El Correo Libre Issue 26

Published in

LibreCores

11 min readApr 14, 2020

Google Summer of Code 2020

Since 2016 the FOSSi Foundation has participated every year in the Google Summer of Code, a Google-sponsored summer internship for students from all over the world. We are honoured to be part of GSoC again this year. As in previous years, the FOSSi Foundation acts as an umbrella organization, supporting community members to mentor students in their respective FOSSi-related projects.

Today, the student applications closed, and we’ll hopefully soon be able to announce a list of students who will be working with their mentors and us during the summer.

Over the years, we’ve learned a lot how to best support our students and mentors. The essentials of that are now summarized in the FOSSi Foundation GSoC house rules, available on our web site. We invite all our students and mentors to have a look at this document, and get back to us if there are open questions or ideas for improvement.

We are looking forward to many exciting projects this summer (or winter for our friends down under)!

-Philipp Wagner, Director, FOSSi Foundation

Cocotb Opens User Survey 2020

Users of the Python verification testbed platform cocotb — the COroutine-based COsimulation Test Bench — are invited to participate in the project’s ten-minute annual user survey, aiming to steer development for the coming year.

“Cocotb is free to download, it doesn’t contain any telemetry, and doesn’t require a registration before downloading. That’s great for the cocotb users — as long as the current feature set is exactly what is required,” explains FOSSi Foundation director Philipp Wagner. “At the same time, this situation makes it hard for the cocotb development community to steer development efforts into the right direction. Which operating systems are used most? Which feature is loved most? Which bug is most annoying?

“If you’re using cocotb, your answers to these questions are extremely important. Please take a couple minutes to answer the questions in this year’s cocotb user survey, to make sure your use of cocotb gets the attention it deserves! Thank you!”

The survey is available now on Google Docs; questions relating to the survey should be directed to either the cocotb maintainers’ mailing list or directly to Philipp via email.

CERN Publishes Open Hardware Licence 2.0, Covers Software Too

CERN, the European Organisation for Nuclear Research, has officially launched the second iteration of its popular licence for open hardware —an update in which the FOSSi Foundation was involved.

“The CERN-OHL is to hardware what the free and open-source licences are to software,” claims Myriam Ayass, legal adviser for the CERN Knowledge Transfer Group, of the licence’s latest release. “It defines the conditions under which a licensee will be able to use or modify the licensed material. It shares the same principles as free software or open-source software: anyone should be able to see the source — the design documentation in the case of hardware — study it, modify it and share it.”

“Open hardware gives designers and users the freedom to share hardware designs, modify them, manufacture products based on the design files and commercialise those products,” adds Open Hardware Repository founder Javier Serrano. “This freedom enables collaboration among engineers, scientists, researchers, hobbyists and companies without the risk of vendor lock-in or other issues present in proprietary development.”

The new version of the licence comes in three variants: One is fully permissive, while the other two are strongly and weakly reciprocal — i.e. require derivatives and modifications to be published under the same licence as the original project.

The CERN-OHL 2.0 is available on the CERN website now.

OpenPOWER Announces Power Vector Intrinsics Reference Review

The OpenPOWER Foundation has announced public review of its Power Vector Intrinsics Programming Reference, a documented designed to assist developers in making use of the Power instruction set architecture’s vector instructions.

“The new PVIPR document provides developers with resources for effectively programming Power Instruction Set Architecture’s vector instructions,” explains IBM’s Bill Schmidt of the publication. “This document provides background on the vector architecture and the application binary interface (ABI), describes Power’s unique bi-endian vector programming model, discusses best practices for vector programming, and contains a complete reference for each vector intrinsic function available for Power ISA 2.7 and 3.0.

“This information is also useful for compiler developers who want to be compliant with existing compilers for Power. To this end, PVIPR provides sample implementations of each vector intrinsic function.

“Historically,” Bill notes, “some of this information is also available in the 64b ELFv2 ABI Specification. Since the vector intrinsics are not truly part of the ABI, we moved the information into a new, expanded document, and improved its utility as a quality reference document. Future versions of the ELFv2 ABI specification will remove the now-redundant information and point to this document instead.”

The draft is available now on the OpenPOWER Foundation website; comments are open until the 15th of May 2020, and should be directed to the programming guide mailing list.

QEMU Emulator Prepares for 5.0.0 Release

The QEMU project is preparing to release version 5.0.0, with a second release candidate (RC) available at the time of writing, bringing in a wealth of improvements for free and open source silicon developers.

QEMU 5.0.0, which is now feature-locked and running through final tests prior to release, includes several bug fixes and enhancements of interest to the free and open source silicon community. Those working on the Power ISA will find initial support for POWER10 in the powernv machine type, new forms of the POWER9 slbia instruction, support for non-volatile DIMMs (NVDIMMs) with file backends, improved host resource consumption, and better error message reporting.

RISC-V users will find syscon device tree nodes for the virt and sifive_u boards, allowing generic syscon drivers within Linux to control power and reboot, along with a Goldfish real-time clock (RTC) in the virt board only. Experimental support has also been added for the draft 0.5 release of the hypervisor extension.

Some changes may not be welcomed, however: A particular loss is the removal of all Bluetooth code from QEMU, which its maintainers say “was quite neglected over the years.” Instead, Bluetooth is being pushed to external hardware via pass-through to a USB dongle.

A full list of changes for QEMU 5.0.0 can be found on the project wiki, while the release candidate is available for download now.

Antmicro Releases Renode 1.9

Antmicro has announced the release of Renode 1.9, the latest version of its popular open-source hardware/software co-development platform.

