From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH V2 2/2] kbuild: dtbs_install: new make target
Date: Tue, 19 Nov 2013 14:06:05 -0700 [thread overview]
Message-ID: <528BD2BD.8090304@wwwdotorg.org> (raw)
In-Reply-To: <20131119203923.GF28859@titan.lakedaemon.net>
On 11/19/2013 01:39 PM, Jason Cooper wrote:
> On Tue, Nov 19, 2013 at 12:53:07PM -0700, Stephen Warren wrote:
...
>> d) Finally, boot.scr needs to load the DTB. This requires knowing which
>> DTB to load. Again, the distro shouldn't have to detect which board
>> they're running on, and either install the correct DTB to a static
>> filename, or make a decision on the DTB filename to load. Instead,
>> distros should simply install all DTBs generated by the kernel build,
>> and use some run-time information to calculate the DTB filename using a
>> completely HW-agnostic and generic algorithm.
>>
>> To support this, U-Boot can be configured to add certain standard
>> environment variables to the default environment. These define which SoC
>> and board the code is running on. These are ${soc} and ${board}. If you
>> then calculate the DTB filename as ${soc}-${board}.dtb, that should work
>> anywhere. This is why keeping the current in-kernel DTB filenames is
>> important, so they match the assumption that this algorithm works.
>>
>> Note: if the firmware contains an embedded DTB, boot.scr could detect
>> this e.g. by the standard variable $fdt_addr being set, and hence skiip
>> loading a DTB. IIRC, this is how Calxeda boards are set up.
>
> Ok, so the ${soc}-${board} is a work-around until all bootloaders are
> providing a dtb, or until all bootloaders are providing a stable dtb?
I suppose so yes.
However, I'm not really convinced we'll see that many products with a DT
embedded into them that's stable, complete[1], and based on upstream
bindings, in the particularly near future. I think distros will likely
need to deal with DTs-in-filesystems for a while yet. But anyway, either
way should work out just fine.
[1] For example, we aren't that far off some reasonably stable basic
bindings for Tegra now . However, there are still devices we haven't
added to DT at all, so while the DT ABI stability issue is fading, the
need-to-upgrade-your-DTB case still exists to get new features, and
upgrading the DTB via the filesystem is a lot easier and more convenient
than doing so via firmware updates or firmware flashing commands.
next prev parent reply other threads:[~2013-11-19 21:06 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-11 20:29 [RFC DTC PATCH] dtc: add symlink (-L) output to dtbs Jason Cooper
[not found] ` < 1385942188-21831-1-git-send-email-jason@lakedaemon.net>
[not found] ` < 52814AFB.3070600@wwwdotorg.org>
[not found] ` < CAL_Jsq+mAoN2Lbg+uqfLMTZBvgz28E-EioiaU4BUSL_7rS5JjA@mail.gmail.com>
[not found] ` < 528275B7.6050209@wwwdotorg.org>
[not found] ` < 1385062552-9882-1-git-send-email-jason@lakedaemon.net>
[not found] ` < 653B066B-5B24-4817-86EF-D4D9F129123D@codeaurora.org>
[not found] ` < 20131115121215.901EFC40885@trevor.secretlab.ca>
[not found] ` < 1384896475-8744-1-git-send-email-jason@lakedaemon.net>
2013-11-11 21:24 ` Stephen Warren
2013-11-12 14:51 ` Jason Cooper
2013-11-12 15:29 ` Rob Herring
2013-11-12 18:38 ` Stephen Warren
2013-11-12 19:30 ` Jason Cooper
2013-11-12 19:40 ` Andrew Lunn
2013-11-12 20:08 ` Jason Cooper
2013-11-12 20:15 ` Stephen Warren
2013-11-14 16:28 ` Jason Cooper
2013-11-14 19:00 ` Stephen Warren
2013-11-14 19:16 ` Jason Gunthorpe
2013-11-14 19:34 ` Russell King - ARM Linux
2013-11-14 21:37 ` Stephen Warren
2013-11-14 22:12 ` Matt Sealey
2013-11-15 16:14 ` Grant Likely
2013-11-14 19:26 ` Russell King - ARM Linux
2013-11-15 15:23 ` Jason Cooper
2013-11-15 17:09 ` Javier Martinez Canillas
2013-11-15 21:38 ` Jason Cooper
2013-11-15 12:12 ` Grant Likely
2013-11-15 15:21 ` Jason Cooper
2013-11-18 12:56 ` Grant Likely
