Linus Torvalds released Linux 3.9 and many websites published summaries what’s new in it. One of common entries is support for ChromeOS laptops. But what that means for Samsung ARM Chromebook users?

Let’s start with Kernel Newbies summary which lists 5 commits:

• Platform: x86: Add Chrome OS Laptop driver
• Platform: x86: chromeos_laptop – Add Acer C7 trackpad
• Platform: x86: chromeos_laptop – Add HP Pavilion 14
• Platform: x86: chromeos_laptop – Add Pixel Touchscreen
• Platform: x86: chromeos_laptop – Add Taos tsl2583 device

None of them are for ARM Chromebook. But that does not mean that nothing was done for it. Touchpad driver was merged, many Exynos platform changes were made but yeah — still lot to do.

But that’s a curse of ARM platforms…

UPDATE: Arnd Bermann wrote a comment on my Google+ post that Olof Johansson has “linux-next” bootable on ARM Chromebook. YAY!

UPDATE: I got ChromeOS 3.8 kernel running on my Chromebook. Needs some testing and then will land in “saucy” as default one probably.

All rights reserved © Marcin Juszkiewicz
Linux 3.9 and Chromebook support was originally posted on Marcin Juszkiewicz website

This year I spent Easter in other way than in past years. Instead of staying with the family I went for demoscene party — Revision 2013 in Saarbrücken.

Please note (RSS readers mostly) that this post will contain many YouTube videos embedded. Please go to my blog to have them properly displayed (I use WordPress + Jetpack plugin to embed them).

Friday

Took us 12 hours to get there (mostly due to waiting on TXL and FRA airports) but we managed to be at party place around 19:00 on Friday. Registered, met friends and went to Kirchberg Hotel to drop bags.

Hotel has two stars but was perfectly fine for such trip as our. Clean bed, good breakfast, quiet place (except church bells at 10:00 on Sunday). All just ~2km from E-Werk where Revision took place.

Back to party, more people to meet, discuss a bit with guys from ARM Ltd about Samsung Chromebook, Cortex-A15, Mali etc. One guy joined with his Chromebook and recognized me when I asked “may I fry your speakers?” :D

Timetable listed one interesting thing: “Curio’s 2012 Essentials” which was ~1 hour long set of PC demos from previous year. It was nice as I was totally out of PC scene so was able to check how it looks.

Taxi to hotel was just 6€ ;D

Saturday

Attended “How to start writing compilers without a Ph.D” seminar as it sounded interesting to me. And it was ;) Video below:

Also had discussion with ARM guys about presenting not only technical demos (like Unreal Engine one) but also to show some demoscene productions. Soon “Beginnings” by Elude started on one of Nexus 10 tablets and was working nice. But coder who wrote it was not so happy about that when we discussed that later… I think that it would be a good thing for ARM Mali team to get some good demoscene groups to write demos for Android platform to amaze people with nice looking productions. ARM even had seminar for OpenGLES 3.0 API:

But Saturday was also full of competitions. Tracked music, oldskool music (read: 8-bit mostly), photo, animation/video, game, ascii/ansi, Amiga intros, PC 4K intros, Oldskool demos (8-bit, Atari STE, Amiga 500)…

There were many entries in compos where productions from long time no see groups/people were presented. For example in oldskool demo we got “RINK A DINK REDUX” from Lemon which was astonishing:

There were also demos for Amstrad CPC, MSX1, ZX Spectrum, Commodore 64 and other platforms. Oldskool music compo had even NES entry ;)

But it was also visible that demoscene is not full of amateurs like it was years ago. Some of videos in animation/video compo had professional level. “Lübeck 24x7x365″ took 50 days of recording but was really nice:

There was a concert in the evening… Ear plugs were not strong enough for me so I spent most of time outside talking with people. Next time need to take some better hearing protectors…

Sunday

As Saturday ended really late for us and competitions were planned for 13:00 we decided to not rush and stay in bed longer :) But at around 10:00 bells in local church started their music compo so we were not able to sleep anymore.

