The initial target was making Zephyr’s clocks synchronize with external Grand Masters. Our focus was getting it to work on Microchip SAM E70 Xplained. At that time, the platform already had a Zephyr port (including the Ethernet driver), but it lacked drivers for the PTP clock. Terabyte wifi adapter w777mi driver. Terabyte wifi adapter w777mi driver Sign In. Page 1 of 3 Page 1 of 3.

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Topics: Open networking, Open source tools

Solving problems that require real-time calculations and precise control typically calls for using an RTOS. While we have been working with a wide variety of RTOSs for various applications (like Contiki-NG for IoT, RTEMS for space applications, eCos for satellite equipment, FreeRTOS in many other fields etc), Antmicro’s RTOS of choice these days has been Zephyr, a Linux-Foundation driven, well-structured, vendor-independent and scalable real-time OS. We’ve ported and adapted Zephyr to many platforms, encouraged its use as a standard on RISC-V, promoted it in less standard contexts like FPGA devices.

So if you have a single device with a real-time requirement, typically it’s not that hard to decide how to approach the problem - just use Zephyr!

The problem starts when there are multiple heterogeneous devices that have to communicate in a standardised and robust way, performing a complex operation involving a network protocol while never leaving the “real-time” world. Scenarios like this are typical in the aerospace, automotive, robotics industries, and increasingly those industries are looking to reuse technologies known from the commercial/consumer market to leverage the massive scale offered by omnipresent, commodity tech.

For your everyday use case, the easiest way to connect multiple devices is of course Ethernet, but plain old Ethernet does not list real-time capabilities in its dictionary - how then can it be used in a real-time use case?

The set of standards that define Time Sensitive Networking is the answer to that problem. Leveraging the physical and logical foundations of Ethernet and extends it to cover real-time use cases by defining different aspects of time sensitive communication: clock synchronization, traffic shaping, scheduling, fault tolerance etc.

TSN seems then like a good fit, and sure enough, open source support for TSN is widely available in Linux. In the RTOS world however, there has previously not existed a proper implementation of TSN, readily available and tested on real hardware platforms, well, not until Zephyr 1.13!

Initial work: towards a TSN implementation in Zephyr

As a member of the Zephyr Project, Antmicro is always excited to add new functionalities to the OS, especially in fields that open it up for adoption in new use cases. Here, we were happy to work with another Zephyr project member, Intel on getting gPTP support added to Zephyr. “gPTP” stands for “generic Precision Time Protocol” and is responsible for clock synchronization. When we joined the project it was already in progress, but far from being finished. We implemented the missing state machines and fixed various bugs in the existing code.

The initial target was making Zephyr’s clocks synchronize with external Grand Masters.

Our focus was getting it to work on Microchip SAM E70 Xplained. At that time, the platform already had a Zephyr port (including the Ethernet driver), but it lacked drivers for the PTP clock.

The TSN support was also tested on the NXP FRDM K64F development platform which also has a Zephyr port and hardware timestamping support.

After initial support was done and merged, we proceeded with configuring Zephyr nodes as Grand Masters, as well as ensuring operational Zephyr-to-Zephyr clock synchronization.

Qav: an important part of TSN

PTP is only a part of Time Sensitive Networking. Another important part of TSN is queue management.

The platform of our choice (SAM E70 Xplained) has multiple hardware queues built into its MAC controller, which allowed us to use the same platform to extend Zephyr’s TSN capabilities.

Antmicro implemented support for credit-based shaper algorithms in Zephyr, which are described in the 802.1Qav standard.

The work in that area required us to design an API to manage the Qav-capable Ethernet queues. Through this API/management interface, we made it possible to set and read various parameters, like idle slope, delta bandwidth, traffic class, etc.

Additionally, some status parameters were implemented. These are now shown in the regular networking shell in Zephyr for the supported network interfaces.

Running a basic Zephyr gPTP sample application

To find out how to run the basic gPTP sample, please refer to Zephyr’s official documentation.

More general info about the gPTP stack implementation can be found in a dedicated chapter.

Testing in Renode Cloud Environment

A network stack plays a critical role in an operating system like Zephyr. It is also constantly under very heavy development by various parties. Our work on the TSN/gPTP support was heavily influenced by all the changes in the networking subsystem. As can be expected in large development campaigns, these completely unrelated things would break our implementation repeatedly.

