Posts Tagged ‘real-time’

Embedded Linux Conference & IoT Summit 2018 Schedule

February 13th, 2018 No comments

The Embedded Linux Conference 2018 and the OpenIoT Summit 2018 will jointly take place next month, on March 12 – 14, 2018 in Portland, Oregon, USA. The former is a “vendor-neutral technical conference for companies and developers using Linux in embedded products”, while the latter is a “technical conference for the developers and architects working on industrial IoT”. The Linux Foundation has already published the schedule, and it’s always useful to learn what will be discussed about even for people who won’t attend.

With that in mind, here’s my own virtual schedule with some of the talks I find interesting / relevant to this blog.

Monday, March 12

  • 10:50 – 11:40 – Progress in the Embedded GPU Ecosystem by Robert Foss, Collabora Ltd.

Ten years ago no one would have expected the embedded GPU ecosystem in Linux to be what it is now. Today, a large number of GPUs have Open Source support and for those that aren’t supported yet, improvements are happening at a rapid pace.

In just the last year Vivante GPUs have gained mainline support and Mali GPUs have seen good progress being made.

In this talk, Robert will cover GPUs in the embedded space and give an overview about their current status, what lies ahead and how the Open Source state of the art compares to the proprietary alternatives.

  •  11:50 – 12:40 – Zephyr LTS Release, What to Expect and Why are We Doing This by Anas Nashif, Intel

After eleven 1.x.x releases of Zephyr since the project has launched 2 years ago, the Zephyr project is planning to release Zephyr LTS in 2018 with many new features that have been in the works for the last year, stable APIs and with the goal of taking a subset of the released project code through various certification activities.

In this talk the status plans for Zephyr LTS will be presented and discussed and the next steps that the project will take after the LTS release.

  • 14:00 – 14:50 – Preempt-RT Raspberry Pi Linux by Tiejun Chen, VMware

As we know, the Raspberry Pi is a series of small single-board computers developed in the United Kingdom by the Raspberry Pi Foundation to promote the teaching of basic computer science in schools and in developing countries. Now it is very popular around our IoT world, and you can see many guys use Pi to build great things, and even it can play a role in the production environment. The official Raspberry Pi Linux maintains Linux kernel specific to Pi platform. But it does not include Preempt RT Linux support. Obviously, in some IoT cases we really need to meet hard real time requirement. In this presentation, we will review if-how we can integrate Preempt RT Linux patches to Pi Linux, an see what the problems are for this particular hardware platform.

  • 15:00 – 15:50 – OpenEmbedded/Yocto on RISC-V – New Kid on the Block by Khem Raj, Comcast

RISC-V a new open source ISA based architecture is rapidly gaining acceptance in embedded space. Several core packages e.g. gcc toolchain, linux kernel, binutils, newlib, qemu has already been ported for RISC-V. At this point, OpenEmbedded is one of first embedded linux distribution frameworks to support RISC-V architecture. This talk will cover the status of support as the core support has been upstreamed into OpenEmbedded-core, additionally SOC layer meta-riscv is also created which would serve as common layer for all RISC-V based SOCs.

  • 16:10 – 17:00 – Bluetooth Mesh with Zephyr OS and Linux by Johan Hedberg, Intel

Bluetooth Mesh is a new standard that opens a whole new wave of low-power wireless use cases. It extends the range of communication from a single peer-to-peer connection to a true mesh topology covering large areas, such as an entire building. This paves the way for both home and industrial automation applications. Typical home scenarios include things like controlling the lights in your apartment or adjusting the thermostat. Although Bluetooth 5 was released over a year ago, Bluetooth Mesh can be implemented on any device supporting Bluetooth 4.0 or later. This means that we’ll likely see very rapid market adoption of the feature.

The presentation will give an introduction to Bluetooth Mesh, covering how it works and what kind of features it provides. The talk will also give an overview of Bluetooth Mesh support in Zephyr OS and Linux and how to create new wireless solutions with them.

  • 17:10 – 18:00 – Drive your NAND within Linux by Miquèl Raynal, Bootlin (formerly Free Electrons)

NAND flash chips are almost everywhere, sometimes hidden in eMMCs, sometimes they are just parallel NAND chips under the orders of your favorite NAND controller. Each NAND vendor follows its own rules. Each SoC vendor creates his preferred abstraction for interacting with these chips.

Handling all of that requires some abstraction, and that is currently being enhanced in Linux! A new interface, called exec_op is showing up. It has been designed to match the most diverse situations. It should ease the support of advanced controllers as well as the implementation of vendor-specific NAND flash features.

This talk will start with some basics about NAND memories, especially their weaknesses and how we get rid of them. It will also show how the interaction between NAND chips and controllers has been standardized over the years and how it is planned to drive NAND controllers within Linux.

Tuesday, March 13

  •  10:50 – 11:40 – Comparing and Contrasting Embedded Linux Build Systems and Distributions by Drew Moseley,

We will discuss the various options for creating embedded Linux operating systems. We will provide a basic description of each option, including an overview of the workflow for each choice. The talk will cover the advantages and disadvantages of each of these options and provide viewers with a matrix of design considerations to help them pick the right choice for their design. We will cover the following options:

  • Yocto/OpenEmbedded
  • Buildroot
  • OpenWRT/LEDE
  • Slimmed down desktop distributions (e.g. Debian, Raspbian, Ubuntu)

We will also touch upon other tools, such as crosstool-ng and ucLinux, which are peripherally related to building embedded Linux systems. The focus for this section will be to make the viewers aware of these tools as they frequently come up while researching embedded Linux so that you are better informed which tools are available.

  • 11:50 – 12:40 – The Things Network: An IOT Global Phenomenon by Bryan Smith, Tacit Labs

IoT has many connectivity options and systems based on Low Power Networks(LPN’s) such as LoraWAN are showing a great deal of promise. LoraWAN uses the ISM Band which doesn’t require a license for use.

The Things Networks (TTN) is a community about LoraWAN, Low Power Wide Area Network (LPWAN). It’s collaboratively built by passionate people, Open Source Software and Open Governance. The network has a manifesto and fair access policy that governs its use and management. In the session we’ll discuss:

  • The technology behind LoraWAN, TTN and similar networks.
  • TTN’s impact on public and private LPWAN’s.
  • The initiators and communities that install and build LoraWAN gateways.
  • Lastly we’ll discuss the impact of the deployments in real world use cases.

There will also be a live demo of a LoraWAN gateway and node in action on several public networks including TTN as well as others.

  • 14:00 – 14:50 – I + I2C = I3C: What’s in this Additional ‘I’? by Boris Brezillon, Bootlin (formerly Free Electrons)

The MIPI Alliance recently released version 1 of the I3C (pronounce ‘eye-three-see’) bus specification, which is supposed to be an improvement over the long-standing I2C and SPI protocols. Compared to I2C/SPI, I3C provides a higher data rate, lower power consumption and additional features such as dynamic address assignment, host join, in-band interrupts. For the last year or so, Free Electrons has been working with Cadence Design Systems on supporting this new kind of bus in Linux.

With this talk we would like to introduce this new bus and the concepts it brings to the table. We will also detail how we plan to expose the new features exposed by the I3C protocol in Linux and go through future possible improvements of the I3C framework that has already been submitted for review on the Linux kernel mailing list.

  • 15:00 – 15:50 – Android Common Kernel and Out of Mainline Patchset Status by Amit Pundir & John Stultz, Linaro

A quick overview of what the speakers ares going to cover in this session.

  • A brief background on Android common kernels – Out of tree Android patches and how they have evolved over time.
  • The current/active patchset introduction and status – Their use cases in Android and on-going upstreaming efforts if any.
  • A brief Intro to android-mainline-tracking tree.
  • Rebasing latest android-$LTS tree to latest linux release tag
  • Find/Report/Fix Android regressions or ABI breakages in mainline kernel.
  • 16:20 – 17:10 – Tock, The Operating System for a Programmable IoT by Amit Levy, Stanford University

Tock is an open-source operating system for low-power ARM Cortex-M microcontrollers that enables radically different kinds of embedded and IoT products.

In typical embedded systems, every line of code is fully trusted because embedded operating systems lack traditional isolation mechanisms like processes. Unfortunately, this makes developing secure products difficult, and running third-party applications virtually impossible.

Tock uses a language sandbox in the kernel and a process-like hardware enforced mechanism in userspace to isolate third-party and other untrusted code in the system.

In this presentation I’ll introduce Tock’s vision for IoT and how its isolation mechanisms work. Then, I’ll use examples of deployed systems and products using Tock to show how developers can use it to build more secure and extensible IoT systems today.

  • 19:00 – 20:00 – BoF: Open Source Hardware by Drew Fustini, OSH Park

Open Source Hardware BoF (Birds of a Feather) session for those interested in how Open Source Hardware design can benefit embedded Linux systems.

