Enclosed you'll find a link to the agenda, notes and actions from the
Linaro Developer Platforms Weekly Status meeting held on March 23rd
in #linaro-meeting on irc.freenode.net at 16:00 UTC.
http://wiki.linaro.org/Platform/DevPlatform/Meetings/2011-03-23
Actions from the meeting where as follows:
* slangasek to get dpkg-shlibdeps (and other fixes) uploaded to natty
* kunal to publish FTBFS kdebase-workspace to ppa for multiarch debugging
Regards,
Tom (tgall_foo)
Developer Platforms Team
"We want great men who, when fortune frowns will not be discouraged."
- Colonel Henry Knox
w) tom.gall att linaro.org
w) tom_gall att vnet.ibm.com
h) tom_gall att mac.com
I had great hopes of doing these status reports once a week; but it
turns out to take more effort to get together that I estimated.
Here's the status of ARM device tree support as of today. As always,
let me know if you have any corrections or additional information.
1 - Latest news
---------------
- The last vestiges of of_platform_bus_type are gone from Linus' tree
as of the 2.6.39 merge window. Everything should be using
platform_device now.
- devicetree/arm on git://git.secretlab.ca/git/linux-2.6 has
everything needed to turn on basic device tree support for any
platform.
- Support has been added for Versatile and Tegra in devicetree/arm
- Support for Samsung s5pv310 and Freescale mx5 are in devicetree/test
- Similarly, u-boot needs to have the CONFIG_OF_LIBFDT and
CONFIG_SYS_BOOTMAPSZ defined to turn on device tree support.
- I've also got patches that eliminate the need for
CONFIG_SYS_BOOTMAPSZ which I'll post shortly, but they're not quite
working yet.
- I've also got a trivial patch that should enabled CONFIG_OF_LIBFDT
on a large set of boards, but it has had pretty much zero testing.
:-)
- Jason Hui has been making awesome progress on mx5, and some of their
patches are in devicetree/test. Hopefully to move over to
devicetree/arm soon.
- Shawn Guo has also been making good progress on adding the clock
bindings to the mx5 support. There are still questions up in the air
about the best way to handle clocks though. While all the clocks
/can/ be converted to device tree data, there is also value in sharing
clock initialization data between DT and non-DT board support. The
of_platform_device_prepare() work mentioned below will help with that.
It will also be easier to work on the clock support when the common
struct clk patch series from Jeremy gets merged. Until then there
ends up being a lot of duplication of code.
- Lennert has a series of virq patches for ARM patches completed. He
is currently working on cleaning them up to get them posted.
- Patches posted for of_platform_prepare() which makes it easier for
static platform_device registrations to co-exist with device tree
data. Patches are currently in devicetree/test, and will move to
devicetree/arm shortly.
- Basic DT support has been merged into Nicolas' Linaro kernel tree.
- DT is also working on Versatile Express, OMAP, and the new Xilinx
platform, but I don't have patches for either of those platforms in my
tree.
- Rob Herring's work on the early dtb mmu maping is mainlined and
makes it much nicer to work with dtbs.
Next steps:
--------------
At this point I'm putting on my Linaro hat. Feel free to tune out
past this point if you're not interested how DT support will
materialize in the next release.
There are a number of very specific tasks that need to be completed
for the 11.05 release. The goal is to have basic device tree support
turned on and working on all of the platforms supported in the
release. There isn't a lot of time to get this pulled together, but
all the infrastructure is in places, so most of the work is turning on
the configuration options and testing the platforms.
For each board, I need an engineer to do the following:
1) Enable CONFIG_OF_LIBFDT and CONFIG_SYS_BOOTMAPSZ against the Linaro
u-boot tree.
2) Enable CONFIG_OF and CONFIG_PROC_DEVICETREE in the kernel
3) Add something like the following to the *existing* machine
definition. For initial basic support, you don't need to create a
separate <soc>-dt.c board support file yet.
+static const char *omap4_panda_dt_match[] __initdata = {
+ "ti,omap4-panda",
+ NULL
+};
+
MACHINE_START(OMAP4_PANDA, "OMAP4 Panda board")
[...]
+ .dt_compat = omap4_panda_dt_match,
MACHINE_END
The string in the match table should be in the form "<vendor>,<board-name>"
4) Add a template .dts file for the board in
arch/arm/boot/dts/<board>.dts. The following should be sufficient:
/dts-v1/;
/ {
model = "TI OMAP4 PandaBoard";
compatible = "ti,omap4-panda";
#address-cells = <1>;
#size-cells = <1>;
aliases {
};
memory {
device_type = "memory";
reg = <0x80000000 0x08000000>;
};
chosen {
};
};
5) test it :-)
6) send patches to me for inclusion in the Linaro U-Boot and Kernel
trees. I'll collect them to start and ask John and Nicolas to pull
them into their trees when they're ready.
This is enough for very basic device tree support and I expect it will
only take a day or so of effort to get completed. It won't be
particularly useful, but it ensures that the infrastructure is enabled
and working.
Bonus points if you're also able to provide patches that add
of_platform_device_probe() and of_platform_bus_populate() calls to the
board support so that device nodes get attached to the devices and can
be used for attaching things like gpios, spi devices, and i2c devices.
This is a nice to have for 11.05, but it isn't a requirement to have
it working on all boards.
Here is the list of hwpacks that should be supported to the best of my
knowledge. Please reply with the hwpacks you can take responsibility
for:
efikamx
igep
imx51
omap3-x11-base
omap3
overo
panda
s5pv310
vexpress
There are also some specific cross-platform tasks that need some love.
