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Free Electrons is not in the system administration business (we offer free and open-source solutions for embedded systems), but we do our best to share whatever experience we acquire, and whatever code we produce.

We configured a KVM virtual machine to run our mailing lists, and we used Ubuntu 10.04, the long term support (LTS) version. Here are instructions based on this experience. You could also use the same instructions to install Ubuntu 10.04 on a tiny, low power ARM board. And if you wish to use a more recent version of Ubuntu, I expect the steps to be very similar.

Here we assume that your domain is example.com and that you install your mailing list software on lists.example.com. It is indeed a good idea to install your mailing list software on a different server. This way, you won’t mess up with your main web and mail servers. Not having CGI scripts running on it will also keep your main mail server more secure.

Install packages

Install the Apache web server. It will allow administrators to configure and manage the lists, and users to subscribe, unsubscribe and tune their subscription settings.

sudo apt-get install apache2

For e-mail delivery, I chose the Postfix MTA (Mail Transport Agent). Exim would have been a good solution too, but I am more familiar with Postfix, which is already in use on our main mail server.

sudo apt-get install postfix

Choose the Internet site option.

Now install the mailman package:

sudo apt-get install mailman

Select the languages that you want your mailing list interfaces to support. I chose English and French for the moment. To add more languages later, run:

sudo dpkg-reconfigure mailman

Configure the Apache web server

First copy the sample Apache configuration file provided by the mailman package:

cp /etc/mailman/apache.conf /etc/apache2/sites-available/mailman

Now, in /etc/apache2/sites-available/mailman, enable short URLs by enabling:

ScriptAlias /mailman/ /usr/lib/cgi-bin/mailman/

Also modify /etc/mailman/mm_cfg.py:

DEFAULT_URL_PATTERN = 'http://%s/mailman/'

The last step is to enable your mailman site in Apache:

sudo a2ensite mailman
sudo /etc/init.d/apache2 restart

You should now have a new symbolic link in /etc/apache2/sites-enabled/.

Check that the Mailman website works by opening your mailing lists home page: http://lists.example.com/mailman/listinfo. It should look like http://lists.free-electrons.com/mailman/listinfo.

Configure postfix

Enable the following line in /etc/mailman/mm_cfg.py:

MTA='Postfix'

Once the MTA is configured, generate Mailman specific aliases for Postfix:

sudo /usr/lib/mailman/bin/genaliases

Now, you need to configure Postfix through its main.cf file. A convenient way to do this is to run the below commands:

sudo postconf -e 'relay_domains = lists.example.com'
sudo postconf -e 'transport_maps = hash:/etc/postfix/transport'
sudo postconf -e 'mailman_destination_recipient_limit = 1'
sudo postconf -e 'alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases'

Also add the following line to /etc/postfix/transport:

lists.free-electrons.com      mailman:

and run:

sudo postmap -v /etc/postfix/transport

You won’t have any mail delivery if you forget. I struggled for a few hours before I realized I forgot this setting.

Now, set correct file ownership:

sudo chown root:list /var/lib/mailman/data/aliases
sudo chown root:list /etc/aliases

For logging and debugging e-mail delivery, I recommend to install the sysklogd package. Without it, you won’t have any mail.info, mail.warn and mail.err files in /var/mail/.

To install this package, enable the universe repository if needed (uncomment the lines with universe in the /etc/apt/sources.list file), and run:

sudo apt-get update
sudo apt-get install sysklogd

To avoid having two mail.info and mail.log files with identical contents, edit /etc/syslog.conf and remove the below line:

mail.*                          -/var/log/mail.log

Also create a /etc/logrotate.d/mail file to rotate logs, as in the below example:

/var/log/mail.* {
        daily
        size 10M
        rotate 4
        compress
        missingok
        notifempty
        create 640 root adm
}

Last but not least, restart Postfix:

/etc/init.d/postfix restart

At this point, a good idea is to check that mail delivery works:

sudo apt-get install bsd-mailx
mailx alice@example.com
Subject: test
test
.
Cc:

Note: that’s the line containing only a dot character that allows to terminate the message.

