At Bootlin, we owe a lot to the Free Software community, and we’re doing our best to give back as much as we can.
One way of doing that is welcoming community contributors in our public training sessions organized in France. We’ve done that multiple times several years back, and this allowed us to meet very interesting people (who even had very valuable experience and points of view to share with the other course participants), while of course giving them extra knowledge that they can use for further contributions.
Here are the next sessions in which we can offer a free seat:
We’ve started to use Mastodon (in addition to Twitter and LinkedIn) to share quick news with you: new blog posts, contributions to Free Software projects, photos at events, etc.
Did you know Mastodon? I’ll like Twitter, but better, decentralized and really free (as in Free Software). I discovered it by attending one of the conferences we sponsor (Capitole du Libre in Toulouse, France) and by following the efforts of Framasoft to provide decentralized Internet services.
Being Free Software and not biased by the need to maximize revenue for its investors
It’s decentralized and therefore controlled by its users. You are free to join an instance that matches your interests and sensibility, but of course you can follow anyone on any other instance. It’s also easy to move to another instance or even host your own one
There are no Retweets but Boosts. Retweets allow to share a post with your own comments to all your followers. This creates flame wars in the best interest of Twitter. Twitter needs its users to spend as much time as possible viewing the content they host (and therefore their promoted content at the same time). Instead, Mastodon only allows to “boost” the visibility of someone else’s post, without allow you to add your own comments. Mastodon has no interest in making you stay as long as possible by creating flame wars. It just lets you focus on the content your are interested in.
In a nutshell, using Mastodon contributes to a better world in which users are in control of their data, interests and time.
Here are details about booting the Beagle Bone Black Wireless board through NFS. I’m writing this here because it doesn’t seem to be documented anywhere else (except in our Linux kernel and driver development course, for which I had to support this feature).
Booting a board on a root filesystem that is a directory on your workstation (development PC) or on a server, shared through the network, is very convenient for development purposes.
For example, you can update kernel modules or programs by recompiling them on your PC, and the target board will immediately “see” the updates. There’s no need to transfer them in some way.
Doing this is quite straightforward on boards that have an Ethernet port, and well documented throughout the Internet (see our instructions). However, things get more complicated with boards that have no such port, such as the Beagle Bone Black Wireless or the Pocket Beagle.
The Beagle Bone Black Wireless board has WiFi support, but booting on NFS directly from the kernel (instead of using an initramfs) is another kind of challenge.
Something easier to use is networking over USB device (also called USB gadget as our operating system is running on the USB device side), which is supported by both Linux and U-Boot.
Note that the below instructions also work on the original Beagle Bone Black, bringing the convenience of not having to use an RJ45 cable. All you need is the USB device cable that you’re using for power supply too.
These instructions should also support the Pocket Beagle board, which is similar, though much simpler.
This part may just work out of the box if the U-Boot version on your board is recent and was built using the default configuration for your board.
If that’s not the case, you can reflash U-Boot on your board using our instructions.
These instructions have been tested on Ubuntu 18.04, but they should be easy to adapt on other GNU/Linux distributions.
To configure your network interface on the workstation side, we need to know the name of the network interface connected to your board.
However, you won’t be able to see the network interface corresponding to the Ethernet over USB device connection yet, because it’s only active when the board turns it on, from U-Boot or from Linux. When this happens, the network interface name will be enx. Given the value we gave to usbnet_hostaddr, it will therefore be enxf8dc7a000001.
Then, instead of configuring the host IP address from NetWork Manager’s graphical interface, let’s do it through its command line interface, which is so much easier to use:
nmcli con add type ethernet ifname enxf8dc7a000001 ip4 192.168.0.1/24
To download the kernel and device tree blob which are also on your PC, let’s install a TFTP server on it:
sudo apt install tftpd-hpa
You can then test the TFTP connection, which is also a way to test that USB networking works. First, put a small text file in /var/lib/tftpboot.
Then, from U-Boot, do:
tftp 0x81000000 textfile.txt
The tftp command should have downloaded the textfile.txt file from your development workstation into the board’s RAM at location 0x81000000. You can verify that the download was successful by dumping the contents of memory:
We are now ready to load and boot a Linux kernel!
These instructions were tested with Linux 4.19
Configuring and cross-compiling the Linux kernel for the board is outside the scope of this article, but again, such information is easy to find (such as in our training slides).
