A few months ago, in May, Bootlin engineer Mylène Josserand presented a talk titled Understanding D-Bus at the Toulouse Embedded Linux and Android meetup.
In this talk, Mylène shared her experience working with D-Bus, especially in conjunction with the OFono and Connman projects, to support modem and 3G connections on embedded Linux systems.
We are now publishing the slides of Mylène’s talk, they are available in PDF format.
Linux 4.7 has been released on Sunday by Linus Torvalds, with numerous new features and improvements that have been described in details on LWN: part 1, part 2 and part 3. KernelNewbies also has an updated page on the 4.7 release. We contributed a total of 222 patches to this release.
Our most significant contributions:
nand_scan_ident() in more drivers, rather than driver-specific code.mtd_ooblayout_ops structure, and use the corresponding helper functions where appropriate. This change will allow a more flexible description of the ECC and OOB layout.rv3029 and m41t80 drivers, including the addition of the support for the RV3049 (the SPI variant of RV3029). See also our previous blog post on the support of Microcrystal’s RTCs/.atmel-hlcdc driver, the DRM/KMS driver for Atmel platformsmv_xor driver to make it 64-bits ready, as the same XOR engine is used on Armada 3700, a Cortex-A53 based SoC. Grégory then enabled the use of the XOR engines on this platform by updating the corresponding Device Tree.Here are in details, the different contributions we made to this release:
Almost exactly one year ago, we announced the availability of our training course on Buildroot. This course received very good feedback, both from our customers, and from the community.
In our effort to continuously improve and update our training materials, we have recently updated our Buildroot training course to Buildroot 2016.05, which was released at the end of May. In addition to adapting our practical labs to use this new Buildroot version, we have also improved the training materials to cover some of the new features that have been added over the last year in Buildroot. The most important changes are:
graph-size functionality, which allows to generate a pie chart of the filesystem size, per package. This is a very nice feature to analyze the size of your root filesystem and see how to reduce it.The updated training materials are available on the training page: agenda (PDF), slides (PDF) and practical labs (PDF).
Contact us if you would like to organize this training session in your company: we are available to deliver it worldwide.
The 4.6 version of the Linux kernel was released last Sunday by Linus Torvalds. As usual, LWN.net had a very nice coverage of this development cycle merge window, highlighting the most significant changes and improvements: part 1, part 2 and part 3. KernelNewbies is now active again, and has a very detailed page about this release.
On a total of 13517 non-merge commits, Bootlin contributed for this release a total of 107 non-merge commits, a number slightly lower than our past contributions for previous kernel releases. That being said, there are still a few interesting contributions in those 107 patches. We are particular happy to see patches from all our eight engineers in this release, including from Mylène Josserand and Romain Perier, who just joined us mid-March! We also already have 194 patches lined-up for the next 4.7 release.
Here are the highlights of our contributions to the 4.6 release:
irq-armada-370-xp interrupt controller driver, to use the new generic MSI infrastructure.pxa3xx_nand driver used on Marvell EBU platforms that prevented using some of the ECC configurations (such as 8 bits BCH ECC on 4 KB pages). He also contributed minor improvements to the generic NAND code.abx80x RTC driver.memset() implementation. The other patch fixes a problem in the generic futex code.In addition, several our of engineers are maintainers of various platforms or subsystems, so they do a lot of work reviewing and merging the contributions from other kernel developers. This effort can be measured by looking at the number of patches on which they Signed-off-by, but for which they are not the author. Here are the number of patches that our engineered Signed-off-by, but for which they were not the author:
Here is the detailed list of our contributions to the 4.6 kernel release:
Bootlin engineer and Allwinner platform maintainer Maxime Ripard has written a long article presenting the Nextthing C.H.I.P platform in issue #18 of French magazine OpenSilicium, dedicated to open source in embedded systems. The C.H.I.P has even been used for the front cover of the magazine!
In this article, Maxime presents the C.H.I.P platform, its history and the choice of the Allwinner SoC. He then details how to set up a developer-friendly environment to use the board, building and flashing from scratch U-Boot, the kernel and a Debian-based root filesystem. Finally, he describes how to use Device Tree overlays to describe additional peripherals connected to the board, with the traditional example of the LED.