Let me know if you can take responsibility for any of these items.
- Eliminate CONFIG_SYS_BOOTMAPSZ dependency from U-Boot. I've got a
patch series that does this, but it is untested. I'll post the series
tomorrow.
- Add packaging of .dtb files into linux-image-linaro-* packages.
Loic and I discussed putting them under /lib/dtb/`uname -r`/, but
thinking about it more, it might make more sense to share the modules
directory and use /lib/modules/`uname -r`/dtbs. The dtc tool needed
to build the .dtbs is included with the kernel tree.
- Add relevant dtb files to boot partition in linaro-image tools
- Add boot script which passes dtb as 3rd argument to 'bootm'
For purposes of tracking, I'll register bugs for the above items in
the Linaro bug tracker tomorrow.
Cheers,
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
[PATCH] ARM: device-tree: Add basic device tree support for Beagleboad
Note, no corresponding U-Boot changes to U-Boot are required as the
Linaro version already has these.
Hi there,
i have seen what you've started to implement with the Android Build service.
I am wondering if:
- all the source code / tools you've put in place is available (source code)
- how easy (or not) would that be to deploy this infrastructure 'internally'
so that we can use it for private builds for example?
- what are the requirements on the 'server/host' to be able to replicate
this setup?
thx,
nicolas
Hello everyone,
As I've been working on the integration of the latest developments and
fixes from upstream into the linaro-2.6.38 kernel lately, it became
quickly evident that major merge conflicts were to be expected. The
problem stems from the fact that we opened the 2.6.38 branch early i.e.
around the 2.6.38-rc5 kernel. Many patches that were merged into the
Linaro kernel have been subsequently modified by their respective
maintainers until they were merged upstream, meaning that what we have
now in mainline is different from what the Linaro kernel tree has. This
creates several issues:
- It is hard to verify that what is in the Linaro tree is actually the
latest and the best version of a patch.
- Merging additional fixes from upstream often ends up in merge
conflicts requiring manual resolution, sometimes non-trivial ones,
which is in itself a bug hazard.
- People wanting to contribute patches to the Linaro kernel potentially
have to create a different patch than what they would submit
upstream.
Given those issues, I decided to rebuild the linaro-2.6.38 branch from
scratch to see where that would bring me. And as could be expected, the
result looks nicer and it is much easier to work with than the current
tree. For example, this allowed me to merge the latest OMAP support
from mainline as is, including the latest fixes, without any need for
backport work nor major conflict resolution. Another advantage is that
the commit SHA1 references are now identical in most cases to what can
be found into mainline.
So... my question is: should we switch to this rebuilt tree or not?
There are drawbacks with such a move of course:
- All the testing done so far would be void. This is however not as
bad as this may look as the rebuilt kernel contains fixes for existing
bugs in the current tree, and the rebuilt kernel is using patches
that have and still are being tested by a wider community.
- I didn't forward port a couple series of patches that are available
in the current Linaro tree and not in mainline yet, including:
* DT support (Grant Likely)
* DVFS and PM for OMAP (Vishwanath Sripathy, Vishwanath BS)
* Some ux500 fixups (Linus Walleij)
* clock debug information (Yong Shen)
* Samsung CPUIDLE (Amit Kachhap)
So I would prefer if the people responsible for those patches did
resubmit their patches once they apply to the new tree (that should
be even easier now to apply patches that were meant for mainline).
- The history of the rebuilt tree is obviously different from the
current tree's. This means special care when updating to the new
tree with Git.
But overall I think there are more advantages than disadvantages for
such a move. What other people think?
The current rebuilt tree can be seen at:
http://git.linaro.org/gitweb?p=kernel/linux-linaro-2.6.38.git;a=shortlog;h=…
or obtained from:
git://git.linaro.org/kernel/linux-linaro-2.6.38.git (the "rebuilt" branch)
Nicolas
Hi,
We are looking for volunteers who could run demos and short tutorials at
the technical showcase we are organizing at LDS.
In particular, we hope that the landing teams will be able to show the
newest community boards in action, which almost nobody has seen in real
life yet. Here are suggestions:
* Power management demos, showing suspend/resume/hibernation and the
time they take, measuring power on the board, using powerdebug...
* Debugging quick tutorial
* perf demos
* Toolchain performance benchmarks
* Video codec performance benchmarks
* Demos of new QEMU targets
* linaro-media-create quick tutorial
* Device tree demo
* Linaro Android Build Service
* ... and anything useful you could think of, typically advertising
for your contributions to Linaro!
The main goal would be to advertise our work, both internally and
externally, and then start interesting discussions, and hopefully end up
with improvements and new ideas.
We will try to videotape some demos and publish them on YouTube if
appropriate. There should also be a vote for the best demos and prizes
will be given away.
I let Kiko and others add their own suggestions.
See https://wiki.linaro.org/Events/2011-05-LDS/Showcase/ for details
about the event.
Thanks in advance,
Cheers,
Michael.
--
Michael Opdenacker, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
+ 33 621 604 642
Hi Folks,
As some of you may remember, Linaro engineers have access to free DS-5
licenses.
If you don't know what DS-5 is, you can stop reading now ;-)
If you know what DS-5 is, you may also use it, either on daily basis or
just occasionally? I'd be most grateful for letting me know about it.
It's nearly 5 months since I presented it at UDS, so I'd love to know
whether you found it useful by now.
I know that at least some of you tried it, so simple "yes, use it every
day, love it" or "well, sometimes, if there's nothing better to do" or
maybe "naaah, it's absolutely rubbish" will do. Of course don't hesitate
to elaborate more :-)
Cheers!
Paweł