The session will start will start with a short presentation of a few slides to clarify terminology and highlight Open Source Hardware projects relevant to Linux. The panelists will then lead a discussion with the BoF attendees about the benefits and challenges of designing Open Source Hardware.

Jason and Drew can talk about the experience of working with community, manufacturers, and distributors to create an Open Source Hardware platform. Leon can speak about his experience of learning hardware design as a software engineer, and how he took his Raspberry Pi HATs from concept to product. John can speak about his experience leading an Open Source Hardware platform within a large corporation.

Wednesday, March 14

  • 11:05 – 11:55 – Landscape of Linux IoT Ecosystems by Christian Daudt, Cypress Semiconductor

IoT products are getting richer in their functionality daily, and as a result there is a trend for increased use of Linux in these products. As we are early in the IoT ecosystem cycle, there is a large number of projects and products vying for developer attention as frameworks and protocols to be used in new product development. This talk provides an overview of the options available and how they relate to each other. It covers OS stacks such as EdgeX Foundry, Automotive Grade Linux, Android Things, IoTivity, Tizen, etc.. as well as IoT-tailored cloud integrations from cloud vendors such as AWS, Google, Microsoft.

  • 12:05 – 12:55 – CPU Power Saving Methods for Real-time Workloads by Ramesh Thomas, Intel

Configurations created for real time applications mostly disable power management completely to avoid any impact on latency. It is however, possible to enable power management to a degree to which the impact on latency is tolerable based on application requirements. This presentation addresses how CPU idle states can be enabled and tuned to allow power savings while running real time applications.

The presentation will give a background of the issues faced by real-time applications when CPU power management is enabled. It will then explain tools, configurations and methods that can be used to tune applications and CPU power management in the kernel to be able to save power without impacting the deterministic latency tolerance requirements.

  • 14:30 – 15:20 – Debian for Embedded Systems: Best Practices by Vagrant Cascadian, Aikidev, LLC

As embedded hardware becomes more capable, Debian becomes an attractive OS for projects. Debian provides clear licensing, a solid technical foundation, and over twenty-five thousand software projects already available within Debian.

Unfortunately, embedded system projects may make changes to a customized Debian OS in ways that make it difficult to apply security updates or system upgrades. This can lead to an unmaintained fork of Debian with long-standing security vulnerabilities unfixed in the hands of end-users. Nobody likes bit-rot.

Many of these common pitfalls can be mitigated or avoided entirely by understanding Debian’s culture, infrastructure, technical norms, and contribution processes. These understandings will improve embedded systems using Debian over the long-term.

  • 15:30 – 16:20 – Civil Infrastructure Platform: Industrial Grade Open Source Base-Layer by Yoshitake Kobayashi, Toshiba Corporation, Software Development and Engineering Center

The Civil Infrastructure Platform (CIP) is creating a super long-term supported (SLTS) open source “base layer” of industrial grade software. The base-layer consists of the SLTS kernel and a basic set of open source software and standardization concepts. By establishing this “base layer,” the CIP Project will enable the use and implementation of software building blocks in civil infrastructure projects. Currently, all civil infrastructure systems are built from the ground up, with little re-use of existing software building blocks, which drains resources, money and time. In this devroom, we’ll share project strategy, use cases, roadmap, milestones and policies. We’ll also share technical details for each development activities for the base-layer that includes open source, real-time development tools, testing and answer questions.

  • 16:30 – 17:20 – 3D Printing with Linux and Xenomai by Kendall Auel, 3D Systems Corp.
Software running on embedded Linux with Xenomai is used to control a 3D printer. The lessons learned and practical advice will be shared in this presentation. There were many challenges to overcome. A complete 3D printing system requires precise motion control, thermal control, material delivery and monitoring, and coordinated data transfers. All concurrent real time processes must be coordinated and managed, while providing interactive response to user input. In parallel with the real time processing, the system must slice the 3D model into layers for printing, which is by its nature a compute-bound application. The dual-kernel architecture of Linux with Xenomai was ideal for maintaining low and predictable latencies for real time control, while allowing the complex and resource intensive slicing application to run in parallel.

Selecting the sessions was not easy as most talks are relevant, so I’d recommend checking out the whole schedule.

The Embedded Linux Conference & OpenIoT Summit require registration with the fees listed as follows:

  • Early Bird Fee: US$550 (through January 18, 2018)
  • Standard Fee: US$700 (January 19,  February 17, 2018)
  • Late Fee: US$850 (February 18, 2017 – Event)
  • Academic Fee: US$200 (Student/Faculty attendees will be required to show a valid student/faculty ID at registration.)
  • Hobbyist Fee: US$200 (only if you are paying for yourself to attend this event and are currently active in the community)

FOSDEM 2018 Open Source Developers Meeting Schedule

January 23rd, 2018 5 comments

FOSDEM (Free and Open Source Software Developers’ European Meeting) occurs every year on the first week-end of February, where developers meet for two days discussing about open source software projects. FOSDEM 2018 will take place on February 3-4 this year with  652 speakers, 684 events, and 57 tracks, an increase over  last year 608 speakers, 653 events, and 54 tracks. There will be 8 main tracks namely: Community, History, Miscellaneous, Performance, Python, Security and Encryption, Space, and Global Diversity CFP Day.

There will also be 33 developer rooms, and since the full schedule is now available, I’ll make a virtual schedule mostly based on sessions from the Embedded, mobile, and automotive, Hardware Enablement, and Internet of Things devrooms.

Saturday 3, 2018

  • 09:50 – 10:15 – Turning On the Lights with Home Assistant and MQTT by Leon Anavi

In this presentation you will learn the exact steps for using MQTT JSON Light component of the open source home automation platform Home Assistant for controlling lights through the machine-to-machine protocol MQTT. Practical examples for low cost devices combining together open source hardware with free and open source software will be revealed. The presentation will provide general overview of Home Assistant, details about the software integration of new devices to it through the MQTT protocol and open source MQTT brokers such as Mosquitto. We will do a code review of an open source Linux daemon application for Raspberry Pi, written in the C programming language and based on the Paho library for MQTT client and the piGPIO library used for pulse-width modulation (PWM) control of a RGB LED strip. We will compare it to an implementation of the same features for the microcontroller with WiFi ESP8266 written as a sketch for the Arduino environment. Furthermore, the presentation will include details about reading data from various sensors and their setup in Home Assistant.

  • 10:25 – 10:50 – Accessing your Mbed device from anywhere using Pagekite by Bert Outtier

When looking at home automation solutions available in the market nowadays, one of the most important and expected features is to be able to control your home automation installation from anywhere in the world using a smartphone app. A vendor of a low-cost home automation solution requested us to add such a feature to their existing IP gateway product, which only allowed for users to control their home automation system with their smartphone while they are connected to their local network at home. We were asked to make it possible to let the smartphone app connect to the IP gateway from anywhere in the world. This vendor’s IP gateway hard- and software was based on the Mbed platform, so they needed a solution that could fit within Mbed.

Since our client wanted an open-source, secure, low-cost and easy to set up solution that he could host himself, we opted to go for Pagekite. However, since Mbed does not support OpenSSL, Linux sockets or libev, the existing libpagekite C library was not an option to start from. So we started to implement a Mbed flavour of the library ourselves, and decided to make it open-source

  • 11:00 – 11:30 – The free toolchain for the STM8 by Philipp Klaus Krause

The STM8 is a popular 8-bit architecture by ST Microelectronics commonly used in household electronics, automotive application and industrial controls. For quite a while there were no free tools, and the irregular architecture makes it hard to support in GCC or LLVM. In recent years free tools for it started to appear and now form a free toolchain that surpassed preexisting non-free ones. The most important part is the Small Device C Compiler (SDCC). New tree-decomposition-based algorithms from recent compiler research have been implemented in SDCC, including a new register allocator particularly suited to irregular architectures with few registers. SDCC quickly surpassed the non-free compiler in standard compliance and OS support and generates substantially faster integer code. Programs can be flashed by stcgal (via a serial link on STM8 devices that have a bootloader) and stm8flash (via the SWIM interface of ST-LINK hardware). OpenOCD and GDB allow on-target debugging via the ST-LINK. IDEs complete the development environment. However, stcgal still needs non-free binary blobs for use with some devices and the ST-LINK has non-free firmware. SDCC still falls short in floating-point performance. While there are some ports of free RTOSes that use the free toolchain for the STM8, more would be desirable.

  • 11:30 – 12:00 – Building RT Linux distribution with Yocto by Pierre Ficheux

The conference will describe how to use PREEMPT_RT and Xenomai with Yocto build system – building image and SDK – developing simple application – testing performances.

Using RT extension with Yocto is not that easy because linux-yocto-rt kernel is not usable on main embedded target such as ARM (as it works on QEMU target only). Using Xenomai is much more complicated as it needs several steps (patching the kernel, installing user-space libraries, building an extended SDK).

During the conference we will describe how to build a Yocto Linux image using PREEMPT_RT for famous boards such as Pi 3 or BeagleBone Black.

