Bootlin at the Libre Software Meeting

In a previous post, we detailed all the talks of the Embedded Systems and Open Hardware track of the Libre Software Meeting, taking place in Geneva in early July.

Bootlin will have a quite important presence at this event, with three talks and one tutorial given by Bootlin engineers. You’ll find below the descriptions of the talks given by Bootlin. Both my colleague Maxime Ripard and myself will be present at Libre Software Meeting, and we will be happy to meet you there to discuss Embedded Linux and Android topics!

A look through the Android Stack

Android has established itself in the past years as a major player in the mobile market, outperforming any other mobile systems.

To do so, Google relied both on well established open-source components, such as the Linux Kernel, and munching them together in a brand new userspace environment. This talk will detail the most important components of Android userspace and the interactions between them that allow developers to face a consistent API for their applications.

This talk will be given on Tuesday 9th July 2012, at 14:00, by Maxime Ripard, embedded Linux and Android engineer at Bootlin. Maxime is also teaching our newest training course on Android system development.

Buildroot: a nice, simple and efficient embedded Linux build system

Started in late 2001 by uClibc developers, Buildroot has grown over its 10 years history from a testing tool for the uClibc C library to a complete, vendor-neutral, embedded Linux build system. Until early 2009, the project was mostly unmaintained and the quality slowly decreased, frustrating many Buildroot users. Fortunately, since early 2009, Peter Korsgaard took over the maintainership of Buildroot, and the project has considerably evolved since then: stable releases are published every three months, the user and developer community has grown significantly, the existing features have been cleaned up, many other new features have been added, the project is no longer uClibc-specific and the quality has been vastly improved. Buildroot now offers a nice, simple and efficient mechanism to build small to medium sized embedded Linux systems, such as the ones found in many industrial systems or highly dedicated systems. Many users are amazed about how easy it is to get started with Buildroot, especially compared to other build systems. This presentation will show how Buildroot can be used to build embedded Linux systems, highlighting the new features and improvements made over the last few years, and detailing how the simplicity of Buildroot allows you to focus on developing the applications for your system. A quick overview of the future Buildroot developments will also be provided.

This talk will take place on Wednesday 10th July at 17:00 and will be given by Thomas Petazzoni, embedded Linux engineer at Bootlin, and long time Buildroot contributor.

Linux kernel on ARM: consolidation work

In Spring 2011, Linus Torvalds asked the ARM Linux maintainers to clean up the contents of arch/arm/ in the Linux kernel code by doing more consolidation between ARM sub-architectures.

More than a year later, a lot of work has been accomplished in this area, especially thanks to the introduction of the device tree for the ARM architecture, the pinctrl subsystem and the clock framework into the Linux kernel.

Through this talk, we will present the challenges the ARM architecture creates in terms of Linux kernel support, and then describe from a technical point of view how the device tree, the pinctrl subsystem and the clock subsystem work and how they can improve the consolidation between different ARM sub-architectures.

The talk will be designed to be accessible to an audience having only a moderate knowledge of kernel programming and internals, and will therefore provide enough context for such audience to understand the issues that those different mechanisms are striving to solve.

This talk will take place on Thursday 11th July at 10:00 and will be given by Thomas Petazzoni, embedded Linux engineer at Bootlin.

Tutorial on using Buildroot, a nice, simple and efficient embedded Linux build system

Started in late 2001 by uClibc developers, Buildroot has grown over its 10 years history from a testing tool for the uClibc C library to a complete, vendor-neutral, embedded Linux build system. Until early 2009, the project was mostly unmaintained and the quality slowly decreased, frustrating many Buildroot users. Fortunately, since early 2009, Peter Korsgaard took over the maintainership of Buildroot, and the project has considerably evolved since then: stable releases are published every three months, the user and developer community has grown significantly, the existing features have been cleaned up, many other new features have been added, the project is no longer uClibc-specific and the quality has been vastly improved. Buildroot now offers a nice, simple and efficient mechanism to build small to medium sized embedded Linux systems, such as the ones found in many industrial systems or highly dedicated systems. Many users are amazed about how easy it is to get started with Buildroot, especially compared to other build systems.

This workshop follows the Buildroot presentation proposed in the same topic. During one half-day participants will be introduced on how to efficiently use Buildroot for their own projects:

  • Basic usage of Buildroot: generate the first system, boot it on a hardware platform
  • Add packages to Buildroot
  • Customize Buildroot for real-life projects: how to integrate project specific patches, configuration and customization

Participants are invited to come with their own laptop, installed with a sufficiently recent GNU/Linux distribution. Participants are recommended to attend the Buildroot talk by the same speaker before attending the workshop, as the talk will give an overall introduction on Buildroot.

This tutorial will take place on Thursday 11th July from 14:00 to 17:00 and will be given by Thomas Petazzoni, embedded Linux engineer at Bootlin, and long time Buildroot contributor.

Embedded topics at the Libre Software Meeting, Geneva, July 9-11

Libre Software Meeting, Geneva
Libre Software Meeting, Geneva

The Libre Software Meeting is a community-driven free software event that exists since 2000, composed of talks and workshops. Its 2012 edition will take place from July 7th to July 12th in Geneva, Switzerland.

In the context of this conference, I was responsible with Florian Fainelli from the OpenWRT project to organize the Embedded systems and open hardware track. This track will offer an interesting selection of talks related to embedded topics, concentrated between July 9th and July 11th:

Geneva
Geneva

In the Operating Systems track, some other conferences might be of interested to Embedded Linux developers as well:

The entrace to the Libre Software Meeting is free, so don’t hesitate to book your train or flight tickets, and join us at this event!

Linux kernel engineer job in Nice

Penguin worksBootlin is looking for a embedded Linux and kernel engineer in the area of Nice in France (on the French Riviera). The contract will be home based, but will also involve working at customer locations in the same area, possibly for long periods of time.

A detailed job description is available on our careers page.

For this particular job opening, we absolutely need someone with prior experience with kernel and driver development, and contributions to the official Linux kernel sources will be a strong advantage. This is because a customer of ours is looking for an engineer to develop new drivers and port the Linux kernel to pre-silicon and silicon platforms.

Once we find a candidate with the expected skills and profile, and once the customer agrees to contract this person for this initial project, the engineer will be hired by Bootlin under a permanent contract, and will work on the customer site for at least 6 months.

Once the initial assignment is over, our engineer will continue to work on projects for other Bootlin customers, and will also give embedded Linux and kernel training sessions to customers throughout the world.