In the same issue, OpenSilicium also covers numerous other topics:
Two weeks ago, the entire Bootlin engineering team (9 persons) attended the Embedded Linux Conference in San Diego. We had some really good time there, with lots of interesting talks and useful meetings and discussions.
In addition to attending the event, we also participated by giving 5 different talks on various topics, for which we are publishing the slides:
Boris Brezillon, the new NAND Linux subsystem maintainer, presented on Modernizing the NAND framework: The big picture.
Antoine Ténart presented on Using DT overlays to support the C.H.I.P’s capes.
Maxime Ripard, maintainer of the Allwinner platform support in Linux, presented on Bringing display and 3D to the C.H.I.P computer.
Alexandre Belloni and Thomas Petazzoni presented Buildroot vs. OpenEmbedded/Yocto Project: a four hands discussion.
Thomas Petazzoni presented GNU Autotools: a tutorial.
All the other slides from the conference are available from the event page as well as from eLinux.org Wiki. All conferences have been recorded, and the videos will hopefully be posted soon by the Linux Foundation.
Bootlin engineer Boris Brezillon has been involved in the support for NAND flashes in the Linux kernel for quite some time. He is the author of the NAND driver for the Allwinner ARM processors, did several improvements to the NAND GPMI controller driver, has initiated a significant rework of the NAND subsystem, and is working on supporting MLC NANDs. Boris is also very active on the linux-mtd mailing list by reviewing patches from others, and making suggestions.
For those reasons, Boris was recently appointed by the MTD maintainer Brian Norris as a new maintainer of the NAND subsystem. NAND is considered a sub-subsystem of the MTD subsystem, and as such, Boris will be sending pull requests to Brian, who in turn is sending pull requests to Linus Torvalds. See this commit for the addition of Boris as a NAND maintainer in the MAINTAINERS file. Boris will therefore be in charge of reviewing and merging all the patches touching drivers/mtd/nand/, which consist mainly of NAND drivers. Boris has created a nand/next branch on Github, where he has already merged a number of patches that will be pushed to Brian Norris during the 4.7 merge window.
We are happy to see one of our engineers taking another position as a maintainer in the kernel community. Maxime Ripard was already a co-maintainer of the Allwinner ARM platform support, Alexandre Belloni a co-maintainer of the RTC subsystem and Atmel ARM platform support, Grégory Clement a co-maintainer of the Marvell EBU platform support, and Antoine Ténart a co-maintainer of the Annapurna Labs platform support.
As we announced in a previous blog post, Bootlin CTO Thomas Petazzoni gave a talk at the Collaboration Summit 2016 covering the topic of “Upstreaming hardware support in the Linux kernel: why and how?“.
The slides of the talk are now available in PDF format.
Through this talk, we identified a number of major reasons that should encourage hardware vendors to contribute the support for their hardware to the upstream Linux kernel, and some hints on how to achieve that. Of course, within a 25 minutes time slot, it was not possible to get into the details, but hopefully the general hints we have shared, based on our significant Linux kernel upstreaming experience, have been useful for the audience.
Unfortunately, none of the talks at the Collaboration Summit were recorded, so no video will be available for this talk.
Linus Torvalds just released Linux 4.5, for which the major new features have been described by LWN.net in three articles: part 1, part 2 and part 3. On a total of 12080 commits, Bootlin contributed 121 patches, almost exactly 1% of the total. Due to its large number of contribution by patch number, Bootlin engineer Boris Brezillon appears in the statistics of top-contributors for the 4.5 kernel in the LWN.net statistics article.
This time around, our important contributions were:
The complete list of our contributions:
We are happy to announce that on February 8th 2016 we submitted to the mainline Linux kernel the initial support for Annapurna Labs Alpine v2 Platform-on-Chip based on the 64-bit ARMv8 architecture.
See our patch series:
Annapurna Labs was founded in 2011 in Israel. Annapurna Labs provides 32-bit and 64-bit ARM products including chips and subsystems under the Alpine brand for the home NAS, Gateway and WiFi router equipment, see this page for details. The 32-bit version already has support in the official Linux kernel (see alpine.dtsi), and we have started to add support for the quad core 64-bit version, called Alpine v2, which brings significant performance for the home.
This is our initial contribution and we plan to follow it with additional Alpine v2 functionality in the near future.