Some Xenomai support is provided by meta-eldk from DENX but it supports only Xenomai 2.6. We will describe meta-xenomai as we maintain it for our customers (available on GitHub). That new meta-xenomai layer is based on Xenomai 3.x and very recent kernel.

Then we will explain how to build a simple Xenomai application based on a periodic task. Finally we will compare performances of both extension (PREEMPT_RT and Xenomai) on same hardware.

  • 12:00 – 13:00 – How to keep your embedded Linux up and running? by Krzysztof Opasiak

Userspace software is imperfect and we all know about this. Running it for 5 minutes seems to be easy but what about days or weeks? This problem already gave server guys a lot of sleepless nights. Nowadays also IoT and embedded Linux world is facing very the same problem. Unfortunately solutions known from server world (Nagios and friends) usually cannot be directly applied.

During this talk, Krzysztof will discuss problems related to monitoring and “healing” embedded Linux distribution. First, most common server approaches will be described. After that, Krzysztof will try to identify key problems of applying this solution to embedded platform. Then Krzysztof will introduce faultd – small but extendable daemon for system monitoring and CPR;). How to use it? What can it do? What are the advantages and disadvantages? All those questions should be answered in this part. Last part is going to be a discussion on a presented idea and experience sharing.

  • 13:05 – 13:30 – A Guided Tour of Eclipse IoT: 3 Software Stacks for IoT by Benjamin Cabé

Whether you’re looking at the constrained devices that make for the “things” of the IoT, gateways that connect them to the Internet, or backend servers, there’s a lot that one needs to build for creating end-to-end IoT solutions. In this session, we will look at the typical software features that are specific to IoT, and see what’s available in the open source ecosystem (and more specifically Eclipse IoT) to implement them. A live demo of the Eclipse IoT Open Testbed for Asset Tracking will allow the audience to see some of the projects (such as Eclipse Kura, or Eclipse Kapua) in action.

  • 13:45 – 14:10 – Tizen:RT A lightweight RTOS platform for low-end IoT devices by Philippe Coval

The Tizen software platform has been designed to target consumer electronics, since 2013 the OS is powering many products on the market (from smart watches to TVs, cameras or even white goods). Even if this Linux based platform is very flexible, the Linux kernel has minimum size requirements, so Tizen can’t be deployed on constrained devices (ubiquitous microcontrollers).

To also target low end devices part of Tizen’s technology was rebased on NuttX RTOS. Seamless connectivity is still provided by IoTivity, while a new IoT features are becoming available to application developers too, this whole stack is Tizen:RT!

This presentation will give an overview of Tizen ecosystem, and explain how to get started with Tizen:RT using QEmu, SDK, finally an IoT scenario will be demonstrated on trusted system on module ARTIK 055s.

  • 14:25 14:50 – Eclipse IoT FOSS Platform for Cloud Based IoT Solutions by Steffen Evers

It is expected that in the next years billions of devices will be connected to the Internet of things (IoT). Many of them will interact with cloud-based solutions to provide additional services on the devices or in the web. To bring IoT to the next level technologies for supporting cross-domain/cross-vendor solutions are needed. There is already a lot FOSS available to provide a technological base for building IoT solutions (e.g. Kubernetes). However, on top of it, software is needed for the connectivity challenges, support of domain-specific protocols, large scale messaging and device management and integration with existing infrastructure. Eclipse IoT aims to address these needs and provide an FOSS IoT framework that makes IoT development fast and simple. In the last year Eclipse IoT has made a lot of progress and the underlying environment in cloud technology has seen a lot of changes. In addition, upcoming challenges like automated driving and connected vehicles have resulted in new projects for better support for the automotive domain. This talk gives you an overview of major Eclipse IoT projects and illustrates its capabilities with a short demo.

  • 15:05 15:30 – IoT.js – A JavaScript platform for the Internet of Things by Ziran Sun

IoT.js is a JavaScript platform that aims to provide inter-operable services for IoT world. Powered by JerryScript, an ultra-lightweight modular JavaScript engine, the platform is designed to bring the success of Node.js to constrained IoT devices. To address interoperability, IoT.js has provided a Node.js friendly architecture and comes with a subset of Node.js APIs. Since Samsung OSG first presented IoT.js in FOSDEM in 2016, the platform has been through a rapid growth in last couple of years. With a lot active high-quality contributions from the IoT.js and JerryScript open source community, IoT.js has released version 1.0 in July 2017 which presented a rich set of features, hardware and tool supports for developers. In this talk, we are looking at recent developments in IoT.js and share our vision for future plans. The talk is supported by a demo of iot.js running on constrained device seamlessly connects to node.js for third party cloud access.

  • 15:45 – 16:10 – The dark side of Internet of things by Dipesh Monga

With the advent of the Internet of things, monitoring and controlling everything such as coffee maker, lights, TV, Fridge,etc. over the Internet has become a child’s play. But are we really making our lives simpler or diving ourselves in a vast ocean which is getting deeper and deeper? In today’s world where the security of our data of a major concern, the number of websites are always tracking what we search for, what we watch, our location and now when things are limited to only data, adding another dimension i.e. physical entities is really a big question.

From this talk audience will take away an understanding of the privacy concerns related to IoT, and how they may be putting their personal information at risk by connecting my physical entities to the Internet. Is it really safe to connect things to the Internet?

  • 16:30 – 17:00 – Facing the Challenges of Updating Complex Systems by Enrico Jörns

Over the past three years, the growing zoo of Open Source update frameworks made updating an embedded Linux system much easier. But, the availability of a robust update tool solves only one step in the complex chain from a software artifact to an updated and working system on your devices.

Starting with a modern system consisting of a recent bootloader, kernel, init system and update tool, this talk ventures beyond the basic and already solved topics of A/B redundancy, atomicity, or simple update verification.

Enrico will present strategies for creating a robust update chain from automated testing up to full rollout management and show how to solve these challenges with recent Open Source software such as barebox, RAUC, systemd, hawkBit, casync and labgrid. You will learn how to deal with more modular and complex system setups, restricted systems, error recovery, product variants, resigning for deployment, updating the bootloader itself and interaction with verified boot.

  • 17:00 – 18:00 – Multitasking on Cortex-M class MCUs, A deep-dive into the Chromium-EC OS by Moritz Fischer

We’re gonna look at multi-tasking on small Cortex-M class MCUs like the ARM Cortex-M0. After a brief general overview of the Cortex-M0 programming model, exception handling and other basics required, we’ll start our deep-dive into one specific implementation in the Chromium-EC firmware. We’ll look at startup code, how tasks are implemented, how to deal with priorities and peripheral interrupts.

The Chromium-EC firmware is a little (RT)OS that runs (mostly) on ARM cores of the Cortex-M class (M0/M3/M4), and powers Google’s Chromebooks as well as other devices (Project Sulfur SDR). It’s permissive license makes it attractive for (ab)use in other projects, since Kernel and U-Boot integration are already existing.

  • 18:00 – 18:30 –  The Chromium project’s Way to Wayland by Maksim Sisov

Wayland is the most advanced X11-alternative display protocol, shipping today in a variety of desktop and embedded environments. Although the Chromium browser on Linux still defaults to use the X11 window system, there have been efforts to port it to different environments.

This effort happens in various fronts, including the development and stabilization of Ozone, an abstraction layer for graphics and input events, and the transitioning of some ChromeOS-oriented solutions to Linux, for example Chromium’s new “UI service”.

Igalia has been actively contributing to this multi organizational collaboration, aiming at getting a full fledged Chromium browser running natively on Wayland. The work happens on Chromium’s upstream repository so that the greater Chromium community can benefit from it.

  • 18:30 19:00 – GStreamer for tiny devices by Olivier Crête

GStreamer is a complete Open Source multimedia framework, and it includes hundreds of plugins, including modern formats like DASH, HLS or the first ever RTSP 2.0 implementation. The whole framework is almost 150MB on my computer, but what if you only have 5 megs of flash available? Is it a viable choice? Yes it is, and I will show you how.

Starting with simple tricks like only including the necessary plugins, all the way to statically compiling only the functions that are actually used to produce the smaller possible footprint.

Sunday 4, 2018

  • 09:30 10:00 – Programming UEFI for dummies, what I have learned while tweaking FreePascal to output UEFI binaries by Olivier Coursière

With the upcoming end of legacy mode in UEFI firmware on PCs, every alternative and hobbyist operating systems, bare metal programmers and wannabe OS developers will have to deal with UEFI on modern hardware. After presenting the binary format of UEFI applications, I will focus on the use of UEFI APIs through EFI system table and UEFI protocols so you can get started.