Note that this position is open to people who do not speak French, but are ready to settle in the French Riviera and to be hired through a French contract.

If you are interested in this position, see our job description for details about how to apply.

Embedded Linux Conference 2012 videos

The 2012 edition of the Embedded Linux Conference took place on February 15-17th 2012 at Redwood Shores near San Francisco in California. Three engineers of Bootlin attended this conference, and we reported every day our impressions about the talks, see our blog posts for day 1, day 2 and day 3. We have now taken the time to encode all the videos we have recorded during this event, and are proud to distribute them today.

It is worth noting that for the first time, the Linux Foundation was also recording videos of the talks, the Linux Foundation videos are available from video.linux.com, and we included links to these videos below for the different talks.

We hope that those of you who couldn’t attend the conference will enjoy those videos, with many great talks on technical embedded Linux topics.

Jon CorbetVideo capture
Editor at LWN.net
The Kernel Report
Slides
Linux Foundation video
Bootlin video (53 minutes):
full HD (525M), 450×800 (154M)

Loïc PallardyVideo capture
Saving the Power Consumption of the Unused Memory
Slides
Bootlin video (46 minutes):
full HD (378M), 450×800 (125M)

Bernhard RosenkränzerVideo capture
Linaro
What Android and Embedded Linux Can Learn From Each Other
Slides
Linux Foundation video
Bootlin video (40 minutes):
full HD (370M), 450×800 (129M)

Ricardo Salveti de AraujoVideo capture
Linaro
Ubuntu on ARM: Improvements and Optimizations Done By Linaro
Slides
Linux Foundation video
Bootlin video (46 minutes):
full HD (301M), 450×800 (140M)

Zach PfefferVideo capture
Linaro
Binary Blobs Attack
Slides
Linux Foundation video
Bootlin video (50 minutes):
full HD (486M), 450×800 (157M)

Hisao MunakataVideo capture
Renesas Electronics
Close Encounters of the Upstream Resource
Slides
Linux Foundation video
Bootlin video (37 minutes):
full HD (394M), 450×800 (121M)

Daniel HurshVideo capture
IBM
Open Source Automated Test Framework
Slides
Bootlin video (45 minutes):
full HD (303M), 450×800 (132M)

Saul WoldVideo capture
Intel
The Yocto Project Overview and Update
Slides
Linux Foundation video
Bootlin video (54 minutes):
full HD (543M), 450×800 (171M)

Sean HudsonVideo capture
Mentor Graphics, Inc.
Embedded Linux Pitfalls
Slides
Bootlin video (51 minutes):
full HD (483M), 450×800 (176M)

Vincent GuittotVideo capture
Linaro
Comparing Power Saving Techniques For Multicore ARM Platforms
Slides
Linux Foundation video
Bootlin video (57 minutes):
full HD (307M), 450×800 (154M)

Tim BirdVideo capture
Sony Network Entertainment
Status of Embedded Linux
Slides
Linux Foundation video
Bootlin video (49 minutes):
full HD (492M), 450×800 (159M)

Bruce AshfieldVideo capture
Wind River
A View From the Trenches: Embedded Functionality and How It Impacts Multi-Arch Kernel Maintenance
Slides
Bootlin video (54 minutes):
full HD (741M), 450×800 (222M)

R DurgadossVideo capture
Intel
PeakCurrent Management in x86-Based Smartphones
Slides
Linux Foundation video
Bootlin video (50 minutes):
full HD (296M), 450×800 (141M)

Matt PorterVideo capture
Texas Instruments
Passing Time With SPI Framebuffer Driver
Slides

Bootlin video (54 minutes):
full HD (565M), 450×800 (172M)

WookeyVideo capture
Linaro
Multiarch and Why You Should Care: Running, Installing and Crossbuilding With Multiple Architectures
Slides
Bootlin video (42 minutes):
full HD (453M), 450×800 (143M)

Amit Daniel KachhapVideo capture
Linaro/Samsung
A New Simplified Thermal Framework For ARM Platforms
Slides
Linux Foundation video
Bootlin video (41 minutes):
full HD (226M), 450×800 (115M)

Tsugikazu ShibataVideo capture
NEC
On The Road: To Provide the Long-Term Stable Linux For The Industry
Slides
Linux Foundation video
Bootlin video (32 minutes):
full HD (304M), 450×800 (95M)

Thomas P. AbrahamVideo capture
Samsung Electronics
Experiences With Device Tree Support Development For ARM-Based SOC’s
Slides
Bootlin video (44 minutes):
full HD (509M), 450×800 (155M)

Paul E. McKenneyVideo capture
IBM
Making RCU Safe For Battery-Powered Devices
Slides
Linux Foundation video
Bootlin video (52 minutes):
full HD (506M), 450×800 (186M)

Mike AndersonVideo capture
Chief Technology Officer at The PTR Group
The Internet of Things
Slides
Linux Foundation video
Bootlin video (50 minutes):
full HD (580M), 450×800 (186M)

Thomas PetazzoniVideo capture
Bootlin
Buildroot: A Nice, Simple, and Efficient Embedded Linux Build System
Slides
Linux Foundation video
Bootlin video (56 minutes):
full HD (594M), 450×800 (182M)

Steven RostedtVideo capture
Red Hat
Automated Testing with ktest.pl (Embedded Edition)
Slides
Linux Foundation video
Bootlin video (102 minutes):
full HD (1,2G), 450×800 (354M)

David VomLehnVideo capture
Cisco
Intricacies of a MIPS Stack Backtrace Implementation
Slides
Linux Foundation video
Bootlin video (52 minutes):
full HD (345M), 450×800 (153M)

Edward HerveyVideo capture
Collabora
GStreamer 1.0: No Longer Compromise Flexibility For Performance
Slides
Linux Foundation video
Bootlin video (49 minutes):
full HD (540M), 450×800 (174M)

Tim BirdVideo capture
Sony Network Entertainment
Embedded-Appropriate Crash Handling in Linux
Slides
Linux Foundation video
Bootlin video (49 minutes):
full HD (292M), 450×800 (142M)

Arnd BergmannVideo capture
Linaro
ARM Subarchitecture Status
Slides
Linux Foundation video
Bootlin video (49 minutes):
full HD (416M), 450×800 (140M)

