Marcin Juszkiewicz

Lot of people asked me how I managed to fry left speaker in my Chromebook. There are also few which said that it is Ubuntu fault.

So today I used recovery to wipe out my installation of Ubuntu from device and decided to check under Chromium OS. And yes, I got nice smell of burnt plastic etc coming from left speaker area.

Why? Because it is kernel bug. Not Ubuntu, ALSA or user. Ok, it is a bit of user’s fault cause you should not have to play with ALSA mixer. But you can — all binaries are part of Chromium OS stable.

So let me give you needed steps:

1. Boot Samsung Chromebook (ARM one) to Chromium OS
2. Login or use guest session
3. Run terminal (Ctrl+Alt+t)
4. Run “alsamixer -c0”
5. Set “Lineout” to highest value
6. Unmute everything what starts with “Left” or “Right” (depends which speaker you do not like)
7. Touch speakers (but better not for long)
8. Hold “Power” button to shut down before it will burn though your desk.

In normal situation I would assume that sound driver will take care of combinations which may break your hardware. But looks like Chromebook developers did had such idea.

Is this howto useful? I think it is. Cause if you have device broken in some way and you want to get it replaced you can just run it and hope for replacement instead of repair.

And when next time someone will write me “go and fix ubuntu rather than putting blame on samsung. Its Ubuntu which is the cause” like I got in recent comment I will just ban such person from commenting.

I bought many Samsung products. There were monitors, cellphones, storage and others. But I am starting to feel that it is time to change vendor…

All because Chromebook…

Device pushed to market in a big rush with kernel allowing users to burn devices. I really do not like smell of burnt speakers and plastics. Like Dylan Reid commented my Google+ post:

I’m guessing that a path was set up from MIC1 (wired to DMIC in) to the left speaker output. Playing the digital mic input as analog at full volume seems like something that might cause speaker failure, and wouldn’t necessarily be audible while it is happening.

My device runs Ubuntu 13.04, has UCM profiles installed to get sound working on what left from speakers but if application touch ALSA in wrong way then I have to open windows to get some air and get smoke out.

I never had such problems with all devices I played with. NEVER

I do a lot of cross compilations. With different software elements. But sometimes I want to kick their authors into ass…

There is a good sign when you see $(CC) in Makefiles as it shows that author of code learnt that “gcc” is not the only compiler. But this is not the only compiler you should know about.

Recently I was adding one component (will save a name) into OpenEmbedded as this is one of dependencies for some bigger project (which I do not want to blog about). Argh… I managed to cross built it but patches are UGLY (will get better).

Using $(CC) to build everything is just broken. Especially when you need to compile a tool which will generate some code to get everything built. There is $(BUILD_CC) for it but you have to use it wisely. If there are common parts then compile them with $(BUILD_CC) if you need to run it and with $(CC) if you not. This way we, cross compilation guys, can just do “./configure;make;make install;package” is it native or cross build. Autotools (die, die, die) are able to handle that — so is your code if you write Makefiles properly.

But do not reuse same object files for target and native binaries — let it be “common.o” and “native/common.o” for example. OK, if you do only native builds then it will take a bit more disk space but we have 2012 not 1995… Storage is cheap.

There is also $(HOST_CC) but that’s for other post…

Somewhere in 2010/11 I decided to clean up mess of naming machines at home and decided to go with character names from “Winnie the Pooh” books (Polish edition). Today I got new developer board and had to spend a moment to get a name for it.

So “klapouchy” (Eyeore) will be new name for DragonBoard. Maybe not best one but most of the names are already taken:

• krzys (Christopher Robin) is my router (because Chris decides who can enter Hundred Acre Wood which is the name of my WiFi network)
• puchatek (Winnie the Pooh) is main desktop
• lumpek (Lumpy) is conference laptop (it was lucek before because it got Ubuntu Lucid as first system)
• gofer (Gopher) is Efika MX Smartbook
• krolik (Rabbit) is Samsung Chromebook
• malenstwo (Roo) is Pandaboard (there were malenstwo-a1 and malenstwo-ea1 when I had two boards)
• prosiaczek (Piglet) was MX53 Quickstart
• kangurzyca (Kanga) is my wife laptop (she chosen the name)
• sowa (Owl) is another router
• tygrysek (Tigger) is my VPS (at beginning it was up/down/up/down all the time)

So most of the names from books are already taken. There are also Disney movies which adds few new ones (like Gopher and Lumpy) and cartoons (which I am not fan of). In worst case one day I will start re-using names or add names from other story.