  • 10:00 – 10:30 – Rustyarm AKA A project looking at Rust for Embedded Systems by Benedict Gaster (cuberoo_)

Rustyarm is a project in the Physical Computing group at the University of West of England looking at application of Rust on embedded micro controllers. UWE Sense is a new hardware and software platform for IoT, build with ARM micro controllers, Bluetooth LE and LoRaWAN, which runs a software stack written completely in Rust. While UWE Sense is a close to the metal implementation, UWE Audio, a new hardware platform for studying high performance audio using ARM micro controllers, uses Rust to implement a monadic reactive graph, supporting both an offline compiler and and Embedded DSL. UWE Audio uses safe Rust, for example, describing domain clock as generic associated types, providing both compile time guarantees that multiple streams will not be incorrectly sequenced at different sample rates, and the ability to dynamically compile for different parts of the system.

In this talk I will provide a high-level overview of the Rustyarm project, including how using Rust has made this project interesting, but also enabled providing guarantees with respect to the audio scheduler, for example. However, Rust has some short comings in the embedded domain and we provide details on some of these and what we and the wider community are doing to address them. As an example of Rust’s application in the embedded domain we present early work on UWE Audio and hardware and software platform for building digital music instruments, which as already noted is programmed with solely in Rust.

  • 10:30 – 11:00 – How to build an autonomous robot for less than 2K€ by Miika Oja (PuluMan)

Telepresence, Delivery Boy, Security and Follow Me in one PULUrobot. PULUrobot solves the autonomous mobile robotics complexity issue without expensive parts, without compromise. By fearless integration and from-scratch design, our platform can do SLAM, avoid obstacles, feed itself, and carry payload over 100kg, for less than 2000EUR.

Application ecosystem can be born around it, as we offer a ready-made Open Source (GPLv2) solution in a tightly coupled HW-SW codesign. Pulu Robotics Oy was founded in July, 2017, in Finland, to solve our own needs, with an efficient team of three. No one had prior knowledge on robotics.

By studying the market and other startups, we realized the common mistake is to use “robotic modules” as building blocks. They are highly expensive, provide little bang for buck, often are inefficient, and require complex software middleware (such as ROS) as the glue inbetween. Due to our combined background in mechanical, electrical, software and manufacturing design, we took the approach of designing as much as possible by ourselves.

We are now selling the very first generation of robots for the early adopters, hoping to give a kick start to the open source community as soon as possible. Behind the curtains, we are focusing on the development of our next 3D sensor system, which will replace the current scanning 2D lidar with a 360×90 degree full 3D distance data, and do it for the same price we currently pay for the Scanse 2D lidar used in the first small-scale production batch.

  • 11:00 – 11:30 – … like real computers! Making distributions work on single board computers by Andre Przywara

Installing an operating system on single board computers (SBCs or “Fruit-Pis”) is very board specific and requires a lot of hand holding. If at all, standard distributions support only a small number of them explicitly, which leads to a lot of board specific images and distributions. This talk will show how this situation can be improved, to the point where off-the-shelf Linux (or BSD) distributions can be installed on those boards, without those distros knowing about each and every one of them. Key ingredients are standardized firmware interfaces like UEFI, stable device trees and on-board memory like SPI flash. This should make using ARM based SBCs as easy as using (x86) PCs today: like “real computers”. On top of this, ways to simplify and speed up mainline Linux kernel support are explored. Enabling kernel support for new SoCs usually takes a while, especially if the effort is driven by the community. This delays distribution support, up to a point where a certain SoC or board might become slightly dated when it’s finally supported. Using more device tree features and less hardcoded kernel data would reduce the code required to support new SoCs, ideally reaching a point where new SoCs could be at least booted with existing (distribution!) kernels, just by providing the proper device tree blob. This talk describes the idea and gives an example by looking at what can be done on Allwinner SoCs.

  • 11:30 – 12:00 – Booting it successfully for the first time with mainline by Enric Balletbo Serra

While things have gotten a lot better, new hardware bring-up sometimes still feels like pulling teeth. With the right methodology, tools and techniques, a significant amount of time, energy (and sanity) can be saved while enabling a new board to run Linux. In this talk, we’ll discuss the phased process involved in new board bring-up and the challenges it can pose, from reviewing initial schematic design to the successful upstreaming of any necessary bootloader and kernel patches. We’ll also provide some examples of the process based on a board that was recently made compatible with mainline.

  • 12:00 – 12:30 – SITL bringup with the IIO framework, bootstrapping a x86 based drone platform by Bandan Das

This talk aims at an introduction to using the Industrial IO(IIO) framework to initialize sensors and acquire data to feed to a Software in the Loop (SITL) interface of drone software such as iNav/Cleanflight. Most flight controller boards are based on low power ARM microcontrollers and the flight controller software is not usually based on Linux. However, with the availability of increasingly powerful boards with onboard sensors and multicore processors, using a Linux based flight controller software can be used to our advantage. Experimenting with onboard devices and scheduling algorithms can lead to interesting applications with minimal porting overhead to new architectures.

The talk starts with a quick overview of the IIO framework and using it to initialize the drivers for the onboard sensors of the Intel Aero platform, a x86 based flight controller board. Although, not tied to the Aero board in any way, this talk will use this board as an example to describe the onboard sensors and acquire data from them to successfully run a minimal SITL instance. The talk aims to explore how the IIO framework exposes data from these sensors and how users can utilize these interfaces followed by a demo of the setup.

  • 12:30 – 13:00 – Rapid SPI Device Driver Development over USB by Stefan Schmidt

On the quest for a cheap and easy way to connect some simple SPI devices to my laptop it was surprising to not find anything suitable available. The idea is neither new nor innovative and surely there must have been something already.

Maybe the use-case was to special. To connect the SPI device to a Linux laptop over USB in order to develop a SPI kernel driver for it and having a rapid development and test cycle. None of the solutions to access the SPI device over libusb in userspace would work for me. I needed a SPI master controller in kernelspace to work with the variety of devices and kernel subsystems.

After some research I settled on the MCP2210 chip. With its cheap and easy to get development boards and an out-of-tree driver as a good start. Maybe it is also something others are looking for and it is surely worth demonstrating and explaining.

  • 13:00 – 14:00 – Implementing state-of-the-art U-Boot port, 2018 edition by Marek Vasut

This presentation is a practical guide to implementing U-Boot port to a new system from scratch. U-Boot is the de-facto standard bootloader for embedded systems, there is plenty of U-Boot ports, yet vast majority of those are implemented in sub-optimal way. This talk first explains the U-Boot internals, the driver model (DM) and it’s interaction with device tree (DT), as understanding these is vital to understanding the implementation of core subsystems. The core subsystems are explained in detail afterward to allow developers implement drivers the intended way without hacks and workarounds. Unfortunately, not all systems have plenty of resources, but U-Boot caters for those as well. The final part of the talk discusses the U-Boot SPL, the preloader which initializes the hardware, DRAM and starts U-Boot and finer parts of this procedure, which tends to have plenty of pitfalls.

  • 14:00 – 15:00 – Image capture on embedded linux systems by Jacopo Mondi

Image capture is one of the most broad and complex fields of today’s computing applications. Capturing and displaying images with an embedded platform poses additional challenges, introduced by the rapidly increasing complexity of dedicated hardware blocks often found on modern Systems On Chip designed for mobile and industrial computing. Using real world examples of image sensors, connection buses and processing blocks this presentation provides an overview of current industry standard technologies with an introduction to Video4Linux2 kernel framework for driver development and its userspace APIs.

  • 15:00 – 16:00 – ARM64 + FPGA and more: Linux on the Xilinx ZynqMP by Luca Ceresoli

The Xilinx Zynq UltraScale+ MPSoC (aka ZynqMP) is a powerful and complex chip featuring 64-bit cores, 32-bit realtime cores, a large FPGA, a GPU, video codecs and dedicated power management and security units.

The main topics covered will be:

  • Overview of the hardware.
  • Available software support from Xilinx and from the community.
  • How the peculiar CPU+FPGA design effectively allows to design “your own SoC”, with the technical steps to implement this with Linux.
  • Why booting is nontrivial on this SoC and the currently available ways to boot Linux.
  • Handling the H.264/H.265 hardware codecs.
  • GPU support issues.

Focus will be given to how much open source technologies can be used with the ZynqMP SoCs, why this matters, and the current status of open source resources with respect to the alternatives.

  • 16:00 – 16:50 – New GPIO interface for linux user space by Bartosz Golaszewski

Since linux 4.8 the GPIO sysfs interface is deprecated. Due to its many drawbacks and bad design decisions a new user space interface has been implemented in the form of the GPIO character device which is now the preferred method of interaction with GPIOs which can’t otherwise be serviced by a kernel driver. The character device brings in many new interesting features such as: polling for line events, finding GPIO chips and lines by name, changing & reading the values of multiple lines with a single ioctl (one context switch) and many more. In this presentation, Bartosz will showcase the new features of the GPIO UAPI, discuss the current state of libgpiod (user space tools for using the character device) and tell you why it’s beneficial to switch to the new interface.

FOSDEM 2018 will take place at the ULB Solbosch Campus in Brussels, Belgium, attendance is free of charge, and no registration is required.