Mark GisiVideo capture
Wind River Systems
The Power of SPDX – Sharing Critical Licensing Information Within a Linux Device Supply Chain
Linux Foundation video
Bootlin video (49 minutes):
full HD (498M), 450×800 (164M)

Yoshitake KobayashiVideo capture
Toshiba
Ineffective and Effective Ways To Find Out Latency Bottlenecks With Ftrace
Slides
Linux Foundation video
Bootlin video (37 minutes):
full HD (251M), 450×800 (108M)

Ohad Ben-CohenVideo capture
Wizery / Texas Instruments
Using virtio to Talk With Remote Processors
Slides
Linux Foundation video
Bootlin video (54 minutes):
full HD (582M), 450×800 (182M)

Elizabeth FlanaganVideo capture
Intel
Embedded License Compliance Patterns and Antipatterns
Linux Foundation video
Bootlin video (44 minutes):
full HD (391M), 450×800 (144M)

David AndersVideo capture
Texas Instruments
Board Bringup: LCD and Display Interfaces
Slides
Linux Foundation video
Bootlin video (40 minutes):
full HD (207M), 450×800 (113M)

Rob ClarkVideo capture
Texas Instruments
DMA Buffer Sharing: An Introduction
Slides
Linux Foundation video
Bootlin video (35 minutes):
full HD (306M), 450×800 (100M)

Ken ToughVideo capture
Intrinsyc
Linux on eMMC: Optimizing For Performance
Slides
Linux Foundation video
Bootlin video (52 minutes):
full HD (468M), 450×800 (165M)

Paul LarsonVideo capture
Linaro
LAVA Project Update
Slides
Linux Foundation video
Bootlin video (52 minutes):
full HD (366M), 450×800 (159M)

Frank RowandVideo capture
Sony Network Entertainment
Real Time (BoFs)
Slides
Bootlin video (77 minutes):
full HD (924M), 450×800 (288M)

Mike TurquetteVideo capture
Texas Instruments
Common Clock Framework (BoFs)
Slides
Bootlin video (53 minutes):
full HD (333M), 450×800 (148M)

Hunyue YauVideo capture
HY Research LLC
Userland Tools and Techniques For Linux Board Bring-Up and Systems Integration
Slides
Linux Foundation video
Bootlin video (51 minutes):
full HD (407M), 450×800 (136M)

Matt WeberVideo capture
Rockwell Collins Inc.
Optimizing the Embedded Platform Using OpenCV
Slides
Linux Foundation video
Bootlin video (37 minutes):
full HD (388M), 450×800 (125M)

Greg UngererVideo capture
McAfee
M68K: Life in the Old Architecture
Slides
Linux Foundation video
Bootlin video (46 minutes):
full HD (452M), 450×800 (166M)

Gary BissonVideo capture
Adeneo Embedded
Useful USB Gadgets on Linux
Slides
Linux Foundation video
Bootlin video (43 minutes):
full HD (402M), 450×800 (129M)

Jason KridnerVideo capture
Texas Instruments
GUIs: Coming To Uncommon Goods Near You
Slides
Linux Foundation video
Bootlin video (52 minutes):
full HD (476M), 450×800 (166M)

Mike AndersonVideo capture
The PTR Group
Adapting Your Network Code For IPv6 Support
Slides
Linux Foundation video
Bootlin video (63 minutes):
full HD (485M), 450×800 (216M)

Koen KooiVideo capture
The Angstrom Distribution
Producing the Beaglebone and Supporting It
Linux Foundation video
Bootlin video (42 minutes):
full HD (398M), 450×800 (126M)

Danny BennettVideo capture
basysKom GmbH
HTML5 in a Plasma-Active World
Slides
Linux Foundation video
Bootlin video (34 minutes):
full HD (258M), 450×800 (75M)

Marcin MielczarczykVideo capture
Tieto
Getting the First Open Source GSM Stack in Linux
Slides
Linux Foundation video
Bootlin video (54 minutes):
full HD (439M), 450×800 (178M)

Pierre TardyVideo capture
Intel
PyTimechart Practical
Slides
Linux Foundation video
Bootlin video (32 minutes):
full HD (260M), 450×800 (86M)

Linus WalleijVideo capture
ST-Ericsson
Pin Control Subsystem Overview
Slides
Linux Foundation video
Bootlin video (60 minutes):
full HD (638M), 450×800 (200M)

Khem RajVideo capture
OpenEmbedded Project
OpenEmbedded – A Layered Approach
Slides
Linux Foundation video
Bootlin video (39 minutes):
full HD (227M), 450×800 (108M)

Lucas De MarchiVideo capture
ProFUSION Embedded Systems
Managing Kernel Modules With kmod
Slides
Linux Foundation video
Bootlin video (46 minutes):
full HD (443M), 450×800 (140M)

Jean PihetVideo capture
NewOldBits
A New Model for the System and Devices Latency
Slides
Bootlin video (49 minutes):
full HD (431M), 450×800 (146M)

Embedded Linux Conference Europe 2011 videos

One week after the end of the Embedded Linux Conference Europe 2011, we are pleased to release the videos of all talks that took place during this event. We would like to thank the Linux Foundation for allowing us to record those talks and to share freely the resulting videos on-line, and also thank the Clarion Congress Hotel technical staff for helping us with technical details related to video recording.

Below, you’ll find 51 videos, in both a 1920×1080 HD format and a reduced 800×450 format. In total, it represents 28 GB of video, for a duration of 2214 minutes, that is more of 36 hours of video. We hope that you will enjoy those videos and that these will be useful to those who couldn’t attend the conference.