If the receipient doesn’t receive this message, there is an issue in the way your mail server is configured. This could be because the firewall doesn’t allow connections to outside machines through tcp port 25. Anyway, look at the logs in /var/log/mail.* to get a clue. There is no point going on in this howto until you get this fixed.

Creating the mailman site list

Mailman needs a so-called “site list”, which is the list from which password reminders and such are sent out from. The default name for this list list mailman, though you can change this through the MAILMAN_SITE_LIST setting in /etc/mailman/mm_cfg.py.

To create this list, run:

sudo newlist mailman

You will have to answer a few questions like:

Enter the email of the person running the list: postmaster@example.com
Initial newsletter password: xxx
Hit enter to notify newsletter owner...

Choose the password carefully, as crackers will be able to highjack your mailing list if it is too easy to guess.

The next required step is to add the list aliases to /etc/aliases:

# mailman mailing list
mailman:              "|/var/lib/mailman/mail/mailman post mailman"
mailman-admin:        "|/var/lib/mailman/mail/mailman admin mailman"
mailman-bounces:      "|/var/lib/mailman/mail/mailman bounces mailman"
mailman-confirm:      "|/var/lib/mailman/mail/mailman confirm mailman"
mailman-join:         "|/var/lib/mailman/mail/mailman join mailman"
mailman-leave:        "|/var/lib/mailman/mail/mailman leave mailman"
mailman-owner:        "|/var/lib/mailman/mail/mailman owner mailman"
mailman-request:      "|/var/lib/mailman/mail/mailman request mailman"
mailman-subscribe:    "|/var/lib/mailman/mail/mailman subscribe mailman"
mailman-unsubscribe:  "|/var/lib/mailman/mail/mailman unsubscribe mailman"

In addition to delivering e-mail to the mailing lists, these aliases also allow to subscribe and unsubscribe by writing to special e-mail addresses.

You also need to run the newaliases command, without which there is no e-mail delivery:

sudo newaliases
sudo /etc/init.d/postfix restart
sudo /etc/init.d/mailman restart

Look at the /var/log/mailman/error file for potential issues.

Create regular mailing lists

Regular mailing lists are created in the same way as above: Assuming you want to create a newsletter mailing list. You will need run:

sudo newlist newsletter

Add your new mailing list to /etc/aliases:

# newletter mailing list
newsletter:              "|/var/lib/mailman/mail/mailman post newsletter"
newsletter-admin:        "|/var/lib/mailman/mail/mailman admin newsletter"
newsletter-bounces:      "|/var/lib/mailman/mail/mailman bounces newsletter"
newsletter-confirm:      "|/var/lib/mailman/mail/mailman confirm newsletter"
newsletter-join:         "|/var/lib/mailman/mail/mailman join newsletter"
newsletter-leave:        "|/var/lib/mailman/mail/mailman leave newsletter"
newsletter-owner:        "|/var/lib/mailman/mail/mailman owner newsletter"
newsletter-request:      "|/var/lib/mailman/mail/mailman request newsletter"
newsletter-subscribe:    "|/var/lib/mailman/mail/mailman subscribe newsletter"
newsletter-unsubscribe:  "|/var/lib/mailman/mail/mailman unsubscribe newsletter"

Then, run the usual commands:

sudo newaliases
sudo /etc/init.d/postfix restart
sudo /etc/init.d/mailman restart

Configuring your lists

The easiest way to configure your lists and add members is to open the http://lists.example.com.com/mailman/listinfo URL with a browser.

A few things are also possible from the command line. For example, you can add a member as follows:

echo "alice@example.com" > /tmp/foo
sudo add_members -r /tmp/foo newsletter

Enabling archives

Default file permissions are not completely ready to support mailing list archives:

sudo chown -R root:list /var/lib/mailman/archives
sudo chmod o+rX /var/lib/mailman/archives/private

The second line allows the webserver to access the archives. Note that these settings were forgotten in the official Ubuntu documentation.