2013-11-18 18:38 ` [RFC PATCH V2 0/2] Add 'make dtbs_install' Jason Cooper
2013-11-18 18:38 ` [RFC PATCH V2 1/2] dtc: add 'compat' output option, prints board string Jason Cooper
2013-11-18 19:01 ` Stephen Warren
2013-11-18 19:21 ` Jason Cooper
2013-11-18 20:24 ` Jason Cooper
2013-11-18 18:38 ` [RFC PATCH V2 2/2] kbuild: dtbs_install: new make target Jason Cooper
2013-11-18 19:09 ` Stephen Warren
2013-11-18 19:19 ` Jason Cooper
2013-11-18 19:23 ` Stephen Warren
2013-11-18 19:28 ` Jason Cooper
2013-11-18 19:38 ` Stephen Warren
2013-11-18 19:52 ` Jason Cooper
[not found] ` < 528A98C8.9040803@wwwdotorg.org>
2013-11-18 22:46 ` Stephen Warren
[not found] ` <20131119122801. GL16735@n2100.arm.linux.org.uk>
2013-11-19 12:28 ` Russell King - ARM Linux
2013-11-19 14:23 ` Jason Cooper
[not found] ` < 20131119150212.GM16735@n2100.arm.linux.org.uk>
2013-11-19 15:02 ` Russell King - ARM Linux
[not found] ` <20131119152047. GB28859@titan.lakedaemon.net>
2013-11-19 15:20 ` Jason Cooper
2013-11-19 15:21 ` Russell King - ARM Linux
[not found] ` < 20131119192246.GP16735@n2100.arm.linux.org.uk>
2013-11-19 19:22 ` Russell King - ARM Linux
2013-11-19 19:54 ` Jason Cooper
2013-11-20 13:10 ` Grant Likely
2013-11-20 13:56 ` Russell King - ARM Linux
2013-11-21 7:50 ` Grant Likely
2013-11-20 16:38 ` Jason Cooper
2013-11-19 18:40 ` Stephen Warren
2013-11-19 18:43 ` Jason Cooper
2013-11-19 18:42 ` Stephen Warren
2013-11-19 18:52 ` Russell King - ARM Linux
2013-11-19 19:27 ` Stephen Warren
2013-11-19 19:53 ` Russell King - ARM Linux
2013-11-19 18:57 ` Jason Cooper
2013-11-19 19:53 ` Stephen Warren
2013-11-19 20:39 ` Jason Cooper
2013-11-19 21:06 ` Stephen Warren [this message]
2013-11-20 13:18 ` Grant Likely
2013-11-18 21:21 ` [RFC PATCH V3 0/2] Add 'make dtbs_install' Jason Cooper
2013-11-18 21:21 ` [RFC PATCH V3 1/2] scripts: dtc: build fdtget for extracting properties from dtbs Jason Cooper
2013-11-18 22:54 ` Stephen Warren
2013-11-19 14:17 ` Grant Likely
2013-11-18 21:21 ` [RFC PATCH V3 2/2] kbuild: dtbs_install: new make target Jason Cooper
[not found] ` <cover. 1384798508.git.jason@lakedaemon.net>
[not found] ` < 728deb9bbeab491a728da077aa5e47c0e01bccf8.1384798508.git.jason@lakedaemon. net>
[not found] ` <728deb9bbeab491a728da077aa5e47c0e01bccf8.1384798508.git.jason@lakedaemon.n et>
2013-11-19 13:58 ` [RFC PATCH V2 1/2] dtc: add 'compat' output option, prints board string Grant Likely
[not found] ` <cover. 1384809305.git.jason@lakedaemon.net>
[not found] ` < 13f06582c166343c055b8793305d4b9a00b2172e.1384809305.git.jason@lakedaemon. net>
[not found] ` <13f06582c166343c055b8793305d4b9a00b2172e.1384809305.git.jason@lakedaemon.n et>
2013-11-19 14:22 ` [RFC PATCH V3 2/2] kbuild: dtbs_install: new make target Grant Likely
2013-11-19 21:27 ` [PATCH V4] " Jason Cooper
2013-11-19 21:58 ` Stephen Warren
2013-11-20 13:21 ` Grant Likely
2013-11-20 17:22 ` Jason Cooper
2013-11-20 17:08 ` Jason Cooper
2013-11-20 17:21 ` Stephen Warren
2013-11-21 7:48 ` Grant Likely
2013-11-21 19:35 ` [PATCH V5] " Jason Cooper
2013-11-21 19:55 ` Stephen Warren
2013-11-21 23:31 ` Kumar Gala
2013-11-21 23:36 ` Olof Johansson
2013-11-22 7:42 ` Grant Likely
2013-11-22 13:31 ` Jason Cooper
2013-11-22 13:19 ` Jason Cooper
2013-12-01 23:40 ` Jason Cooper
2013-11-22 7:44 ` Grant Likely
2013-11-22 13:33 ` Jason Cooper
2013-12-01 23:56 ` [PATCH V6] " Jason Cooper
2013-12-03 17:37 ` Stephen Warren
2013-12-03 17:41 ` Russell King - ARM Linux
2014-01-10 18:29 ` Jason Cooper
2014-02-04 12:40 ` Grant Likely
2015-03-28 13:23 ` Russell King - ARM Linux
2015-03-28 13:37 ` [PATCH] dtbsinstall: don't move target directory out of the way Russell King
2015-03-28 15:59 ` Jason Cooper
2015-03-28 15:58 ` [PATCH V6] kbuild: dtbs_install: new make target Jason Cooper
2015-03-29 20:34 ` Olof Johansson
2015-03-29 20:58 ` Russell King - ARM Linux
2015-03-29 21:04 ` Jason Cooper
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