The reason for that was lack of more sophisticated testing of the setup. Sure, there were multiple unit tests which directly tested our stack implementation, but Time Sensitive Networking can be broken by seemingly minor changes in other parts of the networking stack.

Obviously, network protocol testing is difficult. You can either use synthetic tests that easily get outdated and don’t really reflect real life scenarios or you can create complicated physical network setups connected to a CI system - which is costly, difficult to maintain and creates only a single, static configuration.

A much better, more scalable solution is to use simulation. With Antmicro’s Renode open source simulation framework you can create script-defined complex configurations, allowing you to verify virtually every scenario imaginable.

In Renode’s 1.7 release, Antmicro added support for the SAM E70 platform, along with Ethernet with gPTP capabilities. With these new features we were able to create a CI setup testing upstream Zephyr in a virtual environment.

And thanks to an integration with the Robot Framework, it’s very easy to create new test cases in Renode. That’s why, for Zephyr, we decided to create a suite of tests verifying a range of aspects of a single application.

This lines up perfectly with the introduction of Renode Cloud Environment - a new CI system introduced by Antmicro, that you’ll be able to read about more on our blog soon. Here is a sneak peek of the TSN testing setup running in RCE.

First, Renode verifies if the board sends a PTP packet, which means that the PTP stack is started properly. Next, we analyze its reception and the proper reaction from the recipient’s OS. We analyze whether the compile-time configuration of the PTP stack is properly reflected in its runtime, and the highest level properties: whether the correct Grand Master node has been selected and whether the slave nodes are properly synchronizing their clocks.

The whole testing setup can be easily recreated with upstream Renode and Zephyr. For instructions, please refer to the TSN testing tutorial.

Building a TSN system?

If you’d like to use TSN is your system, and feel that an RTOS like Zephyr is a good fit for your needs, be sure to reach out to us at contact@antmicro.com - we’d be happy to help you apply TSN on existing and new hardware, and perhaps in simulation, for real-world use cases!

The Zephyr OS is based on a small-footprint kernel designed for use onresource-constrained and embedded systems: from simple embedded environmentalsensors and LED wearables to sophisticated embedded controllers, smartwatches, and IoT wireless applications.

The Zephyr kernel supports multiple architectures, including ARM Cortex-M, Intelx86, ARC, NIOS II, Tensilica Xtensa and RISC-V 32. The full list of supportedboards can be found here.

Licensing¶

Zephyr is permissively licensed using the Apache 2.0 license(as found in the LICENSE file in theproject’s GitHub repo). There are someimported or reused components of the Zephyr project that use other licensing,as described in Licensing of Zephyr Project components.

Distinguishing Features¶

Zephyr offers a large and evergrowing number of features including:

Zephyr offers a number of familiar services for development:

• Multi-threading Services for cooperative, priority-based,non-preemptive, and preemptive threads with optional round robintime-slicing. Includes POSIX pthreads compatible API support.
• Interrupt Services for compile-time registration of interrupt handlers.
• Memory Allocation Services for dynamic allocation and freeing offixed-size or variable-size memory blocks.
• Inter-thread Synchronization Services for binary semaphores,counting semaphores, and mutex semaphores.
• Inter-thread Data Passing Services for basic message queues, enhancedmessage queues, and byte streams.
• Power Management Services such as tickless idle and an advanced idlinginfrastructure.

Zephyr provides a comprehensive set of thread scheduling choices:

• Cooperative and Preemptive Scheduling
• Earliest Deadline First (EDF)
• Meta IRQ scheduling implementing “interrupt bottom half” or “tasklet”behavior
• Timeslicing: Enables time slicing between preemptible threads of equalpriority
• Multiple queuing strategies:
  • Simple linked-list ready queue
  • Red/black tree ready queue
  • Traditional multi-queue ready queue

Implements configurable architecture-specific stack-overflow protection,kernel object and device driver permission tracking, and thread isolationwith thread-level memory protection on x86, ARC, and ARM architectures,userspace, and memory domains.

For platforms without MMU/MPU and memory constrained devices, supportscombining application-specific code with a custom kernel to create amonolithic image that gets loaded and executed on a system’s hardware. Boththe application code and kernel code execute in a single shared addressspace.