Jim ZemlinVideo capture
Executive Director of The Linux Foundation
Imagine a World Without Linux
Video (24 minutes):
full HD (220M), 450×800 (76M)

Linus Torvalds, Alan Cox, Thomas Gleixner, Paul McKenneyVideo capture
moderated by Lennart Poettering
Kernel Developer Panel
Video (55 minutes):
full HD (622M), 450×800 (191M)

Zach PfefferVideo capture
Linaro
Linaro’s Android Platform
Video (45 minutes):
full HD (604M), 450×800 (164M)

Thomas GleixnerVideo capture
Linutronix
State of PREEMPT_RT
Video (46 minutes):
full HD (374M), 450×800 (147M)

Jessica ZhangVideo capture
Intel
The Yocto Project Eclipse plug-in: An effective IDE environment for both Embedded Application and System developers
Video (45 minutes):
full HD (431M), 450×800 (118M)

Satoru UedaVideo capture
Sony Corporation / Japan OSS Promotion Forum
Contributing to the Community? Does your Manager Support You?
Video (42 minutes):
full HD (556M), 450×800 (140M)

Benjamin ZoresVideo capture
Alcatel-Lucent
Embedded Linux Optimization Techniques: How Not To Be Slow
Slides
Video (44 minutes):
full HD (328M), 450×800 (125M)

Ohad Ben-CohenVideo capture
Texas Instruments
Remote Processor Messaging
Slides
Video (48 minutes):
full HD (433M), 450×800 (131M)

Jeff Osier-MixonVideo capture
Intel
Collaborative Initiatives in Embedded Linux
Video (26 minutes):
full HD (266M), 450×800 (73M)

Karim YaghmourVideo capture
Opersys Inc.
Leveraging Android’s Linux Heritage
Video (51 minutes):
full HD (419M), 450×800 (168M)

Pierre TardyVideo capture
Intel
Using pytimechart For Real World Analysis
Slides
Video (51 minutes):
full HD (495M), 450×800 (132M)

Arnd BergmannVideo capture
Linaro
Optimizations for Cheap Flash Media
Video (44 minutes):
full HD (524M), 450×800 (146M)

Vitaly WoolVideo capture
Sony Ericsson
Saving Power with Wi-Fi: How to Prolong Your Battery Life and Still Stay Connected
Slides
Video (50 minutes):
full HD (371M), 450×800 (143M)

David StewartVideo capture
Intel
Developing Embedded Linux Devices Using the Yocto Project and What’s new in 1.1
Slides
Video (47 minutes):
full HD (370M), 450×800 (124M)

Tetsuyuki KobayashiVideo capture
Kyoto Micro Computer
Android is NOT Just “Java on Linux”
Slides
Video (37 minutes):
full HD (542M), 450×800 (129M)

Thomas PetazzoniVideo capture
Bootlin
Using Buildroot For a Real Project
Slides
Video (55 minutes):
full HD (408M), 450×800 (156M)

Tim BirdVideo capture
Sony Network Entertainment
Status of Embedded Linux BoFs
Slides
Video (60 minutes):
full HD (877M), 450×800 (213M)

Lauro Ramos Venancio and Samuel OrtizVideo capture
Instituto Nokia de Tecnologia, Intel
The Linux NFC Subsystem
Slides
Video (31 minutes):
full HD (229M), 450×800 (87M)

David AndersVideo capture
Texas Instruments
Board Bringup: LCD and Display Interfaces
Slides
Video (39 minutes):
full HD (242M), 450×800 (98M)

Antti AumoVideo capture
President of Global Solutions at Ixonos
Re-Defining the Cloud Phone
Video (32 minutes):
full HD (360M), 450×800 (108M)

Dirk HohndelVideo capture
Chief Linux and Open Source Technologist at Intel
Reflection on 20 Years of Linux
Video (30 minutes):
full HD (235M), 450×800 (92M)

Grant LikelyVideo capture
Secret Lab
Device Tree Status Report
Video (51 minutes):
full HD (775M), 450×800 (178M)

Laurent PinchartVideo capture
Ideas on Board
Success Story of the Open-Source Camera Stack: The Nokia N9 Case
Slides
Video (48 minutes):
full HD (308M), 450×800 (120M)

Avinash Mahadeva and Vishwanth SripathyVideo capture
Texas Instuments
SOC Power Management – Debugging and Optimization Techniques
Video (41 minutes):
full HD (288M), 450×800 (108M)

Rafael J. WysockiVideo capture
Faculty of Physics, U. Warsaw / SUSE Labs
Power Management Using PM Domains on SH7372
Slides
Video (46 minutes):
full HD (692M), 450×800 (157M)

Sascha HauerVideo capture
Pengutronix e.K.
A Generic Clock Framework in the Kernel: Why We Need It and Why We Still Don’t Have It
Video (45 minutes):
full HD (345M), 450×800 (134M)

Ruud DerwigVideo capture
Synopsys
Android Platform Optimizations
Slides
Video (43 minutes):
full HD (266M), 450×800 (105M)

Inki DaeVideo capture
Samsung Electronics
DRM Driver Development For Embedded Systems
Slides
Video (22 minutes):
full HD (367M), 450×800 (91M)

Lorenzo PieralisiVideo capture
ARM Ltd.
Consolidating Linux Power Management on ARM Multiprocessor Systems
Slides
Video (46 minutes):
full HD (283M), 450×800 (113M)

Thomas PetazzoniVideo capture
Bootlin
Using Qt For Non-Graphical Applications
Slides
Video (49 minutes):
full HD (340M), 450×800 (124M)

Marek Szyprowski and Kyungmin ParkVideo capture
Samsung Electronics
ARM DMA-Mapping Framework Redesign and IOMMU Integration
Slides
Video (49 minutes):
full HD (790M), 450×800 (195M)

Keerthyd Jagadeesh and Vishwanath SripathyVideo capture
Texas Instruments
Thermal Framework for ARM based SOCs
Video (42 minutes):
full HD (316M), 450×800 (113M)

Marc TitingerVideo capture
ST Microelectronics
Efficient JTAG-Based Linux Kernel Debugging
Slides
Video (57 minutes):
full HD (382M), 450×800 (141M)

Tsugikazu ShibataVideo capture
NEC and Linux Foundation Board Member
Toward the Long Term Stable Kernel tree for The Embedded Industry
Video (32 minutes):
full HD (606M), 450×800 (145M)

Lisko LappalainenVideo capture
MontaVista Software
Secure Virtualization in Automotive
Video (40 minutes):
full HD (301M), 450×800 (116M)

Jeff Osier-MixonVideo capture
Intel
Yocto Project Community BoFs
Video (60 minutes):
full HD (451M), 450×800 (167M)

Jon CorbetVideo capture
Editor at LWN.net
The Kernel Report: 20th Anniversary Edition
Video (28 minutes):
full HD (218M), 450×800 (88M)

Wim CoekaertsVideo capture
Senior Vice President, Linux and Virtualization Engineering at Oracle
Engineered Systems With Linux
Video (21 minutes):
full HD (175M), 450×800 (68M)

Andrea GalloVideo capture
ST-Ericsson
ARM Linux Kernel Alignment and Benefits For Snowball
Slides
Video (47 minutes):
full HD (394M), 450×800 (133M)