Renode 1.9 brings the platform’s first support for the RISC-V Privileged Architectrue v1.11, support for the RISC-V-based Kendryte K210 system-on-chip platform, the NeTV2 with LiteX and VexRiscv, a new LiteX system-on-chip controller model, support for use of the Wishbone bus in verilated peripherals, and the ability to create Conda packages across Linux, Windows, and macOS systems.

The new release also includes supervisor-level interrupts for VexRiscv, a sample binary for running FreeRTOS with the LwIP stack on a PolarFire FPGA, the exposure of additional RISC-V registers to the monitor system, parallel unit testing, and fixes for a range of bugs from improper window positioning to crashes when copying data to the clipboard on Windows.

The latest release is available to download now from the project’s GitHub repository, alongside the MIT-licensed source code.

Linux 5.6 Brings New Features for RISC-V

Version 5.6 of the open-source Linux kernel has been released, bringing with it new fixes and features for those running Linux on RISC-V systems.

According to a list of changes compiled by CNX Software, Linux 5.6 adds support for the Kernel Address Sanitiser (KASAN) protection system on RISC-V, along with 32-bit physical address support for rv32i-based cores. The new release also includes support for the Sifive Freedom U540 (FU540) RISC-V system-on-chip’s general-purpose input/output (GPIO) controller, along with DTS updates for the HiFive Unleashed development board.

Project maintainer Linus Torvalds, meanwhile, seems confident that development of Linux 5.7 is on track despite current global conditions. “While I haven’t really seen any real sign of kernel development being impacted by all the coronavirus activity — I suspect a lot of us work from home even normally, and my daughter laughed at me and called me a ‘social distancing champ’ the other day,” Linux joked in the release message, “it may be worth just mentioning: I think we’re all reading the news and slightly distracted.

“I’m currently going by the assumption that we’ll have a fairly normal 5.7 release, and there doesn’t seem to be any signs saying otherwise, but hey, people may have better-than-usual reasons for missing the merge window.”

The latest release is, as always, available to download from Kernel.org.

Dan Gisselquist Publishes Guide to Cheap Spectral Estimation in DSP Development

Gisselquist Technology’s Dan Gisselquist has published a walk-through to using the Wiener-Khinchin theorem for resource-light spectral estimation in digital signal processing (DSP) projects.

“What if you want to estimate the spectral content of a signal within your FPGA on a platform that doesn’t have the resources to accomplish a full FFT? What if I told you that you could get (roughly) the same spectrum estimate for only the cost of a single DSP element,” Dan writes, “about two FFT’s worth of block RAM and some LUTs to control the whole logic? Well, that and a nearby CPU? How about if I do one better, and say that the algorithm is easier to debug than an FFT?

“The key trick to this whole exchange is the Wiener-Khinchin theorem. The Wiener-Khinchin theorem states that the Fourier transform of the autocorrelation of a signal is equivalent to the Fourier transform of the Power Spectral Density of the same signal. Using this principle, we can estimate the autocorrelation of a signal and then later take an FFT of the autocorrelation to get our Power Spectral Density estimate.”

Dan’s full guide is available on the Gisselquist Technology website.

Linux Foundation to Host SeL4 Foundation

The Linux Foundation has announced the launch and its hosting of the seL4 Foundation, designed to promote development and uptake of the security-focused real-time operating system (RTOS) microkernel.

“The Linux Foundation will support the seL4 Foundation and community by providing expertise and services to increase community engagement, contributors and adopters, helping to take the OS ecosystem to the next level,” claims Michael Dolan, VP of strategic programs at the Linux Foundation. “The open governance and standards-based model will provide a neutral, mature and trustworthy framework to help advance an operating system that is readily deployable and optimized for security.”

“We are very excited about this step to provide a sustainable, long-term trajectory for seL4, and very keen to see the seL4 Foundation grow and thrive under the Linux Foundation umbrella,” adds Dr. June Andronick, Leader of Trustworthy Systems at the Data61 arm of Australia’s national science agency CSIRO.

“With the help of the Linux Foundation we can broaden the community of contributors as well as adopters of seL4,” concludes UNSW Scientia Professor Gernot Heiser, who is to chair the seL4 Foundation. “This will provide the support that allows us to continue the research that ensures seL4 will remain the most advanced and secure OS technology.”

More information on the Foundation is available on the seL4 website.

The European Union Launches Open-Hardware MEEP Project

The European Union’s MareNostrum Experimental Exascale Platform (MEEP) project has officially launched, with the Bacelona Supercomputing Centre (BSC) taking the role of coordinator.

“The MareNostrum Experimental Exascale Platform (MEEP), as a performance evaluation and software development vehicle for future chip designs, will provide European technology that will set a foundation for many systems, both in HPC and beyond,” claims John Davis, MEEP coordinator at BSC, of the project which officially launched this year. “By championing the open-source RISC-V instruction set architecture, MEEP will help ensure European technological sovereignty by avoiding the export restrictions associated with proprietary models, while building the software ecosystem necessary to make RISC-V viable for a wider range of applications.”

“By experimenting with RISC-V-based hardware designs through FPGA emulation, we can fine-tune the right architectures before committing to silicon,” adds Peter Hsu, MEEP director at BSC, of the organisation’s approach. “The emulation platform will also allow us to test the full stack, from applications to hardware.”

MEEP is to run for three years on a €10.3 million budget, with BSC being joined by experts from Croatia’s UNIZG-FER and Turkey’s TÜBİTAK BILGEM. More information is available on the project website.