configs via: > > > > > > bootm 0x82000000#dra71-evm#nand#lcd-auo-g101evn01.0 > > > > > > ... assuming the configs were named like that, and assuming they would be > > > compatible with each other. The am57xx-evm example provided is better, as > > > you can chain the different cameras to the available evm configs. > > > > Why not just do it in the bootloader to put together the dtb? > > > > Then for external devices, you could just pass info on the > > kernel cmdline with lcd=foo camera=bar if they cannot be > > detected over I2C. > > (Added Linux ARM list to CC, this was not part of the original delivery.) > > Ok trying to resurrect this thread a bit. Is there any kind of consensus how > things like this should be handled? Should we add the DT overlay files to > kernel tree or not? IMO, yes. > Should we add any kind of build infra to kernel tree, and at what level > would this be? Just DT overlay file building support, and drop the FIT build > support as was proposed in this RFC series or...? I think I mentioned this already, but I expect that this is going to cause a number of conversions of dtsi + dtsi -> dtb into base dts and overlay(s) dts files. In doing so, we still need to be able to build the original, full dtb. > U-boot can obviously parse the base DTB + overlay DTB:s into a single DTB, > but this is somewhat clumsy approach and is relatively error prone to get it > right. Why? How is the kernel better? > Building the FIT image post kernel build would also be possible, but who > would be doing this, is there any need to get this done in generic manner or > shall we just add SoC vendor specific tools for this? I'll tell you up front, I'm not a fan of FIT image (nor uImage, Android boot image, $bootloader image). If you want a collection of files and some configuration data, use a filesystem and a text file. Rob
WARNING: multiple messages have this Message-ID (diff)
From: robh@kernel.org (Rob Herring) To: linux-arm-kernel@lists.infradead.org Subject: [RFC 12/13] ARM: dts: ti: add dra71-evm FIT description file Date: Tue, 22 May 2018 15:01:00 -0500 [thread overview] Message-ID: <20180522200100.GA23937@rob-hp-laptop> (raw) In-Reply-To: <43ff3894-a287-1558-687c-40f50712735c@ti.com> On Mon, May 21, 2018 at 09:57:54AM +0300, Tero Kristo wrote: > On 17/04/18 17:49, Tony Lindgren wrote: > > * Tero Kristo <t-kristo@ti.com> [180417 09:36]: > > > In typical setup, you can boot a large number of different configs via: > > > > > > bootm 0x82000000#dra71-evm#nand#lcd-auo-g101evn01.0 > > > > > > ... assuming the configs were named like that, and assuming they would be > > > compatible with each other. The am57xx-evm example provided is better, as > > > you can chain the different cameras to the available evm configs. > > > > Why not just do it in the bootloader to put together the dtb? > > > > Then for external devices, you could just pass info on the > > kernel cmdline with lcd=foo camera=bar if they cannot be > > detected over I2C. > > (Added Linux ARM list to CC, this was not part of the original delivery.) > > Ok trying to resurrect this thread a bit. Is there any kind of consensus how > things like this should be handled? Should we add the DT overlay files to > kernel tree or not? IMO, yes. > Should we add any kind of build infra to kernel tree, and at what level > would this be? Just DT overlay file building support, and drop the FIT build > support as was proposed in this RFC series or...? I think I mentioned this already, but I expect that this is