We got music, graphics, wild and of course PC 64K intro, web browser demo/intro, Amiga demo and PC demo competitions that day.

Graphics one was won by “Double Trouble by the Royal Forces” made by forcer & prince. Huge amount of details which was not so visible on big screen as it was on a tunnel’s wall where it was hanging as few square meters photo copy.

Wild compo… Man, that was something great. From productions made for Arduino (with some shields) though ARM Cortex-M3 one to interesting hack by Dexter/Abyss which shown one view on monochrome TV and second on oscilloscope while both were connected to Composite video signal only… See it for yourself (or grab separate entries from scene.org FTP server):

Then DJ set by h0ffman (skipped by me) and clue of party — Amiga and PC demos/intros. Different quality but most of them was really good — both from technical or design view (but not always from both at same time).

But as I am not a coder I looked mostly at design and audio/video part. All those names like ‘ray matching’ etc meant nothing to me so when someone tried to explain why demo which I did not like was so great I just told similar thing ;D

Monday

Wake up, breakfast, pack, pay, go to party place. We did not manage to get there before voting ended so not voted for PC demo compo entries. Greeted those who was still present, discussed a bit and then return trip… This time just ~9 hours but next time (if there will be such) we plan to go there by car. Less time needed.

Random stuff

I liked how party was organized — it was my first such event abroad and many people told me that Revision is the last demoscene party in old style. I really liked it. Saw many different platforms like MSX1, MSX2, C= VIC20, Amstrad CPC or Videoton…

Due to Easter time shops where closed on Sunday/Monday but it was not a problem for me as there was free coffee/tea, beer/water/orange juice was available to buy at low price (2.5€ for 0.5l beer) and there was hot food served all time (like 10:00 – midnight) also not so expensive.

Weather could be better as it was cold but at least there was no snow (which we still have here).

It was also nice to see Kiero at work as he was finishing “Machinist” Amiga demo on his x86-64 laptop with WinUAE running fullscreen. I was surprised that ASUS UL30A is capable to run it fast enough.

Amount of discussions with people is probably uncountable. Chromebook, ARM, Android, Amiga, scene were just subset of topics…

Will I go there next year? Will see…

All rights reserved © Marcin Juszkiewicz
Revision 2013 was originally posted on Marcin Juszkiewicz website

Today Alan Pope was surprised that I am using Midnight Commander. It was not the first time when I saw such reaction.

Why am I using mc? It is “simple” tool, works fine and I know it. Some of its features are useless today (like /#sh: way of handling copying over ssh which got replaced by sshfs) but if it works why I should abandon it? I can use it remotely (try it with Nautilus/Dolphin/Thunar), on every type of terminal (but was incredibly hardcore on HP2623A one).

But thing which I love it in is “patchfs”. It allows to handle diffs like archives but with read/write operations. I can remove not wanted parts from patch without going into editor. When I was dealing with crazy/huge patches I was able to clean them in few minutes

All rights reserved © Marcin Juszkiewicz
Yes, I am using Midnight Commander was originally posted on Marcin Juszkiewicz website

Over year ago I wrote How to cross compile ARM kernel under Ubuntu 10.10 and this became one of most popular posts on my website. It may work still but it is terribly outdated so I decided that it is a time for update.

Users of Ubuntu 12.04 ‘precise’ have much simpler situation when it comes to cross compilation of Linux kernels than ones who use older releases. Everything is now in distribution, we have a lot of packages converted to multiarch so instruction is much shorter.

There are few steps to cross compile Linux kernel under Ubuntu 12.04 ‘precise’ (for “armhf” which is officially supported now):

• Install cross compiler:

apt-get install gcc-arm-linux-gnueabihf

• Fetch kernel source:

apt-get source linux-source-3.2.0

• Install packages required to build kernel:

apt-get build-dep linux-source-3.2.0

• Build kernel:

cd linux-3.2.0; dpkg-buildpackage -b -aarmhf

And that’s all. Linaro kernels will be as easy to build as Ubuntu one on next days as we have to update packaging to recent Ubuntu version.