Liam Girdwood and Peter UjfalusiVideo capture
Texas Instruments
Smart Audio: Next-Generation ASoC For Smart Phones
Video (50 minutes):
full HD (367M), 450×800 (124M)

Pawel MollVideo capture
ARM Ltd.
Linux on Non-Existing SoCs
Video (52 minutes):
full HD (483M), 450×800 (143M)

Koen KooiVideo capture
The Angstrom Distribution
Integrating systemd: Booting Userspace in Less Than 1 Second
Slides
Video (44 minutes):
full HD (343M), 450×800 (125M)

Sylvain Leroy and Philippe ThierryVideo capture
Grsecurity in Embedded Linux Used in Android Operating System
Slides
Video (40 minutes):
full HD (384M), 450×800 (110M)

MyungJoo HamVideo capture
Samsung Electronics
Charger Manager: Aggregating Chargers, Fuel-Gauges and Batteries
Slides
Video (33 minutes):
full HD (434M), 450×800 (109M)

Arnd BergmannVideo capture
Linaro
News From the ARM Architecture
Video (49 minutes):
full HD (421M), 450×800 (150M)

Frank RowandVideo capture
Sony Network Entertainment
How Linux PREEMPT_RT Works
Slides
Video (45 minutes):
full HD (378M), 450×800 (135M)

Catalin MarinasVideo capture
ARM Ltd.
Linux Support for the ARM Large Physical Address Extensions
Slides
Video (52 minutes):
full HD (594M), 450×800 (170M)

Jim HuangVideo capture
0xlab
Build Community Android Distribution and Ensure the Quality
Video (44 minutes):
full HD (472M), 450×800 (143M)

Till JaegerVideo capture
JBB Rechtsanwälte
The Case AVM v. Cybits: The GPL and Embedded Systems
Video (42 minutes):
full HD (362M), 450×800 (124M)

Darren HartVideo capture
Intel
Tuning Linux For Embedded Systems: When Less is More
Slides
Video (45 minutes):
full HD (482M), 450×800 (135M)

Wolfram SangVideo capture
Pengutronix e.K.
Developer’s Diary: It’s About Time
Video (49 minutes):
full HD (482M), 450×800 (141M)

Embedded Linux training: switch to the IGEPv2 board

Since early 2009, our training sessions have been using the USB-A9263 board from Calao Systems as the hardware platform for the practical labs. However, this AT91-based platform was getting older, and we therefore started the process of switching our training sessions to a new hardware platform, the IGEPv2 board from ISEE.

IGEPv2 board
IGEPv2 board

The IGEPv2 platform is very similar to the popular BeagleBoard and BeagleBoard-XM platforms, and has the following technical characteristics :

  • TI DM3730, which is the latest OMAP3 processor from Texas Instruments, clocked at 1 Ghz, and including a DSP for signal processing, an IVA block for audio/video decoding and the PowerVR SGX for 3D/OpenGL. This processor offers far more possibilities than the AT91 one, especially for multimedia applications.
  • 512 MB of RAM and 512 MB of OneNAND flash.
  • Integrated Ethernet connector, Wifi and Bluetooth connectivity.
  • One USB OTG port and one USB host port.
  • A microSD connector.
  • A DVI-D connector (HDMI), stereo input and ouput
  • RS232 connector
  • Multiple expansion ports to access LCD, camera, I2C, SPI, JTAG, etc. signals

Compared to the BeagleBoard-XM, this board has the following advantages:

  • it has a OneNAND Flash device, which allows us to demonstrate and practice the usage of MTD and Linux flash-specific filesystems such as JFFS2 and UBIFS in our training sessions. Even though block-based storage such as SD and eMMC is more and more popular in consumer-electronic devices, usage of raw NAND flash is still very common in industrial applications, and we therefore wanted to keep presenting those devices and their usage in embedded Linux
  • ISEE, the company manufacturing the IGEPv2, is located in Spain, which makes it easier for us to regularly order boards from them, since we are also located in Europe
  • the board provides Bluetooth and Wifi connectivity, which is nice

We have already given two sessions of our Embedded Linux system development training with the IGEPv2, and all our future sessions of this training will use this hardware platform, so the participants will benefit from a more modern platform, with far more capabilities than our previous AT91-based training hardware. This is also the board we are now giving to the participants to our public training sessions, so those participants come back home with a very nice and powerful platform which allows countless experiments around embedded Linux. Note that we also intend to port our Embedded Linux kernel and driver development training session to the IGEPv2 platform in the near future.

ELC 2011 videos

The Embedded Linux Conference 2011 took place between April, 11th and April, 13th in its now usual place, the Kabuki hotel in San Francisco, California. It was the first edition organized since the merge of the CE Linux Forum into the Linux Foundation. During three days, three parallel tracks of talks and BoFs about technical topics around embedded Linux : kernel support, power management, build systems, file systems, real-time, and more.

As usual, part of the Bootlin team was at this Embedded Linux Conference, in order to keep up with the latest developments from the embedded Linux community. Gregory Clement (left on the picture), Maxime Ripard (right on the picture) and myself (center on the picture) were present, and we recorded all talks of the conference. And just a little bit more than one month later, we are ready to announce that all videos are now available online, in 1080p high-definition, and in a lower 450p resolution, encoded with the new VP8 codec.

Bootlin at ELC 2011
Bootlin at ELC 2011. From left to right: Gregory Clement, Thomas Petazzoni and Maxime Ripard.

Amongst all the conferences below, each of us have selected the three ones we thought were the most interesting ones (note that the top three for each us is necessarily composed of distinct talks, as none of us have seen the same talks since we had to record talks from three different sessions in parallel) :

  • For Gregory Clement, the top three is: Yoshiya Hirase talk about Faster Resume For More Energy Savings on MeeGo, Arnd Bergmann talk about Optimizations For Cheap Flash Media (which follows Arnd article on the same topic in LWN) and a set of three related talks about the video infrastructure in the Linux kernel, that Gregory recommends to watch in this order: Media Controller Framework (MCF) For OMAP2+ Display Subsystem (Sumit Semwal), Video4linux: Progress, New videobuf2 Framework and the Future (Hans Verkuil) and Bringing up HDMI Display for OMAP4 Panda Board – Design, Challenges and Lessons Learned (Mythri pk).
  • For Maxime Ripard, the top three is: John Stultz talk about Android for servers, Mike Anderson talks about ARM NEON and GPU programming, Wolfram Sang talk about Helping the process
  • For myself, the top three is: Jesse Barker talks about the ARM Graphics ecosystem which gives a nice overview of the state of this topic, Hai Shalom talk about PCD (which is an original and interesting replacement for init), Dave Stewart talk about The Yocto Project and its Application Development Toolkit (because it gives details on how Yocto is supposed to be used for application development, a topic I’m interested in as a Buildroot developer)

It is also worth noting that this Embedded Linux Conference was co-located with the first edition of the Android Builders Summit, for which we will soon publish videos as well. The next embedded Linux conference will take place in Europe, in Prague from October 26th to 28th, co-located with the first edition of LinuxCon Europe and just after the Kernel Summit. Prague will really be full of Linux developers during this end of October, it’s time to book this week on your agenda as well !