Settings for newsletter mailing lists

At Free Electrons, we also use Mailman to deliver our newsletters. Mailman provides recipients with an easy mechanism to subscribe by themselves and unsubscribe whenever they want.

To make it even easier to unsubscribe from a newsletter, Mailman can add a special footer to each recipient, with a custom URL that allows to unsubscribe without having to remember one’s password.

To enable this feature, you have to enable the following line in /etc/mailman/mm_cfg.py:

# Extra options
# Allow to personalize each message
# (useful to provide a password-less unsubscribe link)
OWNERS_CAN_ENABLE_PERSONALIZATION = 1

Restart Mailman (/etc/init.d/mailman restart) and go to the administrative interface for your list. Under Non digest options, you will then be able to set the Should Mailman personalize each non-digest delivery? option to Full Personalization.

Then, you can set a custom footer for each recipient in the Footer added to mail sent to regular list members option. Here is an example:

_______________________________________________
Free Electrons quarterly newsletter
Unsubscribe: %(user_optionsurl)s?password=%(user_password)s
Archives: http://lists.free-electrons.com/pipermail/newsletter/

Beware that sending custom e-mails to each recipient will increase the load on your server. You may not want to do this on mailing lists with great numbers of subscribers.

Useful resources

The below ressources were useful to prepare this HOWTO document:

• Mailman – Ubuntu Community documentation
• Mailman installation manual

Don’t hesitate to ask questions and give feedback by leaving a reply below.

A good part of the Free Electrons team will be in San Francisco (actually, not in San Francisco, but in the Bay Area) from February, 13th to 17th for the Android Builders Summit and the Embedded Linux Conference.

Android Builders Summit 2012

The Android Builders Summit is the second edition of this conference dedicated to Android system development (and not application development). Compared to last year, the conference has been extended to three parallel tracks during two days, as can be seen in the schedule. There are many talks about Android customization, Android internals, Android porting, usage of Android in specific markets (medical devices, vehicle infotainment), etc. A lot of useful talks for developers working at the Android system level.

Embedded Linux Conference 2012

The Embedded Linux Conference is now a well-established conference. Again for this 2012 edition, there will be three parallel tracks during three days. As the schedule shows, there will be talks about many, many topics: performance and optimization, power management, build systems, drivers for various types of devices, multimedia, ARM kernel support and much more.

I will be giving a talk about Buildroot: A Nice, Simple and Efficient Embedded Linux Build System on the second day of the conference. The aim of the talk is to give a status on where Buildroot is, three years after a maintainer was choosen and a big clean up work was started. The project has changed a lot compared to its state three years ago, so I thought it would be nice to make a status on where Buildroot and where it is going.

With my colleagues Grégory Clément and Maxime Ripard, we will also record all the talks from the Embedded Linux Conference in order to put the videos online, freely available, after the conference, as we have done for many past conferences.

We hope to meet you in San Francisco for the Android Builders Summit and the Embedded Linux Conference!

For multiple years, Free Electrons has provided two typical training courses for embedded Linux developers: an Embedded Linux system development course that focuses on the basics for embedded Linux development (bootloader and kernel configuration, compiling and usage, system integration and build systems, cross-compiling, filesystems, application development and debugging, etc.) and an embedded Linux kernel and driver development course that focuses on kernel and driver development (kernel APIs for drivers, character drivers, device model, power management, kernel porting, etc.). In total, we have given dozens of editions of these sessions in multiple locations all around the world. We have kept our commitment to release all the training materials under a free license (the Creative Commons CC-BY-SA license), and they are therefore freely accessible for anyone at http://free-electrons.com/docs/.

We are now announcing a new course, called Android System Development. It is a four day training session that targets engineers who need to develop embedded systems with Google Android.

Through theory and practical labs, the course makes you familiar with compiling and booting Android, with adapting Android to support a new embedded board (assuming that it is already supported by the Linux kernel), and with building a real system through accessing specific hardware, customizing the filesystem and using debugging techniques. See the complete agenda. The training materials for this session will also be made available under the same Creative Commons CC-BY-SA license.