All rights reserved © Marcin Juszkiewicz
Ubuntu 12.04 ‘precise’ and cross compilation of ARM kernels was originally posted on Marcin Juszkiewicz website

Now, when Linus Torvalds released Linux 3.0-rc many people are trying to update to this version. I did it recently on one of my machines and decided to share instructions with others.

For Ubuntu ‘natty’ 11.04 users the easiest way is to use packages from ‘oneiric’ 11.10 release. There are few ways of doing that.

Grab packages way

Not best option but easy do to and does not require lot of work — just need to grab three packages:

• Linux 3.0 kernel image — select newest version and required flavour (generic/server/virtual)
• module-init-tools — version 3.13 is required to get modules working, 3.16 is now available in oneiric
• procps — to make ‘ps’ not complain due to lack of 3rd digit in kernel version

Then install resulting debs and reboot computer.

APT pinning way

This method requires editing system configuration but is nicer. You need to create file (’30-pinning’ for example) in /etc/apt/preferences.d/ directory with this contents:

Package: *
Pin: release n=natty
Pin-Priority: 900

Package: *
Pin: release n=oneiric
Pin-Priority: 800

This will tell APT that packages from ‘natty’ 11.04 release are what we want but ‘oneiric’ 11.10 ones can also be installed.

Then next step is adding ‘oneiric’ repositories. I did it by going to /etc/apt/sources.list.d/ directory and making copy of ‘natty.list’ as ‘oneiric.list’ + search/replace ‘natty’ -> ‘oneiric’. Then use your preferred package manager frontend and install packages from first method — with “apt-get” it would be:

apt-get install -t oneiric linux-image-3.0-1-generic module-init-tools
apt-get install -t oneiric procps

funny note

My machine has two 50mm fans which were very loud with 2.6.39 kernel (something ~4700rpm). Under 3.0-rc3 they are unnoticeable at 1700-2700rpm only.

All rights reserved © Marcin Juszkiewicz
Linux 3.0 under Ubuntu ‘natty’ 11.04 was originally posted on Marcin Juszkiewicz website

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So you got ARM device and want to build kernel for it? There are few ways how you can do it under Ubuntu 10.10 (or higher).

First you need proper cross compiler. After “apt-get install gcc-arm-linux-gnueabi” you will get proper one.

Next step is compilation of kernel. I will cover 2 things: Ubuntu kernel packages and own kernel.

So… to cross compile Ubuntu kernel we need to have some libraries installed in ARM versions. Simplest way is to use “xdeb” for it:

# apt-get install xdeb
# xdeb -aarmel --only-explicit --apt-source linux-linaro

This will fetch some libraries and install it in host system. But it will not build kernel for us :( Filled bug to not lose track of it.

NOTE: check “dpkg -l *elf*-armel-cross” after xdeb run. If it does not return anything then you need to edit “/etc/apt/source.list” and add line with “deb-src” so APT will know where to go for sources. Do not forget to run “apt-get update” after edit.

Next step is quite simple — all is needed is:

$ cd linux-linaro-2.6.35
$ CROSS_COMPILE=arm-linux-gnueabi- dpkg-buildpackage -b -aarmel

After some time kernel will be cross compiled and packaged.

If you want official Ubuntu kernel instead of Linaro one then use:

$ apt-get source linux-source-2.6.35
$ cd linux-2.6.35
$ CROSS_COMPILE=arm-linux-gnueabi- dpkg-buildpackage -b -aarmel

Other way (not supported by Ubuntu developers) is to build kernel from source outside of Ubuntu. Once you got sources unpacked and configured you need just one command: “ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- make uImage modules” to build kernel (replace uImage with zImage if your device does not use U-Boot).

All rights reserved © Marcin Juszkiewicz
How to cross compile ARM kernel under Ubuntu 10.10 was originally posted on Marcin Juszkiewicz website

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Related posts:

1. Ubuntu cross compilers – part 2
2. Ubuntu cross compilers
3. UDS-N: Monday