Linaro Engineering Highlights: April 2020 background image

Linaro Engineering Highlights: April 2020

Jon Burcham

Welcome to the April 2020 edition of the Linaro Engineering Highlights. This is a roundup of all of the latest news and developments from last month including:-

  • Linaro’s Contributions to the Linux v5.6 Kernel LTP (Linux Test Project)
  • PSA Level 1 Certification Showcase
  • Linaro Consumer Group (LCG) News
  • OTA article - Industrial Internet Consortium Journal of Innovation
  • Protein Folding on Arm Devices - Helping with COVID-19 Research by Sahaj Sarup

Linaro’s Contributions to the Linux v5.6 Kernel

Mark Orvek, VP Engineering

As reported by LWN, the latest stable Linux Kernel (version 5.6) was released on March 29th. I wanted to highlight five notable Linaro related statistics from the article; you can read the full LWN article at Some 5.6 kernel development statistics:

  • Linaro is the #2 company by number of lines changed and the #6 (known) company by changesets.
  • Two Linaro employees (Arnd Bergmann and Srinivas Kandagatla) are #2 and #7 individual contributors by number of lines changed.
  • Arnd Bergmann is the #6 individual contributor by changesets.
  • Not mentioned in the article but two other key statistics

    • Linus Walleij 7th 1.6% Reviewed-by in 5.6
    • Naresh Kamboju ranked at #10 for reported-by

Most Active 5.6 Employers

By Changesets     By Lines Changed    
Intel 1694 13.4% Intel 78083 11.5%
(Unknown) 904 7.1% Code Aurora Forum 68538 10.1%
AMD 781 6.2% Linaro 59492 8.8%
(None) 778 6.1% AMD 44979 6.6%
SUSE 713 5.6% Red Hat 40553 6.0%
Red Hat 702 5.5% (Unknown) 28591 4.2%
Google 558 4.4% (None) 27387 4.0%
Linaro 503 4.0% (Consultant) 23271 3.4%
Huawei Technologies 483 3.8% Google 20038 3.0%
Facebook 298 2.4% SUSE 19274 2.8%
Mellanox 252 2.0% Facebook 17525 2.6%
Renesas Electronics 247 2.0% Texas Instruments 16561 2.4%
IBM 232 1.8% Mellanox 14977 2.2%
Arm 231 1.8% Linux Foundation 12289 1.8%
Code Aurora Forum 222 1.8% Marvell 11678 1.7%
(Consultant) 216 1.7% Realtek 10968 1.6%
Texas Instruments 213 1.7% Collabora 9491 1.4%
NXP Semiconductors 210 1.7% NXP Semiconductors 8689 1.3%
Oracle 147 1.2% Solarflare 8670 1.3%
Broadcom 143 1.2% IBM communications 8586 1.3%

Most Active 5.6 Developers

By Changesets     By Lines Changed    
Takashi Iwai 406 3.2-% Kalle Valo 48483 7.2%
Chris Wilson 306 2.4% Arnd Bergmann 29415 4.3%
Sean Christopherson 143 1.1% Jason A. Donenfeld 18664 2.8%
Jérôme Pouiller 125 1.0% Ben Skeggs 13471 2.0%
Eric Biggers 122 1.0% Greg Kroah-Hartman 11931 1.8%
Arnd Bergmann 114 0.9% Chris Wilson 10615 1.6%
Zheng Bin 110 0.9% Srinivas Kandagatla 8739 1.3%
Geert Uytterhoeven 103 0.9% Alex Maftei 8581 1.3%
Greg Kroah-Hartman 103 0.8% Maxime Ripard 7521 1.1%
Masahiro Yamada 94 0.7% Peter Ujfalusi 6970 1.0%
Colin Ian King 92 0.7% Tony Lindgren 6320 0.9%
Ben Skeggs 91 0.7% Helen Koike 5789 0.9%
Ville Syrjälä 90 0.7% Takashi Iwai 5622 0.8%
Andy Shevchenko 88 0.7% Shuming Fan 5604 0.8%
Russel King 88 0.7% Michal Kalderon 5445 0.8%
Alex Deucher 86 0.7% Sricharan R 5065 0.7%
Krzysztof Kozlowski 82 0.6% Andrii Nakryiko 4857 0.7%
Thomas Zimmermann 80 0.6% Roman Li 4852 0.7%
Jens Axboe 77 0.6% Thierry Reding 4845 0.7%
Jani Nikula 74 0.6% Sunil Goutham 4762 0.7%

Congratulations to Arnd, Srinivas, Linua and Naresh for being top contributors to the 5.6 kernel and a thank you to all those who keep Linaro in the top ten Linux Kernel contributors every release.

LTP (Linux Test Project)


Linaro had been asked by the Members to work on the Linux Test Project (aka LTP) and enhance it to cover all the syscalls in the Linux Kernel. With best effort staffing, work had been progressing slowly. In January, Viresh Kumar (KWG) was able to take up this work and put in a sustained effort, quickly closing the gap and adding support for the following syscalls:

  • pidfd_open Io_pgetevents
  • Fsopen
  • Fsconfig
  • Fsmount
  • Fspick
  • Open_tree
  • Move_mount
  • Clone3
  • Openat2

All of the above have been merged, while work is in progress for three syscalls related to io_uring supported by an ARM member engineer. In addition, twenty new syscalls have been added to the task, all related to the time64 variants and these are now underway. Further information is available in KWG-326.

PSA Level 1 Certification Showcase

Linaro IoT and Embedded (LITE)

Kevin Townsend, LITE Senior Engineer, completed certification of the TF-M integration with Zephyr. This effort was featured on the PSA Certified website.


With the latest updates in TF-M and PSA, Kevin is working on a recertification with a Linaro Member board. We will post the news when that recertification is completed.

Linaro Consumer Group (LCG) News

Tom Gall, Director LCG

This month the Linaro Consumer Group team released two blog posts highlighting work going on within the segment group and in coordination with our Member companies.


The first blog discusses the current state of HiKey and HiKey960 boards and their usefulness as Android Open Source Project (AOSP) development boards. John Stultz talks about the current state of support and how these devices are useful, valued members of the Android development ecosystem.

The second blog post is about how the effort enabling the SDM845 on the Dragonboard 845 bloomed into making possible mainline linux kernel development on a consumer form factor Android devices like the Pixel 3 and Poco F1. The efforts also highlight the effectiveness of the Android-5.4 GKI kernel and its ability to boot multiple devices from the same binary.

AOSP on Pixel3/PocoF1 (Running AOSP with mainline kernels on form factor devices)

OTA article - Industrial Internet Consortium Journal of Innovation

Francois Ozog, Director LEDGE


LEDGE has a leadership role in Over-The-Air (OTA) Special Interest Group in the Industrial Internet Consortium and was proposed to author an article on OTA and Intelligent Transport Systems (ITS). It was published on March 27th in the Journal of Innovation web page after circulation for validation amongst LEDGE members.

The article exposes the challenges of OTA for current and future systems. OTA can have a significant impact in ITS. For instance, there can be an increase in peak power by 5% (resulting in 0-60mph in 2.9s instead of 3.2s). But it comes with many complexities not experienced in the mobile phone market. So many aspects of OTA in ITS need co-innovation and some form of standardization highlighted in the article.

Protein Folding on Arm Devices | Helping with COVID-19

Research by Sahaj Sarup


Recently I have been spending my spare cycles, along with a few other friends from the Arm Ecosystem, to get the power and efficiency of the aarch64 ISA in the hands of researchers and institutes that have been working tirelessly to make sense of the COVID-19 pandemic.