Download Zephyr Port Devices Drivers

Download Zephyr Port Devices Driver Windows 7

Bluetooth 5.0 compliant (ESR10) and Bluetooth Low Energy Controller support(LE Link Layer). Includes BLE Mesh and a Bluetooth qualification-ready BLEcontroller.

• Generic Access Profile (GAP) with all possible LE roles.
• GATT (Generic Attribute Profile)
• Pairing support, including the Secure Connections feature from Bluetooth4.2
• Clean HCI driver abstraction
• Raw HCI interface to run Zephyr as a Controller instead of a full Hoststack
• Verified with multiple popular controllers
• Highly configurable

Mesh Support:

• Relay, Friend Node, Low-Power Node (LPN) and GATT Proxy features
• Both Provisioning bearers supported (PB-ADV & PB-GATT)
• Highly configurable, fitting in devices with at least 16k RAM

Getting Started¶

To start developing Zephyr applications refer to the Getting Started Guidein the Zephyr Documentation pages.A brief introduction to Zephyr can be found in the Zephyr Introductionpage.

Community Support¶

The Zephyr Project Developer Community includes developers from memberorganizations and the general community all joining in the development ofsoftware within the Zephyr Project. Members contribute and discuss ideas,submit bugs and bug fixes, and provide training. They also help those in needthrough the community’s forums such as mailing lists and IRC channels. Anyonecan join the developer community and the community is always willing to helpits members and the User Community to get the most out of the Zephyr Project.

Welcome to the Zephyr community!

Resources¶

Download Zephyr Port Devices Driver Windows 7

Here’s a quick summary of resources to find your way around the Zephyr Projectsupport systems:

• Zephyr Project Website: The https://zephyrproject.org website is thecentral source of information about the Zephyr Project. On this site, you’llfind background and current information about the project as well as all therelevant links to project material.

• Releases: Source code for Zephyr kernel releases are available athttps://zephyrproject.org/developers/#downloads. On this page,you’ll find release information, and links to download or clone sourcecode from our GitHub repository. You’ll also find links for the ZephyrSDK, a moderated collection of tools and libraries used to develop yourapplications.

• Source Code in GitHub: Zephyr Project source code is maintained on apublic GitHub repository at https://github.com/zephyrproject-rtos/zephyr.You’ll find information about getting access to the repository and how tocontribute to the project in this Contribution Guide document.

• Samples Code: In addition to the kernel source code, there are alsomany documented Sample and Demo Code Examples that can help show youhow to use Zephyr services and subsystems.

• Documentation: Extensive Project technical documentation is developedalong with the Zephyr kernel itself, and can be found athttp://docs.zephyrproject.org. Additional documentation is maintained inthe Zephyr GitHub wiki.

• Cross-reference: Source code cross-reference for the Zephyrkernel and samples code is available athttps://elixir.bootlin.com/zephyr/latest/source.

• Issue Reporting and Tracking: Requirements and Issue tracking is done inthe Github issues system: https://github.com/zephyrproject-rtos/zephyr/issues.You can browse through the reported issues and submit issues of your own.

• Security-related Issue Reporting and Tracking: For security-relatedinquiries or reporting suspected security-related bugs in the Zephyr OS,please send email to vulnerabilities@zephyrproject.org. We will assess andfix flaws according to our security policy outlined in the Zephyr ProjectSecurity Overview.

  Security related issue tracking is done in JIRA. The location of this JIRAis https://zephyrprojectsec.atlassian.net.

• Mailing List: The Zephyr Development mailing list is perhaps the most convenientway to track developer discussions and to ask your own support questions tothe Zephyr project community. There are also specific Zephyr mailing listsubgroups for announcements, builds, marketing, and TechnicalSteering Committee notes, for example.You can read through the message archives to followpast posts and discussions, a good thing to do to discover more about theZephyr project.

• IRC Chatting: You can chat online with the Zephyr project developercommunity and other users in our IRC channel #zephyrproject on thefreenode.net IRC server. You can use the http://webchat.freenode.net webclient or use a client-side application such as pidgin.

Download Zephyr Port Devices Driver Manual

Fundamental Terms and Concepts¶

Download Zephyr Port Devices Driver Installer

See Glossary of Terms