Creative commonsIn agreement with the speakers, these videos are released under the terms of the Creative Commons Attribution-ShareAlike 3.0 license.

Finally, the list of all videos of Embedded Linux Conference 2011, along with their corresponding slides :

Tim BirdVideo capture
Sony Network Entertainment
Welcome Keynote
Video (10 minutes):
full HD (131M), 450×800 (43M)

Dirk Hohndel, Richard PurdieVideo capture
Intel, Linux Foundation
The Yocto Project
Video (35 minutes):
full HD (458M), 450×800 (140M)

Keshava MunegowdaVideo capture
Texas Instruments
Power Fail Safe FAT File Systems
Slides
Video (48 minutes):
full HD (693M), 450×800 (203M)

Frank RowandVideo capture
Sony
Identifying embedded real-time issues: I-cache and locks
Slides
Video (46 minutes):
full HD (471M), 450×800 (147M)

Bruno Cardoso LopesVideo capture
University of Campinas
LLVM, Clang and Embedded Linux Systems
Slides
Video (50 minutes):
full HD (593M), 450×800 (164M)

Steven RostedtVideo capture
RedHat
Kernel Shark Tutorial
Video (49 minutes):
full HD (743M), 450×800 (215M)

Kang DongwookVideo capture
ETRI
Snapshoot Booting on Embedded Linux
Slides
Video (33 minutes):
full HD (284M), 450×800 (95M)

Khem RajVideo capture
State of OpenEmbedded Internal Toolchain and SDKs
Slides
Video (41 minutes):
full HD (289M), 450×800 (119M)

David RuslingVideo capture
Linaro
Linaro: a year of change
Slides
Video (50 minutes):
full HD (529M), 450×800 (173M)

Hai ShalomVideo capture
Atheros
Control, recover and debug your embedded product with PCD
Slides
Video (50 minutes):
full HD (470M), 450×800 (160M)

Gene SallyVideo capture
Zigbee Networking and Linux
Video (53 minutes):
full HD (262M), 450×800 (139M)

Xi WangVideo capture
Broadcom
Solving real-time scheduling problems with RT_PREEMPT and deadline-based scheduler
Slides
Video (43 minutes):
full HD (422M), 450×800 (141M)

Mike AndersonVideo capture
The PTR Group
ARM Neon instruction set and why you should care
Slides
Video (53 minutes):
full HD (527M), 450×800 (169M)

Darren HartVideo capture
Intel
Yocto Project: Practical Kernel Development Tutorial
Video (52 minutes):
full HD (551M), 450×800 (196M)

Arnd BergmannVideo capture
IBM
Optimizations for cheap flash media
Slides
Video (49 minutes):
full HD (482M), 450×800 (160M)

Wolfram SangVideo capture
Pengutronix
Developer’s diary: helping the process
Slides
Video (39 minutes):
full HD (315M), 450×800 (112M)

Rajesh LalVideo capture
Nokia
Fun with QML and Javascript
Slides
Video (39 minutes):
full HD (250M), 450×800 (108M)

Thomas GleixnerVideo capture
Linutronix
RT-Preempt: what’s the state and why there is no roadmap
Slides
Video (46 minutes):
full HD (447M), 450×800 (149M)

Jason KridnerVideo capture
Texas Instruments
High-level web interface to low-level I/O on the BeagleBoard
Slides
Video (36 minutes):
full HD (370M), 450×800 (115M)

Arnd BergmannVideo capture
IBM
Becoming part of the Linux kernel community
Slides
Video (34 minutes):
full HD (376M), 450×800 (126M)

Paul MundtVideo capture
Renesas
Working with hardIRQs: life beyond static IRQ assignments
Slides
Video (36 minutes):
full HD (330M), 450×800 (113M)

Amit KucheriaVideo capture
Linaro
Powerdebugging inside Linaro
Slides
Video (46 minutes):
full HD (309M), 450×800 (136M)

Mike AndersonVideo capture
The PTR Group
High-performance computing using GPUs
Slides
Video (57 minutes):
full HD (615M), 450×800 (185M)

Paul LarsonVideo capture
Canonical
Linaro automated validation on ARM
Video (51 minutes):
full HD (581M), 450×800 (184M)

Dave StewartVideo capture
Intel
The Yocto project and its application development toolkit (ADT) – The answer to effective embedded application development
Video (42 minutes):
full HD (362M), 450×800 (139M)

Damian Hobson Garcia, Katusya Matsubara, Takanari Hayama, Hisao MunakataVideo capture
Igel
Integrating a Hardware Video Codec into Android Stagefright using OpenMAX IL
Slides
Video (55 minutes):
full HD (564M), 450×800 (177M)

Koen KooiVideo capture
Texas Instruments
Integrating OpenEmbedded and Yocto
Slides
Video (52 minutes):
full HD (465M), 450×800 (159M)

Mark GrossVideo capture
Intel
How to power tune a device running on a Linux kernel for better suspend battery life
Slides
Video (49 minutes):
full HD (273M), 450×800 (129M)

Remi LorriauxVideo capture
Adeneo Embedded
Real-time audio on embedded devices
Slides
Video (44 minutes):
full HD (437M), 450×800 (138M)

Magnus DammVideo capture
Runtime PM: upstream I/O device power management
Slides
Video (53 minutes):
full HD (486M), 450×800 (164M)

Jesse BarkerVideo capture
Linaro
Linux graphics meets the ARM ecosystem
Slides
Video (50 minutes):
full HD (329M), 450×800 (147M)

David AndersVideo capture
Texas Instruments
Board bringup: open-source hardware and software tools
Slides
Video (38 minutes):
full HD (376M), 450×800 (118M)