Here, we’re just sharing the Linux kernel configuration settings that are needed for networking over USB device. Since they are not supported by the default configuration file for the omap2plus CPU family (for several reasons that were discussed on the Linux kernel mainling list), it took a bit of time to figure out which ones were needed. Here they are:
Add the below options to support networking over USB device:
CONFIG_USB_MUSB_HDRC=y: Driver for the USB OTG controller
CONFIG_USB_MUSB_GADGET=y: Use the USB OTG controller in device (gadget) mode
Check the dependencies of CONFIG_AM335X_PHY_USB. You need to set CONFIG_NOP_USB_XCEIV=y to be able to set CONFIG_AM335X_PHY_USB=y
Find the ”USB Gadget precomposed configurations” menu and set it to static instead of module so that CONFIG_USB_ETH=y
How did I found out which settings were needed? I had to check the device tree to find the USB device controller. Then, using git grep, I found the driver that was supporting the corresponding compatible string. Then, looking at the Makefile in the driver directory, I found which kernel configuration settings were needed.
When compiling is over, copy the zImage and am335x-boneblack-wireless.dtb files to the TFTP server home directory (/var/lib/tftpboot).
You also need an NFS server on your workstation:
sudo apt install nfs-kernel-server
Then edit the /etc/exports file as root to add the following line, assuming that the IP address of your board will be 192.168.0.100:
Now check the kernel log and make sure an IP address is correctly assigned to your board by Linux. If NFS booting doesn’t work yet, that could be because of NFS server or client issues. If that’s the case, you should find details in the NFS server logs in /var/log/syslog on your PC.
Profile: for this new position, meant to strengthen our small team in Lyon (currently two people), we are looking for someone with already valuable experience and autonomy in embedded Linux and kernel development. The positions that will follow should be open to junior engineers.
Lyon is a beautiful and vibrant city, the second largest urban area in France, which two rivers instead of one! Our office is within 5 minutes of a subway station, and is also easy to access from more residential areas in the south of Lyon.
If you are interested, please send a resume to email@example.com, letting us know about your interests and ideas for the job.
Free Electrons is changing to a new name, in the context of a trademark dispute.
Reasons for changing
On July 25, 2017, the company FREE SAS, a French telecom operator, known as the owner of the free.fr website, filed a complaint before the District Court of Paris against Free Electrons and its founder Michael Opdenacker for infringing upon 3 trademarks which include the word “free” and on FREE SAS’s rights on its domain name and its company name.
In this complaint, FREE SAS asked, among others, the French judges to order Free Electrons and its founder Michael Opdenacker to pay the total sum of 107,000 euros on various grounds, to order Free Electrons to change name, to delete the domain name “free-electrons.com” within 15 days and to cease all use of the sign “FREE ELECTRONS” but also of the term “free” alone or with any other terms in any field in which FREE SAS is active or for any goods and services covered by its prior trademarks.
Michael Opdenacker and Free Electrons’ management consider that these claims are unfounded as both companies were coexisting peacefully since 2005.
The services we offer are different, we target a different audience (professionals instead of individuals), and most of our communication efforts are in English, to reach an international audience. Therefore Michael Opdenacker and Free Electrons’ management believe that there is no risk of confusion between Free Electrons and FREE SAS.
However, FREE SAS has filed in excess of 100 oppositions and District Court actions against trademarks or names containing “free”. In view of the resources needed to fight this case, Free Electrons has decided to change name without waiting for the decision of the District Court.
This will allow us to stay focused on our projects rather than exhausting ourselves fighting a long legal battle.
The new name
Amongst all the new names we considered, “Bootlin” came out as our favorite option. It can’t express all our values but it corresponds to what we’ve been working on since the beginning and hope to continue to do for many years: booting Linux on new hardware.
Of course, “booting” here shouldn’t be limited to getting a first shell prompt on new hardware. It means doing whatever is needed to run Linux by taking the best advantage of software and hardware capabilities.
Same team, same passion
Nothing else changes in the company. We are the same engineers, the same Linux kernel contributors and maintainers (now 6 of us have their names in the Linux MAINTAINERS file), with the same technical skills and appetite for new technical challenges.
More than ever, we remain united by the passion we all share in the company since the beginning: working with hardware and low-level software, working together with the free software community, and sharing the experience with others so that they can at least get the best of what the community offers and hopefully one day become active contributors too. “Get the best of the community” is effectively one of our slogans.
The only thing we’re changing is the name (“Bootlin” instead of “Free Electrons”), the domain name (bootlin.com instead of free-electrons.com) and the logo. The two penguins, our mascots which have been the key identification of Free Electrons for many years will stay the same. Except for the domain name change, all URLs should stay the same, and all e-mail addresses too.
For the moment, we’ve just migrated the mail and main web servers. The other services will be updated progressively.
For practical reasons, the name of the company running Bootlin will remain “Free Electrons” for a few more months. Until then, there won’t be any impact on the way we interact with our customers. We will let our ongoing customers know when the legal name changes.
What about links to free-electrons.com resources, made by community websites but also in mailing lists archives and in public forums? Of course, we redirected the old URLs to the new ones, and will continue to do so as long as we can. However, depending on the outcome of the legal procedure, we may not be able to keep the free-electrons.com domain forever. Therefore, we would be grateful if you could update all your links to our site whenever feasible, to avoid the risk of broken links in the future.