Embedded Linux Conference & Open Source Summit Europe 2017 Schedule

August 27th, 2017 4 comments

The Embedded Linux Conference & IoT summit 2017 took place in the US earlier this year in February, but there will soon be a similar event with the Embedded Linux Conference *& Open Source Summit Europe 2017 to take up in Europe on October 23 – 25 in Prague, Czech Republic, and the Linux Foundation has just published the schedule. It’s always useful to find out what is being discussed during such events, even if you are not going to attend, so I went through the different sessions, and compose my own virtual schedule with some of the ones I find the most interesting.

Monday, October 23

  • 11:15 – 11:55 – An Introduction to SPI-NOR Subsystem – Vignesh Raghavendra, Texas Instruments India

Modern day embedded systems have dedicated SPI controllers to support NOR flashes. They have many hardware level features to increase the ease and efficiency of accessing SPI NOR flashes and also support different SPI bus widths and speeds.

In order to support such advanced SPI NOR controllers, SPI-NOR framework was introduced under Memory Technology Devices (MTD). This presentation aims at providing an overview of SPI-NOR framework, different types of NOR flashes supported (like SPI/QSPI/OSPI) and interaction with SPI framework. It also provides an overview of how to write a new controller driver or add support for a new flash device.

The presentation then covers generic improvements done and proposed while working on improving QSPI performance on a TI SoC, challenges associated when using DMA with these controllers and other limitations of the framework.

  • 12:05 – 12:45 – Free and Open Source Software Tools for Making Open Source Hardware – Leon Anavi, Konsulko Group

The open source hardware movement is becoming more and more popular. But is it worth making open source hardware if it has been designed with expensive proprietary software? In this presentation, Leon Anavi will share his experience how to use free and open source software for making high-quality entirely open source devices: from the designing the PCB with KiCAD through making a case with OpenSCAD or FreeCAD to slicing with Cura and 3D printing. The talk will also provide information about open source hardware licenses, getting started guidelines, tips for avoiding common pitfalls and mistakes. The challenges of prototyping and low-volume manufacturing with both SMT and THT will be also discussed.

  • 14:20 – 15:00 – Introduction to SoC+FPGA – Marek Vašut, DENX Software Engineering GmbH

In this talk, Marek introduces the increasingly popular single-chip SoC+FPGA solutions. At the beginning, the diverse chip offerings from multiple vendors are introduced, ranging from the smallest IoT-grade solutions all the way to large industrial-level chips with focus on their software support. Mainline U-Boot and Linux support for such chips is quite complete, and already deployed in production. Marek demonstrates how to load and operate the FPGA part in both U-Boot and Linux, which recently gained FPGA manager support. Yet to fully leverage the potential of the FPGA manager in combination with Device Tree (DT) Overlays, patches are still needed. Marek explains how the FPGA manager and the DT Overlays work, how they fit together and how to use them to obtain a great experience on SoC+FPGA, while pointing out various pitfalls.

  • 15:10 – 15:50 – Cheap Complex Cameras – Pavel Machek, DENX Software Engineering GmbH

Cameras in phones are different from webcams: their main purpose is to take high-resolution still pictures. Running preview in high resolution is not feasible, so resolution switch is needed just before taking final picture. There are currently no applications for still photography that work with mainline kernel. (Pavel is working on… two, but both have some limitations). libv4l2 is doing internal processing in 8-bit, which is not enough for digital photography. Cell phones have 10 to 12-bit sensors, some DSLRs do 14-bit depth.

Differences do not end here. Cell phone camera can produce reasonable picture, but it needs complex software support. Auto-exposure / auto-gain is a must for producing anything but completely black or completely white frames. Users expect auto-focus, and it is necessary for reasonable pictures in macro range, requiring real-time processing.

  • 16:20 – 17:00 – Bluetooth Mesh with Zephyr OS and Linux – Johan Hedberg, Open Source Technology Center, Intel

Bluetooth Mesh is a new standard that opens a whole new wave of low-power wireless use cases. It extends the range of communication from a single peer-to-peer connection to a true mesh topology covering large areas, such as an entire building. This paves the way for both home and industrial automation applications. Typical home scenarios include things like controlling the lights in your apartment or adjusting the thermostat. Although Bluetooth 5 was released end of last year, Bluetooth Mesh can be implemented on any device supporting Bluetooth 4.0 or later. This means that we’ll likely see very rapid market adoption of the feature.

The presentation will give an introduction to Bluetooth Mesh, covering how it works and what kind of features it provides. The talk will also give an overview of Bluetooth Mesh support in Zephyr OS and Linux and how to create wireless solutions with them.

  • 17:10 – 17:50 – printk() – The Most Useful Tool is Now Showing its Age – Steven Rostedt, VMware

printk() has been the tool for debugging the Linux kernel and for being the display mechanism for Linux as long as Linux has been around. It’s the first thing one sees as the life of the kernel begins, from the kernel banner and the last message at shutdown. It’s critical as people take pictures of a kernel oops to send to the kernel developers to fix a bug, or to display on social media when that oops happens on the monitor on the back of an airplane seat in front of you.

But printk() is not a trivial utility. It serves many functionalities and some of them can be conflicting. Today with Linux running on machines with hundreds of CPUs, printk() can actually be the cause of live locks. This talk will discuss all the issues that printk() has today, and some of the possible solutions that may be discussed at Kernel Summit.

  • 18:00 – 18:45 – BoF: Embedded Linux Size – Michael Opdenacker, Free Electrons

This “Birds of a Feather” session will start by a quick update on available resources and recent efforts to reduce the size of the Linux kernel and the filesystem it uses.

An ARM based system running the mainline kernel with about 3 MB of RAM will also be demonstrated. If you are interested in the size topic, please join this BoF and share your experience, the resources you have found and your ideas for further size reduction techniques!

Tuesday, October 24

  • 10:55 – 11:35 – Introducing the “Lab in a Box” Concept – Patrick Titiano & Kevin Hilman, BayLibre

Continuous Integration (CI) has been a hot topic for long time. With the growing number of architectures and boards, it becomes impossible for maintainers to validate a patch on all configurations, making it harder and harder to keep the same quality level without leveraging CI and test automation. Recent initiatives like LAVA,, Fuego, (…) started providing a first answer, however the learning curve remains high, and the HW setup part is not covered.

Baylibre, already involved in, decided, as part of the AGL project, to go one step further in CI automation and has developed a turnkey solution for developers and companies willing to instantiate a LAVA lab; called “Lab in a Box”, it aims at simplifying the configuration of a board farm (HW, SW).

Motivations, challenges, benefits and results will be discussed, with a demo of a first “Lab in a Box” instantiation.

  • 11:45 – 12:25 – Protecting Your System from the Scum of the Universe – Gilad Ben-Yossef, Arm Holdings

Linux based systems have a plethora of security related mechanisms: DM-Crypt, DM-Verity, Secure Boot, the new TEE sub-system, FScrypt and IMA are just a few examples. This talk will describe these the various systems and provide a practical walk through of how to mix and match these mechanisms and design them into a Linux based embedded system in order to strengthen the system resilience to various nefarious attacks, whether the system discussed is a mobile phone, a tablet, a network attached DVR, a router, or an IOT hub in a way that makes maximum use of the sometime limited hardware resources of such systems.

  • 14:05 – 14:45 – Open Source Neuroimaging: Developing a State-of-the-Art Brain Scanner with Linux and FPGAs – Danny Abukalam, Codethink

Neuroimaging is an established medical field which is helping us to learn more about how the human brain works, the most complex human organ. This talk aims to cover neuroimaging systems, from hobbyist to professional, and how open source has been used to build state-of-the-art systems. We’ll have a look the general problem area, why open source was a good fit, and some examples of solutions including a commercial effort that we have been involved in bringing to market. Typically these solutions consist of specialist hardware, a bespoke software solutions stack, and a suite to manage and process the vast amounts of data generated during the scan. Other points of interest include how we approached building a maintainable and upgradeable system from the outset. We’ll also talk about future plans for neuroimaging, future ideas for hardware & discuss areas lacking good open source solutions.

  • 14:55 – 15:35 – More Robust I2C Designs with a New Fault-Injection Driver – Wolfram Sang, Renesas

It has its challenges to write code for certain error paths for I2C bus drivers because these errors usually don’t happen on the bus. And special I2C bus testers are expensive. In this talk, a new GPIO based driver will be presented which acts on the same bus as the bus master driver under inspection. A live demonstration will be given as well as hints how to handle bugs which might have been found. The scope and limitations of this driver will be discussed. Since it will also be analyzed what actually happens on the wires, this talk also serves as a case study how to snoop busses with only Free Software and OpenHardware (i.e. sigrok).

  • 16:05 – 16:45 – GStreamer for Tiny Devices – Olivier Crête, Collabora

GStreamer is a complete Open Source multimedia framework, and it includes hundreds of plugins, including modern formats like DASH, HLS or the first ever RTSP 2.0 implementation. The whole framework is almost 150MB on my computer, but what if you only have 5 megs of flash available? Is it a viable choice? Yes it is, and I will show you how.