John WilliamsVideo capture
PetaLogix
Dynamic co-simulation of FPGA-based systems on chip
Slides
Video (57 minutes):
full HD (567M), 450×800 (198M)

Summit SemwalVideo capture
Texas Instruments
Media Controller Framework (MCF) for OMAP2+ display subsystem
Slides
Video (49 minutes):
full HD (518M), 450×800 (155M)

John StultzVideo capture
IBM
Android for servers?
Slides
Video (37 minutes):
full HD (425M), 450×800 (137M)

Anand GadiyarVideo capture
Texas Instruments
Tools and techniques for debugging embedded systems
Slides
Video (30 minutes):
full HD (139M), 450×800 (81M)

Hans VerkuilVideo capture
Cisco
Video4linux: progress, new videobuf2 framework and the future
Slides
Video (56 minutes):
full HD (534M), 450×800 (171M)

Yoshiya HiraseVideo capture
Nokia
Faster resume for more energy saving on MeeGo
Slides
Video (58 minutes):
full HD (727M), 450×800 (218M)

Jake EdgeVideo capture
Linux Weekly News
What embedded Linux developers should know about IPv6
Slides
Video (46 minutes):
full HD (266M), 450×800 (122M)

Grégoire GentilVideo capture
Always Innovating
Hot multi-OS switch: how to run Ubuntu, ChromiumOS, Android at the same time on an embedded device
Video (61 minutes):
full HD (515M), 450×800 (174M)

Xi WangVideo capture
Broadcom
Controlling memory footpring at all layers: Linux kernel, applications, libraries and toolchain
Slides
Video (38 minutes):
full HD (511M), 450×800 (152M)

Tom Zanussi, Saul WoldVideo capture
Building custom embedded images with Yocto
Slides
Video (49 minutes):
full HD (500M), 450×800 (173M)

Philip BalisterVideo capture
Open SDR
A high performance interface between the OMAP3 and a FPGA
Slides
Video (51 minutes):
full HD (347M), 450×800 (149M)

Jean PihetVideo capture
NewOldBits.com
The evolution of tracing and profiling for power management and accelerators
Slides
Video (40 minutes):
full HD (428M), 450×800 (133M)

Elizabeth FlanaganVideo capture
Intel
Delivering predictability: the Yocto project autobuilder, automated sanity testing, license collection and build statistics tracking
Slides
Video (48 minutes):
full HD (241M), 450×800 (133M)

Mythri pkVideo capture
Texas Instruments
Bringing up HDMI display for OMAP4 Panda board: design, challenges and lessons learned
Slides
Video (40 minutes):
full HD (363M), 450×800 (122M)

Khem RajVideo capture
Debug/develop uClibc with QEMU
Slides
Video (35 minutes):
full HD (226M), 450×800 (98M)

Gunter Ravi SankarVideo capture
Samsung
What are and how to find a program’s unused DSOs
Slides
Video (49 minutes):
full HD (453M), 450×800 (143M)

Bootlin at the Embedded Linux Conference and Android Builders Summit

In just two weeks from now, the Embedded Linux Conference will start in San Francisco, followed by the Android Builders Summit, at the usual Hotel Kabuki location, where the conference is taking place for the third consecutive year.

Embedded Linux Conference 2011

The program of the Embedded Linux Conference has been announced recently, and as usual, features a wide set of technical embedded Linux talks:

  • Filesystem/storage: Power Fail Safe FAT File System, Optimizations For Cheap Flash Media, from Arnd Bergmann, who has also recently published a very interesting article on the same topic.
  • Power management: Faster Resume For More Energy Savings on MeeGo, Powerdebug(ging): A Linaro Perspective, How to Power Tune a Device Running on a Linux Kernel for Better Suspend Battery Life, The Evolution of Tracing and Profiling for Power Management and Accelerators, Runtime PM: Upstream I/O Device Power Management
  • Real-time: Solving Real-Time Scheduling Problems with RT_PREEMPT and Deadline-Based Scheduler, Real-time Audio on Embedded Devices, Identifying Embedded Real-Time Latency Issues: I-Cache and Locks
  • Build system, with a huge number of Yocto-related talks, but no other build systems represented: State of OpenEmbedded Internal Toolchain and SDKs, Yocto Project: Practical Kernel Development Tutorial, Building Custom Embedded Images with Yocto, The Yocto Project and its Application Development Toolkit (ADT) – The Answer to Effective Embedded Application Development, Yocto Project Community BoFs, Delivering Predictability: The Yocto Project Autobuilder, Automated Sanity Testing, License Collection, and Build Statistics Tracking
  • Multimedia: Fun with QML and JavaScript, Integrating a Hardware Video Codec into Android Stagefright using OpenMAX IL, Media Controller Framework (MCF) For OMAP2+ Display Subsystem, Video4linux: Progress, New videobuf2 Framework and the Media Controller, Bringing up HDMI Display for OMAP4 Panda Board – Design, Challenges and Lessons Learned, Linux Graphics Meets the ARM Ecosystem
  • FPGA: Dynamic Co-simulation of FPGA-based Linux Systems-on-Chip, A High Performance Interface Between the OMAP3 and an FPGA
  • Networking: What Embedded Linux Developers Should Know About IPv6, Zigbee Networking & Linux
  • Debugging: Kernel Shark Tutorial and Tools and Techniques for Debugging Embedded Systems
  • Optimization: Snapshot Booting on Embedded Linux, ARM Neon Instruction Set and Why You Should Care, Controlling Memory Footprint at All Layers: Linux Kernel, Applications, Libraries and Toolchain, High-Performance Computing using GPUs, What Are and How to Find a Program’s Unused DSOs
  • Low-level: Board Bringup: Open Source Hardware and Software Tools, Working with HardIRQs: Life Beyond Static IRQ Assignments, Genie in the Bottle: Linux Drivers for the AM1808 PRU
  • And many other talks on various topics: LLVM, Clang and Embedded Linux Systems, Linaro: A Year of Change, Control, Recover and Debug Your Embedded Product with PCD, Developer’s Diary: Helping the Process, High-Level Web Interface to Low-Level Linux I/O on the Beagleboard, Linaro Automated Validation on ARM, Crowd Sourcing and Protecting the Open Source Community, Android for Servers?, Hot Multi-OS Switch: How to run Ubuntu, ChromiumOS, Android at the Same Time on an Embedded Device.

This edition will be the first one organized since the merge between the CE Linux Forum into the Linux Foundation, and will therefore be a great opportunity to see if this merge had any impact on the technical quality of the conference.