What I used before? Desktop was “home” or “hrw”, Dell laptop (now “kangurzyca”) was “maluch” (small) due to 12” size, “lumpek” was “lucek” due to Ubuntu Lucid installed and rest was named by hardware name (which is a default in OpenEmbedded).

How you are naming your machines?

I created a project at Launchpad to have one place to gather hackers playing with ARM based Chromebook support in their distros.

Project is named “Cross distro support for Samsung Chromebook (ARM based)” and is maintained by team named “Samsung Chromebook (ARM) hackers“. If you want to join then you need to have Launchpad account and then join the team.

Why Launchpad instead of (insert any similar place)? Because I know it and it has very good bugtracker which allows to track other bug trackers. And it does not have to have anything related with Ubuntu…

OK, most of bugs now are about Ubuntu but that’s because I added them. But take a look at bug about ALSA UCM support. It affects our project but also affected “alsa-lib” and “alsa-utils” packages in Ubuntu. There is nothing which could stop us from adding links to Debian, Fedora, OpenSUSE or other distros bug reports there.

I added PPA there which will get binary packages for “raring” (unless they got merged) and backports for “quantal” and who knows, maybe one day even for “precise”. Due to policy that repository will not be able to build for “armhf” architecture but one of my personal ones can so I will copy packages.

So, who wants to join us? We already have non-Ubuntu people in the team!

During last days I spent some time in binutils, gcc, gdb, glibc, libffi repositories. All of them have GIT mirrors but most (if not all) are kept in CVS by default.

I used CVS in previous millenium just because I did not know good alternative. But I also know that move from it to other SCM can be painful.

But digging though commits because shortlog view is useless hurts… Exported patches need to be edited to drop all changes to many Changelog files. For libffi it is even better to grab patches from mailing list than from repository…

Life sucks, then you die^Whave to deal with CVS git repos.

When I bought Samsung Chromebook friend started “nbench” on it. So I did same on my conference laptop. None of devices won…

Idea of testing cpu power was sitting somewhere at back of my head and finally I decided to just run one simple command available on nearly every GNU/Linux based system: “openssl speed”. Sure, on some systems it will use hardware accelerators, on others (or not) some options enabled to get more speed (like ARM assembly version which is not enabled in Debian/Ubuntu systems). But it is something what anyone can run at home.

Table may be hard to decipher so I also give it as Google Docs. It also has few more devices listed and whole tables (one below is for 8192 size samples).

Devices in table are:

• my Intel Core i7-2600K desktop
• my Intel U7300 (ultra low voltage) conference laptop
• Exynos5 Dual powered Samsung ARM Chromebook
• Exynos4 Dual powered Tizen development platform (got rid of it today)
• i.mx515 powered Efika MX Smartbook
• Beaglebone with AM335x cpu
• Sheevaplug (as only armv5te device which can compare with other entries)

Devices were running different versions of OpenSSL under different systems. It is listed in Google Docs document.

Most interesting columns are U7300 and Exynos 5250 ones — 3 years old laptop which I bought for conferences compared to Chromebook. Looks like for next conferences/events I will rather go with Chromebook not UL30A. This will give me one or two hours of battery life less but it is much lighter device at same time. But have to test it first for few days to check is it comfortable enough for daily use.

Half year ago I got Tizen development platform device. Played a bit with it and then put in a drawer due to other things to do.

Today I looked again at Tizen. Nothing changed. Git repositories still scream “*@#$!$ *** you developers!” due to lack of any commits other than code drop bombs.

So if someone (from Europe) wants this device — be first to comment. Sending with DHL and you pay for posting.