Starting with simple tricks like only including the necessary plugins, all the way to statically compiling only the functions that are actually used to produce the smaller possible footprint.

  • 16:55 – 17:35 – Maintaining a Linux Kernel for 13 Years? You Must be Kidding Me. We Need at Least 30? – Agustin Benito Bethencourt, Codethink Ltd

Industrial grade solutions have a life expectancy of 30+ years. Maintaining a Linux kernel for such a long time in the open has not been done. Many claim that is not sustainable, but corporations that build power plants, railway systems, etc. are willing to tackle this challenge. This talk will describe the work done so far on the kernel maintenance and testing front at the CIP initiative.

During the talk it will be explained how we decide which parts of the kernel to cover – reducing the amount of work to be done and the risk of being unable to maintain the claimed support. The process of reviewing and backporting fixes that might be needed on an older branch will be briefly described. CIP is taking a different approach from many other projects when it comes to testing the kernel. The talk will go over it as well as the coming steps. and the future steps.

Wednesday, October 24

  • 11:05 – 11:45 – HDMI 4k Video: Lessons Learned – Hans Verkuil, Cisco Systems Norway

So you want to support HDMI 4k (3840×2160) video output and/or video capture for your new product? Then this is the presentation for you! I will describe the challenges involved in 4k video from the hardware level, the HDMI protocol level and up to the kernel driver level. Special attention will be given to what to watch out for when buying 4k capable equipment and accessories such as cables and adapters since it is a Wild, Wild West out there.

  • 11:55 – 12:35 – Linux Powered Autonomous Arctic Buoys – Satish Chetty, Hera Systems 

In my talk/presentation, I cover the technical, and design challenges in developing an autonomous Linux powered Arctic buoy. This system is a low cost, COTS based, extreme/harsh environment, autonomous sensor data gathering platform. It measures albedo, weather, water temperature and other parameters. It runs on a custom embedded Linux and is optimized for efficient use of solar & battery power. It uses a variety of low cost, high accuracy/precision sensors and satellite/terrestrial wireless communications.

I talk about using Linux in this embedded environment, and how I address and solve various issues including building a custom kernel, Linux drivers, frame grabbing issues and results from cameras, limited power challenges, clock drifts due to low temperature, summer melt challenges, failure of sensors, intermittent communication issues and various other h/w & s/w challenges.

  • 14:15 – 14:55 – Linux Storage System Bottleneck for eMMC/UFS – Bean Huo & Zoltan Szubbocsev, Micron

The storage device is considered a bottleneck to the system I/O performance. This thinking drives the need for faster storage device interfaces. Commonly used flash based storage interfaces support high throughputs, eg. eMMC 400MB/s, UFS 1GB/s. Traditionally, advanced embedded systems were focusing on CPU and memory speeds and these outpaced advances in storage speed improvements. In this presentation, we explore the parameters that impact I/O performance. We describe at a high level how Linux manages I/O requests coming from user space. Specifically, we look into system performance limitations in the Linux eMMC/UFS subsystem and expose bottlenecks caused by the software through Ftrace. We show existing challenges in getting maximum performance of flash-based high-speed storage device. by this presentation, we want to motivate future optimization work on the existing storage stack.

  • 15:05 – 15:45 – New GPIO Interface for User Space – Bartosz Golaszewski

Since Linux 4.8 the GPIO sysfs interface is deprecated. Due to its many drawbacks and bad design decisions a new user space interface has been implemented in the form of the GPIO character device which is now the preferred method of interaction with GPIOs which can’t otherwise be serviced by a kernel driver. The character device brings in many new interesting features such as: polling for line events, finding GPIO chips and lines by name, changing & reading the values of multiple lines with a single ioctl (one context switch) and many more. In this presentation, Bartosz will showcase the new features of the GPIO UAPI, discuss the current state of libgpiod (user space tools for using the character device) and tell you why it’s beneficial to switch to the new interface.

  • 16:15 – 16:55 – Replace Your Exploit-Ridden Firmware with Linux – Ronald Minnich, Google

With the WikiLeaks release of the vault7 material, the security of the UEFI (Unified Extensible Firmware Interface) firmware used in most PCs and laptops is once again a concern. UEFI is a proprietary and closed-source operating system, with a codebase almost as large as the Linux kernel, that runs when the system is powered on and continues to run after it boots the OS (hence its designation as a “Ring -2 hypervisor”). It is a great place to hide exploits since it never stops running, and these exploits are undetectable by kernels and programs.

Our answer to this is NERF (Non-Extensible Reduced Firmware), an open source software system developed at Google to replace almost all of UEFI firmware with a tiny Linux kernel and initramfs. The initramfs file system contains an init and command line utilities from the u-root project, which are written in the Go language.

  • 17:05 – 17:45 – Unikernelized Real Time Linux & IoT – Tiejun Chen, Vmware

Unikernel is a novel software technology that links an application with OS in the form of a library and packages them into a specialized image that facilitates direct deployment on a hypervisor. But why these existing unikernels have yet to gain large popularity broadly? I’ll talk what challenges Unikernels are facing, and discuss exploration of if-how we could convert Linux as Unikernel, and IoT could be a valuable one of use cases because the feature of smaller size & footprint are good for those resource-strained IoT platforms. Those existing unikernels are not designed to address those IoT characters like power consumption and real time requirement, and they also doesn’t support versatile architectures. Most existing Unikernels just focus on X86/ARM. As a paravirtualized unikenelized Linux, especially Unikernelized Real Time Linux, really makes Unikernels to succeed.

If you’d like to attend the real thing, you’ll need to register and pay a registration fee:

  • Early Registration Fee: US$800 (through August 27, 2017)
  • Standard Registration Fee: US$950 (August 28, 2017 – September 17, 2017)
  • Late Registration Fee: US$1100 (September 18, 2017 – Event)
  • Academic Registration Fee: US$200 (Student/Faculty attendees will be required to show a valid student/faculty ID at registration.)
  • Hobbyist Registration Fee: US$200 (only if you are paying for yourself to attend this event and are currently active in the community)

There’s also another option with the Hall Pass Registration ($150) if you just want to network on visit with sponsors onsite, but do not plan to attend any sessions or keynotes.

A Look at Three Options to Develop Real-Time Linux Systems on Application Processors – HMP, Real-Time Linux and Xenomai

October 15th, 2016 8 comments

This is a guest post by written by Guilherme Fernandes, Raul Muñoz, Leonardo Veiga, Brandon Shibley, all working for Toradex.


Application processor usage continues to broaden. System-on-Chips, usually powered by ARM Cortex-A cores, are taking over several spaces where small ARM Cortex-M, and other microcontroller devices, have traditionally dominated. This trend is driven by several facts, such as:

  • The strong requirements for connectivity, often related to IoT and not only from a hardware point of view, but also related to software, protocols and security
  • The need for highly interactive interfaces such as multi-touch, high resolution screens and elaborate graphical user interfaces;
  • The decreasing price of SoCs, as consequence of its volume gain and new production capabilities.

Typical cases exemplifying the statement above are the customers we see every day starting a product redesign upgrading from a microcontroller to a microprocessor. This move offers new challenges as the design is more complicated and the operating system abstraction layer is much re complex. The difficulty of hardware design using an application processor is overcome by the use of reference designs and off-the-shelf alternatives like computer-on-modules or single board computers. On the operating system layer, the use of embedded Linux distributions is widespread in the industry. An immense world of open source tools is available simplifying the development of complex and feature rich embedded systems. Such development would be very complicated and time consuming if using microcontrollers. Despite all the benefits, the use of an operating system like Linux still raises a lot of questions and distrust when determinism and real-time control application topics are addressed.

A common approach adopted by developers is the strategy of separating time-critical tasks and regular tasks onto different processors. Hence, a Cortex-A processor, or similar, is typically selected for multimedia and connectivity features while a microcontroller is still employed to handle real-time, determinism-critical tasks. The aim of this article is to present some options developers may consider when developing real-time systems with application processors. We present three possible solutions to provide real-time capability to application processor based designs.

Heterogeneous Multicore Processing

The Heterogeneous Multicore Processing (HMP) approach is a hardware solution. Application processors like the NXP i.MX7 series, the NXP i.MX6SoloX and the upcoming NXP i.MX8 series present a variety of cores with different purposes. If we consider the i.MX7S you will see a dual core processor composed of a Cortex-A7 core @ 800MHz side-by-side with a Cortex-M4 core @ 200MHz. The basic idea is that user interface and high-speed connectivity are implemented on an abstracted OS like Linux with the Cortex-A core while, independently and in parallel, executing control tasks on a Real-Time OS, like FreeRTOS, with the Cortex-M core. Both cores are able to share access to memory and peripherals allowing flexibility and freedom when defining which tasks are allocated to each core/OS. Refer to Figure 1.