going to cause a number of conversions of dtsi + dtsi -> dtb into base dts and overlay(s) dts files. In doing so, we still need to be able to build the original, full dtb. > U-boot can obviously parse the base DTB + overlay DTB:s into a single DTB, > but this is somewhat clumsy approach and is relatively error prone to get it > right. Why? How is the kernel better? > Building the FIT image post kernel build would also be possible, but who > would be doing this, is there any need to get this done in generic manner or > shall we just add SoC vendor specific tools for this? I'll tell you up front, I'm not a fan of FIT image (nor uImage, Android boot image, $bootloader image). If you want a collection of files and some configuration data, use a filesystem and a text file. Rob
next prev parent reply other threads:[~2018-05-22 20:01 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-04-17 9:10 [RFC 00/13] ARM: dts: DT overlay support infra + some data Tero Kristo 2018-04-17 9:10 ` [RFC 01/13] ARM: dts: allow building .dtb files under platform subdirs Tero Kristo 2018-04-19 0:02 ` Rob Herring 2018-04-17 9:10 ` [RFC 02/13] ARM: dts: add support for building DT overlays Tero Kristo 2018-04-17 9:10 ` [RFC 03/13] ARM: dts: add subdir for TI SoC DT files Tero Kristo 2018-04-17 9:10 ` [RFC 04/13] kbuild: add support for building %.dtbo targets Tero Kristo 2018-04-18 14:16 ` Geert Uytterhoeven 2018-04-17 9:10 ` [RFC 05/13] ARM: dts: ti: add support for building .dtb files containing symbols Tero Kristo 2018-04-18 14:20 ` Geert Uytterhoeven 2018-04-18 19:07 ` Tero Kristo 2018-04-18 22:43 ` Rob Herring 2018-04-19 6:36 ` Tero Kristo 2018-04-19 15:26 ` Rob Herring 2018-04-19 18:00 ` Tero Kristo 2018-04-17 9:10 ` [RFC 06/13] ARM: dts: am57xx-evm: add AM57xx-evm DT overlay Tero Kristo 2018-04-18 14:36 ` Geert Uytterhoeven 2018-04-18 19:12 ` Tero Kristo 2018-04-18 19:15 ` Russell King 2018-04-20 13:27 ` Geert Uytterhoeven 2018-04-18 22:40 ` Rob Herring 2018-04-19 0:19 ` Rob Herring 2018-04-19 6:49 ` Tero Kristo 2018-04-20 1:31 ` Rob Herring 2018-04-17 9:10 ` [RFC 07/13] ARM: dts: ti: add camera overlays Tero Kristo 2018-04-17 9:10 ` [RFC 08/13] ARM: dts: ti: add dra71-evm overlays Tero Kristo 2018-04-17 9:10 ` [RFC 09/13] kbuild: add support for generating FIT images Tero Kristo 2018-04-17 9:10 ` [RFC 10/13] ARM: dts: add FIT image build support for ARM architecture Tero Kristo 2018-04-17 9:10 ` [RFC 11/13] ARM: dts: ti: add FIT image dependencies Tero Kristo 2018-04-17 9:10 ` [RFC 12/13] ARM: dts: ti: add dra71-evm FIT description file Tero Kristo 2018-04-17 9:29 ` Russell King 2018-04-17 9:34 ` Tero Kristo 2018-04-17 14:49 ` Tony Lindgren 2018-05-21 6:57 ` Tero Kristo 2018-05-21 6:57 ` Tero Kristo 2018-05-22 20:01 ` Rob Herring [this message] 2018-05-22 20:01 ` Rob Herring 2018-05-23 5:55 ` Tero Kristo 2018-05-23 5:55 ` Tero Kristo 2018-05-23 14:13 ` Rob Herring 2018-05-23 14:13 ` Rob Herring 2018-05-23 18:37 ` Tony Lindgren 2018-05-23 18:37 ` Tony Lindgren 2018-05-29 17:05 ` Frank Rowand 2018-05-29 17:05 ` Frank Rowand 2018-05-29 17:33 ` Russell King - ARM Linux 2018-05-29 17:33 ` Russell King - ARM Linux 2018-05-29 22:45 ` Frank Rowand 2018-05-29 22:45 ` Frank Rowand 2018-05-29 22:51 ` Russell King - ARM Linux 2018-05-29 22:51 ` Russell King - ARM Linux 2018-04-17 9:10 ` [RFC 13/13] ARM: dts: ti: add am57xx-evm " Tero Kristo 2018-04-17 9:18 ` [RFC 00/13] ARM: dts: DT overlay support infra + some data Russell King
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