If you are interested in this training session, you can:

• Join the public session organized in Toulouse, France, on June 11-14, 2012. See registration and organization details.
• Order an on-site training session to be held at your location. See registration details.

This training course will be given by our engineer Maxime Ripard who has gained Android experience by working at Archos on Android tablets, by making Android work on multiple TI OMAP3 based platforms and also by participating to the Android Builders Summit conference.

Do not hesitate to contact us for further details about this new training course.

As usual, Free Electrons will again be present at the FOSDEM conference in Brussels, on February, 4th and February 5th. We will of course mostly be attending the Embedded DevRoom, with multiple talks around development in the embedded space.

We will also be giving two talks this year:

• My colleague Maxime Ripard will be giving a talk about IIO, a new subsystem for I/O devices. In short, IIO is a new subsystem in the kernel to write drivers for devices like Analog-to-Digital converters. Maxime has worked on a driver inside the IIO subsystem for the internal ADCs of the AT91 processors from Atmel, and will base his talk mostly on the experience developing this driver. This talk will take place on Saturday, 12:00 AM to 1:00 PM in the Lameere room.
• I will be giving a talk on Using Qt for non-graphical applications. It is a talk that has already been given at the Embedded Linux Conference Europe, but the audience of FOSDEM and ELCE being quite different, we have chosen to propose it for FOSDEM as well, and it got accepted. This talk will take place on Sunday, 1:00 PM to 2:00 PM in the Lameere room.

There are also other talks that are worth noting: a SoC power management talk from Jean Pihet who works on OMAP power management support in the Linux kernel, a talk about OpenCores and OpenRISC, a talk about Safe Upgrade of Embedded Systems by Arnout Vandecappelle, who contributes a lot to Buildroot, and also other talks about OpenWRT, Yocto, licensing issues in Android, the EFL libraries, and more.

We will also be carrying our camcorder to video record those talks. We are trying to see with the FOSDEM organization team if it possible to record the audio directly from the room sound systems in order to provide better audio quality in our videos.

If you happen to be at FOSDEM, we’d be very happy to meet you!

Around each FOSDEM conference and Embedded Linux Conference Europe event, we have been organizing a Buildroot Developer Day for a few years, in order to gather some developers and users of the Buildroot build system, in order to discuss the development of Buildroot, its features, development process, design, and more.

In Prague at the last Embedded Linux Conference Europe in October 2011, we had a very interesting meeting that gathered developers from other build systems (OE-lite, OpenBricks and PXTdist), and we published a report of this meeting.

The next Buildroot Developer Day will take place on Friday, 3rd February, just before the FOSDEM conference, in Brussels. This is the first meeting that will gather such a number of Buildroot developers: Peter Korsgaard (Buildroot maintainer), Arnout Vandecapelle (developer from Essensium/Mind, who has been contributing a lot to Buildroot lately), Thomas De Schampheleire (also a big contributor in the last year or so), Luca Ceresoli, Yann E. Morin (developer of Crosstool-NG), my colleague Maxime Ripard (who contributed package enhancements and improvements of the package infrastructure) and myself.

This meeting is open to all Buildroot developers and users, and will take place in a location easily accessible in the center of Brussels. Do not hesitate to contact me at if you want to take part to this meeting.

The below message has been posted on our English and French newsletters. Don’t hesitate to subscribe to these newsletters if you are interested in getting quarterly news about Free Electrons.

The Free Electrons team wishes you a Happy New Year 2012 and all the best for your professional and personal projects. We are taking this opportunity to give some news about Free Electrons.