NXP i.MX7 Block Diagram (Click to Enlarge)

Figure 1 – NXP i.MX7 Block Diagram (Click to Enlarge)

Some of the advantages of using the HMP approach are:

  • Legacy software from microcontrollers can be more easily reused;
  • Firmware update (M4 core) is simplified as the firmware may be a file at the filesystem of the Cortex-A OS;
  • Increased flexibility of choosing which peripherals will be handled by each core. Since it is software defined, future changes can be made without changing hardware design.

More information on developing applications for HMP-based processors are available at these two articles:

Toradex, Antimicro and The Qt Company collaboratively built a robot showcasing this concept. The robot – named TAQ – is an inverted pendulum balancing robot designed with the Toradex Computer on Module Colibri iMX7. The user interface is built upon Linux with the QT framework running on the Cortex-A7 and the balancing/motor control is deployed on the Cortex-M4. Inter-core communication is used to remote control the robot and animate its face as seen in the short video below.

Real-Time Linux

The second approach we present in this article is software related. Linux is not a real-time operating system, but there are some initiatives which have greatly improved the determinism and timeliness of Linux. One of these efforts is the Real-Time Linux project. Real-Time Linux is a series of patches (PREEMPT_RT) aimed at adding new preemption options to the Linux Kernel along with other features and tools to improve its suitability for real-time tasks. You can find documentation on applying the PREEMPT_RT patch to the Linux kernel and developing applications for it at the official Real-Time Linux Wiki (formerly here).

We did some tests using the PREEMPT_RT patches on a Colibri iMX6DL to exemplify the improvement in real-time performance. The documentation on preparing the Toradex Linux image to deploy the PREEMPT_RT patch is available at this link. We developed a simple application which toggles a GPIO at a 2.5KHz (200µs High / 200µs Low). The GPIO output is connected to a scope where we measure the resulting square wave and evaluate the real output timings. The histograms below show the comparison between the tests on a standard Linux kernel configured for Voluntary Preemption (top) and a PREEMPT_RT patched Linux kernel configured for Real-time Preemption (bottom). The x-axis represents the period of the square wave sample and the y-axis represents the number of samples which measured with such a period. The table below the chart presents the worst and average data.

Click to Enlarge

Figure 2: Histogram of the square wave generated using the standard Kernel (top) and Preempt-RT kernel (bottom) – Click to Enlarge



Smallest (µs)

Worst Case for 99% of  Samples (µs)

Worst Case (µs)

Median (µs)

Average (µs)

Default Kernel














Table 1: Comparison between Default Kernel and real-time Kernel when generating a square wave.

An example software system using the PREEMP_RT patch is provided by Codesys Solutions. They rely on the Real-Time Linux kernel, together with the OSADL (Open Source Automation Development Lab), to deploy their software PLC solution which is already widespread throughout the automation industry across thousands of devices. The video below presents the solution running on a Apalis iMX6Q.


Xenomai is another popular framework to make Linux a real-time system. Xenomai achieves this by adding a co-kernel to the Linux kernel. The co-kernel will handle time-critical operations and will have higher priority than the standard kernel. To use the real-time capabilities of Xenomai the real-time APIs (aka libcobalt) must be used to interface user-space applications with the Cobalt core, which is responsible for ensuring real-time performance.


Figure 3: Dual Core Xenomai Configuration

Documentation on how to install Xenomai on your target device can be found at the Xenomai website. Additionally, there is a variety of Embedded Hardware which is known to work as indicated in the hardware reference list, which includes the whole NXP i.MX SoC series.

To validate the use of Xenomai on the i.MX6 SoC we also developed a simple experiment. The target device was the Colibri iMX6DL by Toradex. We ran the same test approach as described above for the Real-Time Linux extension. Some parts of the application code used to implement the test are presented below to highlight the use of Xenomai APIs.

The results comparing Xenomai against a standard Linux kernel are presented in the chart below. Once again, the real-time solution provides a clear advantage – this time with even greater distinction – over the time-response of the standard Linux kernel.

Click to Enlarge

Figure 3: Histogram of the square wave generated using the standard Kernel (top) and Xenomai (bottom) – Click to Enlarge



Smaller (µs)

Worst Case for 99% of Samples (µs)

Worst Case (µs)

Median (µs)

Average (µs)

Default Kernel







Xenomai Implementation







Table 2: Comparison between Default Kernel and Xenomai implementation when generating a square wave.


This article presented a brief overview of some solutions available to develop real-time systems on application processors running Linux as the target operating system. This is a starting point for developers who are aiming to use microprocessors and are concerned about real-time control and determinism.

We presented one hardware-based approach, using Heterogeneous Multicore Processing SoCs and two software based approaches namely: Linux-RT Patch and Xenomai. The results presented do not intend to compare operating systems or real-time techniques. Each of them has strong and weak points and may be more or less suitable depending on the use case.

The primary takeaway is that several feasible solutions exist for utilizing Linux with application processors in reliable real-time applications.

ARM Unveils Cortex-R52 ARMv8-R CPU Core for Safety-Critical Systems

September 20th, 2016 1 comment

ARM has introduced their very first ARMv8-R real-time 32-bit CPU core with Cortex-R52 designed for safety-critical applications in the automotive, industrial and health-care markets. It has been designed to address higher workloads with increased performance (up to 35%) compared to Cortex-R5 processor.

Click to Enlarge

Click to Enlarge

The processor should be used in systems capable of fulfilling IEC 61508 SIL 3 and ISO 26262 ASIL D functional safety requirements. ARM explains the new processor address both random errors for example bit flipping from radiation, and systemic errors more related to software or design faults.


The latter can be addresses with the right development processes, including following aforementioned functional safety standards, but random errors require some extra hardware features such as ECC memory, or dual core lock step processors, where instructions are run on two processors simultaneously and results compared.

Normally, the whole software stack must be validated and certified on safety-critical systems, even for part of the code that may not be safety-critical. This is a time-consuming and costly endeavor however, and as software becomes ever more complex becomes an issue. So Cortex R52 cores also implement a Level 2 MPU running monitor or hypervisor software, which can help separating safety code, critical safety code and non-safety code.

arm-processor-real-time-coreCortex-R52 cores would typically be used in conjunction with Cortex-A cores running non-safety code, and offering higher performance, throughput, and more peripherals. Some current processors featuring Cortex-Rxx cores include Xilinx Zynq UltraScale+ MPSoC (Cortex-R5), and Renesas R-Car H3 automotive SoC (Cortex-R7).

You may want to visit ARM Cortex-R52 product page for a few more details.

Embedded Linux Conference Europe 2014 Schedule – IoT, ARM vs x86, Optimization, Power Management, Debugging…

August 21st, 2014 2 comments

The Embedded Linux Conference Europe (ELC 2014), CloudOpen, and LinuxCon Europe will jointly take place at the Congress Centre Düsseldorf, in Germany on October 13 – 15, 2014. The 3-day events will consists of keynotes, presentations, and tutorials. Each day will open with two or three keynotes by speakers including  Jim Zemlin (Executive Director, Linux Foundation), and Jono Bacon (XPRIZE), followed by presentation and tutorials. There will be 45 presentations for ELCE, 58 for LinuxCon, and 47 for CloudOpen, I’ll make a virtual schedule with a few sessions part of the Embedded Linux Conference Europe “track”.


Monday, October 13

When faced with a performance problem, the initial steps towards a solution include identifying the sections of code responsible and the precise reasons they are time-consuming. To this end, the ‘perf’ profiling tools provide valuable insight into the characteristics of a program. The presentation will show, using real-world examples, how the ‘perf’ tools can be used to pinpoint the parts of a program in need of optimization.

It’s not uncommon to produce embedded Linux based devices that end up with long and inconvenient boot times – yet eliminating boot time delays can be difficult and time consuming. Furthermore once a minimal boot time has been achieved it’s often just as difficult to maintain it through subsequent software development.

In this presentation, Andrew unfolds 12 keys lessons learned in his experience of boot time reduction. These lessons provide an insight into the common causes of boot time delays, why they are present and how they can be overcome. In describing these lessons Andrew will also take you on a journey that indicates why file system benchmarks should probably be ignored (with respect to boot time reduction) and a journey that illustrates that the Linux kernel is rarely the worst offender for boot delays.

With the introduction of Bluetooth Smart (aka Low Energy), the ubiquity of Bluetooth is more and more present. Millions of devices support Bluetooth Low Energy and with Bluetooth 4.1 specification, they are ready for the Internet of Things. This presentation will give an overview of Bluetooth Low Energy, and its usage for the Internet of Things. It will also introduce 6loWPAN over Bluetooth and show the possibilities this opens for Linux.

With experience developing community based open hardware for both the ARM based PandaBoard project and the x86 based MinnowBoard project, this presentation will provide a detailed comparison of the pros and cons of each platform with highlights of what each platform can learn from the other. Not only limited to the hardware aspect of the platforms, but also discuss community, software, corporate and general embedded aspects.