My colleagues Maxime Ripard (who joined Bootlin just a week ago) and Gregory Clement as well as myself will be present at the Embedded Linux Conference and the Android Builders Summit, and we will as usual record all talks of both of these conferences and will put them online, as we have done recently for the talks that took place during the Embedded Linux Conference Europe 2010 in Cambridge. Do not hesitate to meet us in San Francisco!

ELC-E 2010 tutorial videos

Videos from the embedded Linux and Android tutorials at ELC-E 2010, by Chris Simmonds

As releasing ELC-E 2010 videos, here are recordings of the embedded Linux and Android tutorials, performed by Chris Simmonds on October 26, 2010.

Chris SimmondsVideo capture
2net
The Embedded Linux Quick Start Guide – Part 1
Slides
Video (52 minutes, 397M)
Chris SimmondsVideo capture
2net
The Embedded Linux Quick Start Guide – Part 2
Slides
Video (79 minutes, 660M)
Chris SimmondsVideo capture
2net
The Embedded Linux Quick Start Guide – Part 3
Slides
Video (67 minutes, 501M)
Chris SimmondsVideo capture
2net
What else can you do with Android? – Part 1
Slides
Video (49 minutes, 432M)
Chris SimmondsVideo capture
2net
What else can you do with Android? – Part 2
Slides
Video (31 minutes, 293M)
Chris SimmondsVideo capture
2net
What else can you do with Android? – Part 3
Slides
Video (59 minutes, 545M)

Linux Kernel Development, third edition

Linux Kernel Development, by Robert Love, 3rd edition

Linux Kernel Development is a book authored by Robert Love, a famous kernel developer. Contrary to the very famous Linux Device Drivers book, Linux Kernel Development is not oriented towards driver development, but instead covers how the core Linux kernel works.

Having this knowledge is not absolutely necessary to write Linux device drivers, but having a good overall understanding of the kernel always help to understand what’s going on in your system, even at the application level. In July this year, the third edition of Linux Kernel Development has been published, which upgrades the book contents to kernel version 2.6.34, a good opportunity to have a new look at the book that Bootlin received a few weeks ago.

After a quick introduction to the kernel sources (configuring, building, organization of the source tree), the book immediately dives into kernel internals:

  • Process management: how the kernel represents processes and their state, how processes are created inside the kernel, how threads are handled, are processes are terminated.
  • Process scheduling: a full chapter dedicated to the Linux kernel process scheduler. The new CFS scheduler is of course covered in great detail, with large portion of commented source code, for those who want to understand the fine details of the scheduler. Topics such as process sleep/wake-up, preemption, real-time scheduling policies are also covered.
  • System calls are then covered: how they are implemented, how parameters are passed from userspace to the kernel, etc. The call path from your user-space application down to the kernel is well explained in this chapter.
  • Kernel data structures: a generic chapter which details the kernel API for linked lists, queues, maps, and binary trees. Those APIs are omni-present inside the kernel, and it’s therefore a good idea to know how they work, both for understand existing code and for writing new code.
  • Interrupts: how interrupts are handled and how one can write an interrupt handler. Unfortunately, the newly introduced threaded interrupt handlers are not covered, but it’s true that their usage is not yet very widespread inside the mainline kernel.
  • Bottom halves and deferring work, a topic closely related to interrupt handling. It covers bottom halves, softirqs, tasklets and workqueues.
  • Kernel synchronization: two chapters are dedicated to this topic. First a chapter detailing why synchronization is needed, what are the sources of concurrency and what should be protected against concurrent access. And then a chapter detailing the mechanisms provided by the kernel to implement proper synchronization: atomic operations, spin locks, reader-writer spin locks, semaphores, reader-writer semaphores, mutexes, completion variables, sequential locks, preemption disabling, ordering and barriers
  • Timers and time management details how the kernel manages time: ticks, jiffies counter, timers, delaying execution of code are covered in this chapter. There are unfortunately no details about the clocksource and clockevents infrastructure, and no details about how timers and high-resolution timers are implemented. Contrary to other chapters that go fairly deep into the implementation details, this one mostly only covers the API to time management rather than the internals.
  • Memory management is the topic of the following chapter: physical memory management with the page allocator and the physical zones, then the kmalloc, vmalloc and SLAB allocators are covered. High-memory mappings, a topic specific to 32 bits architectures having more than a gigabyte of RAM is also covered in detail. The per-cpu interface is also covered, and will help those who want to understand parts of the kernel that have been optimized for scalability on multiple CPUs.
  • The Virtual Filesystem, with its different objects: superblock, inode, dentry and file is covered in good detail.
  • The block layer is then covered, with a description of the role of the bio structure, the request queues, and the I/O schedulers.
  • Then, the book goes back to more details about the internals of memory management: the mm_struct memory descriptor, the virtual memory areas (so called VMAs) and how they relate with the mmap/munmap system calls. The next chapter continues with a detailed description of the page cache implementation.
  • A fairly strange chapter called “Devices and modules” gives some information about kernel modules (how to build them, how to use module parameters, how dependencies are handled), then covers the internal of the device model (kobjects, ktypes, ksets, krefs) and finally sysfs. Just like the chapter covering the device model in the third edition of Linux Device Drivers, I think it totally misses the point. All the kobject, ktypes, ksets and krefs stuff is very low-level plumbing used by the Linux device model, but it is not exactly what the driver developer needs to interact with in the first place. In my opinion, a good description of the device model should rather explain what struct bus_type, struct driver and struct device are, how they are specialized for the different bus types in pci_driver, pci_device, usb_driver, usb_device, platform_driver, platform_device, and how the registration/probing of drivers and devices is done. I’ve recently given a talk about this topic, the video is in French, but the slides are in English.
  • Debugging is then covered: printk of course, but also oopses, debugging-related kernel options, the magic SysRq key, kernel debuggers, etc.
  • A rather generic chapter about Portability is then proposed, and finally a chapter about Patches, Hacking and the community that details the kernel community, the kernel coding style, how to generate and submit patches, etc.

All in all, Linux Kernel Development remains very good reading. I particularly appreciate the writing style of Robert Love, who manages to make a deeply-technical book interesting and easy to read. Of course, there are some topics in the kernel in which I had to dive myself and for which I’d expect to see more details in this book, but giving every possible detail about a huge beast such as the Linux kernel in just 400 pages is not possible!