In 2011, Free Electrons has:

Worked on multiple development projects for various customers. Amongst the most important ones:

• development of an embedded Linux system and Qt-based application for a RFID/GSM device based on the AT91 ARM processor
• boot time reduction on a MIPS-based point-of-sale system, by improving the embedded Linux system integration
• development of an embedded Linux system for an AT91-based device for the medical field (kernel and bootloader adaptation, system integration, application porting)
• porting of the PREEMPT_RT patch set to the 2.6.32 kernel delivered by Texas Instruments
• developed the driver for the Analog to Digital converters built-in the AT91 processors
• conducted a real-time performance analysis of the PREEMPT_RT and Xenomai solutions on AT91 based processors
• developed an Ubuntu-based embedded system on a BeagleBoard, for image acquisition and analysis with OpenCV
• boot time reduction on an i.MX-based device, with major bootloader modifications
• developed a demonstration system for a racing car control panel on a AT91-based device, with a Qt graphical application

Helped customers solve various embedded Linux related problems, through the support provided by Free Electrons engineers

Contributed to various open-source projects:

• 167 patches to the Buildroot build system
• 6 patches to the Linux kernel, and more are coming with the mainlining of our AT91 ADC driver
• 6 patches to the Barebox bootloader
• 4 patches to the U-Boot bootloader
• 3 patches to the LTT-ng project

Given multiple sessions of our Embedded Linux system development and Linux kernel and driver development courses. The materials of these courses are being constantly updated and are still freely available under a Creative Commons license.

Prepared materials for a new Android system development course. A four days training session to understand the Android system architecture, how to build and customize an Android system for a given hardware platform, how to extend the Android platform to take new hardware devices into account. A first public session will be organized in June in Toulouse.

Switched the hardware platform used in our Embedded Linux system development course from the aging Calao USB-A9263 platform (AT91-based) to the much more powerful IGEPv2 platform from ISEE (OMAP3-based), offering more possibilities to improve our course.

Hired a new engineer, Maxime Ripard, with Android and embedded Linux experience, and created a new office in Toulouse, France.

Moved its headquarters to Orange, France. While we remain reasonably close the Nice area, where we started, we get closer to other parts of France.

Given two presentations at the Embedded Linux Conference Europe in Prague (Using Buildroot for real projects and Qt for non-graphical applications), gave one presentation on boot time reduction at the GENIVI meeting in Dublin, and gave five editions of an embedded Linux introduction seminar in France.

Attended multiple conferences, for which the Free Electrons team also recorded and published videos of the talks:

• FOSDEM 2011
• Embedded Linux Conference 2011
• Android Builders Summit 2011
• Embedded Linux Conference Europe 2011

Participated to the development of the community of Linaro, an engineering organization working on improving Linux on the ARM platform. In addition to making sure that Linaro has all the infrastructure required to nurture a community of developers and users, we also supported Linaro release users on AskLinaro.

In 2012, we expect to:

Work on more development projects in the field of kernel porting, boot time reduction, power management and embedded Linux system integration.

Announce several new training sessions:

• Git training. A two days training session to clearly understand how to use the Git distributed version control system, both for internal projects and for contribution to open-source projects.
• Advanced Buildroot training. A three days training session to get a clear and detailed understanding of the Buildroot embedded Linux build system: how to add new packages, how to customize it to generate the embedded Linux system for a given hardware platform.

As we are currently preparing those courses, we are definitely interested in having feedback. Do not hesitate to contact us with your ideas and needs about those topics.

Switch our Linux kernel and driver development course to an OMAP3-based platform, and expand it to the development of a driver for an I2C-attached device.

Convert our training materials to a text source format (LaTeX), and maintain them in a public git tree, making it easier to contribute to them and to follow changes between between versions.

Participate to multiple conferences. Free Electrons will be present at the FOSDEM in Brussels in February, at the Android Builders Summit and the Embedded Linux Conference in San Francisco in February, and also at the Embedded Linux Conference Europe in Barcelona in October. This participation to conferences allows Free Electrons engineers to remain up-to-date with the latest developments in the embedded Linux area and to create useful contacts in the community.

You can follow Free Electrons news by reading our blog (24 articles in 2011) and by following our quick news on Twitter.

Free Electrons remains available to help you in your embedded Linux projects, either through its development and support services or through its training sessions. Do not hesitate to contact us!

Best regards, and again, Happy New Year 2012!

Gregory, Maria, Maxime, Michael and Thomas – Free Electrons