For almost as long as there have been deployments of Linux, there has been someone wondering “how can I get the device started quicker?” and “how do I configure some redundancy, easily, in case something goes wrong?”. And for the longest time, the answer has been “hack this and this and that” or “hire these consultants, they have done it before”. In this presentation, Tom will show what you need to turn on and the prep work required for, getting a lot of those items out of the box in U-Boot, what the hardware (and/or ROM) needs to do, and the what works is left going forward.

Got a question, comment, gripe, praise, or other communication for the Yocto Project and/or OpenEmbedded? Or maybe you’d just like to learn more about these projects and their influence on the world of embedded Linux? Feel free to join us for an informal BoF.

Tuesday, October 14

While user experiences are increasingly moving to 3D, rendering of 2D content remains at the core of how we interact with computer applications today. Skia is an open-source project maintained by Google whose goal is to bring the best 2D graphics library to a variety of targets, from mobile to desktop and embedded. Skia is used in highly popular projects like Mozilla Firefox, the Chromium browser and Android.

This talk will introduce Skia to developers and users, giving an overview of its design, architecture and features. It will also discuss briefly how hardware acceleration improves performance of Skia in the context of new devices, form-factors and the industry shift to mobile; with focus set on Linux and Android platforms.

The 4.4 KitKat release includes the results of “Project Svelte”: a set of tweaks to the operating system to make it run more easily on devices with around 512 MB RAM. This is especially important for people working with Android Wearables and “Embedded Android”, that is, implementing Android on devices at the lower end of the Android ecosystem. A large part of the problem is knowing how much RAM is really being used. Android offers a variety of tools for the purpose: procrank, procmem, meminfo and procstats, which Chris covers in the first part of the talk. In the second part, he takes a real-world example and show the practical steps you can take to optimize memory use including tuning the size of the Dalvik heap, enabling KSM (Kernel samepage merging) and swap to zRAM.

Android has relied from its early days on the Linux kernel for sandboxing the processes it runs. Yet, the permission model presented to app developers is significantly different from the Unix permission model. What’s the relationship between those two models? How is Android’s app security framework tied to the Linux kernel’s security model? More recently, Android has started using SELinux and has been extended by SEAndroid to support similar functionality. How is SELinux used by Android and what is SEAndroid about? Furthermore, how does Android provide support for multiple users?

This talk will explore Android’s security model in great detail and explain how the functionality found in the kernel is used to isolate user processes and the SE enhancements are leveraged by Android. As we’ll see, there are quite a few moving parts in Android’s security model.

Since last year, Free Electrons has been working on supporting the SoCs from Allwinner, a Chinese SoC vendor, in the mainline kernel. These SoCs are cheap, wide-spread, backed by a strong community and, until last year, only supported by an out-of-tree kernel. Through this talk, Maxime will share the status of this effort: the status a year ago, what solutions were in place, where we are currently, and what to expect from the future. He will also focus on the community around these SoCs, the work that is done there, etc.

Enlightenment Foundation Library is a set of libraries designed to use the full potential of any hardware to do great UI. It has been designed with the embedded devices in mind, but it is a desktop class toolkit. Being done in C, it is providing a stable API/ABI, high efficiency, low memory and low battery usage for all kind of Linux devices. Enabling development of modern UI adapted to any hardware that run Linux. These are the reason why Samsung uses it in its Tizen devices. This talk, after a short overview of what this libraries cover, will focus on this year improvement, and where it is heading. It will also be an opportunity to learn about project around EFL that will help people develop product with it. And it would also be a good opportunity to see where EFL are used with some real use case.

Wednesday, October 15

A major issue the community faces is the lack of power measurement (PM) instrumentation, coupled with poor integration: development boards not designed for it, expensive high-precision lab equipment not accessible to hobbyists (plus limited Linux support), limited low-cost solutions (precision, sampling rate) to monitor high-performance SoC (System On Chips) platforms (e.g. smartphones, tablets, IoT, …). After a brief introduction to the problematic (PM techniques, sense resistor / ADC selection, …) and a comparative study of existing solutions, this presentation will focus on a new upcoming initiative to close these gaps and bring a full-blown multi-channel but low-cost power (and temperature) measurement equipment to the community, including the definition of an open standard PM connector. After having covered motivations, challenges, key decisions, a live demo will close the talk.

In 2013, at the Embedded Linux Conference in Europe in Edinburgh, there was a race between a dog and a blimp. It was said that despite the dogs win, that the blimp had participated in the miracle of flight. In 2014, John wants to show that the brains of that dog can be transplanted and that it too, can participate in the miracle of flight. The talk is mainly targeting taking an off the shelf embedded platform, Minnowboard Max, and it’s use in UAVs, specifically quad-copters. With the ability to do real time computer vision, as well as various GPIO capabilities he will explore the directions that significantly more autonomous UAVs can take with Linux and embedded platforms using, mostly, off the shelf components.

There have been many presentations on what a device tree looks like and how to create a device tree. This talk instead examines how the Linux kernel uses a device tree. Topics include the kernel device tree framework, device creation, resource allocation, driver binding, and connecting objects. Troubleshooting will consider initialization, allocation, and binding ordering; kernel configuration; and driver problems.

Providing real-time capabilities to a general purpose operating system is an outstanding technical problem, and Linux Preempt-RT has been developed for 10 years for this goal. In this presentation, Jim proposes a lightweight open source para-virtualization layer, called “rtmux”, using resource-multiplexing techniques to provide a highly deterministic RT environment for Linux/ARM. Typically, less than 500 lines modification against Linux kernel are required to enable rtmux accompanied by POSIX/PSE51 compatible runtime.

During the last 2.5 years, a team of engineers at Free Electrons has been involved in mainlining the support for several ARM processors from Marvell, converting the not-so-great vendor-specific BSP into mainline quality code progressively merged upstream. This effort of several hundreds working days, has led to the integration of hundreds of patches in the kernel. Through this talk, Thomas will share some lessons learned regarding this mainlining effort, which could be useful to other engineers involved in ARM SoC support, as well as detail the steps Free Electrons engineers have gone through, the mistakes made and how they’ve been solved, as well as their overall experience on this project.

To make your own schedule matching your interests, you can check out the events’ program.

To attend the conference, you can register online.

The fees are listed as follows:

  • All-access Registration Fee – $600 until August 22 (tomorrow), $750 until October 2, and $850 afterwards
  • Attendee Networking Pass Registration – No access to conference sessions. $250 until August 22, $300 afterwards.
  • Student Registration Fee – $200 (valid student id required).
  • Registration Discount Scholar – $300. For active open source community members who can’t be sponsored by their company. .

Fees are significantly higher than last year, because there are only all-in-one (ELCE, CloudOpen and LinuxCon )options, and you can’t simply register to one single event.

Understanding PREEMPT_RT (The Real-Time Patch) – ELCE 2012

January 16th, 2013 No comments

Steven Rostedt, working at Red Hat, talks about Real-Time Linux at the Embedded Linux Conference Europe, in Spain on November 6, 2012.


The real-time patch (which provides CONFIG_PREEMPT_RT), has been around since 2005. Started by Ingo Molnar and maintained by Thomas Gleixner and several others, it has grown from a hobby RTOS into a very serious contender. Several distributions (Red Hat, SuSE, Debian, Ubuntu) supply a kernel version that includes this patch. The embedded world has started adding the -rt patch to their own devices that they ship. But do the embedded developers understand what the -rt patch supplies? Programming for real time, and especially when writing kernel code requires special knowledge to avoid real time traps. This talk will explain what the real time patch provides and special programming tips that will ensure embedded developers will get the best from their devices.

Real-Time Linux Option in Make menuconfig: "Fully Preempt Linux Kernel (RT)"

Real-Time Linux Option in Make menuconfig: “Fully Preemptible Kernel (RT)”

He goes through the following key points during the presentation:

  • Real-time OS definition – Deterministic, does not mean fast (but still nice), meet deadlines.
  • Goal of PREEMP_RT – 100% Preemptible kernel and quick reaction
  • Different levels of preemption in Linux:
    • No preemption – Do as most possible with as little scheduling overhead. Use for server in Linux 2.4
    • Voluntary preemption – Schedule only at “preemption points”
    • Preemptible Kernel – CONFIG_PREEMPT. Preempt anywhere except within spin_locks
    • Preemptible Kernel (Basic RT) – For debugging, it will most probably go away…
    • Fully Preemptible Kernel – PREEMPT_RT_FULL. Preempts everywhere except from preempt_disable and interrupts disabled.
  • Details of PREEMPT_RT in the Linux kernel – priorities, spin_locks, interrupts, threaded interrupts, etc…

You can also download the slides for this tutorial/presentation. You may also want to access the source code via the Git repo, or get the PREEMPT_RT patches at Full details cane be found on the Real-Time Linux Wiki.