GSoC 2022: The first phase of completed projects

Google Summer of Code (GSoC) is a global, online program focused on bringing new contributors into open source software development. GSoC contributors work with an open source organization on a 12+ week programming project under the guidance of mentors. The updates to the program beginning in 2022 included a rolling timeline, which allowed considerable flexibility for contributors to either finish their projects in 12 weeks or extend their deadline up to 22 weeks. We are happy to announce that 755 contributors from 51 countries have successfully completed this year’s program thus far. Congratulations!

No GSoC is complete without our dedicated mentors and organization administrators from all around the globe. In its 18th year of the program, GSoC continues to thrive due to its robust mentor community. There are 198 open source organizations—and over 2,000 mentors from 76 countries—that are participating in the 2022 program. A sincere thank you to our mentors and organization administrators for guiding and supporting our contributors this year.

Throughout the course of the program, evaluations provide us a window to the GSoC experience that only a contributor or a mentor have. Evaluations have also influenced a number of GSoC program changes and events. At the suggestion of last year’s contributors, we held this year’s Contributor Summit earlier with several talks on how to have a successful Google Summer of Code. Mentor and contributor comments helped validate the changes to both projects and contributors that expanded the reach and flexibility of GSoC in 2022. We also held feedback sessions with our mentors to talk through their questions, suggestions and opinions on the changes we implemented this year. Our contributors and mentors inspire GSoC administrators too, and for that, we are truly grateful.

We’ll be back in a couple of months to give a final update on the GSoC projects that will conclude in October and November. Google Summer of Code 2022 hasn’t fully ended just yet, so please stay tuned!

By Romina Vicente – Google Open Source Programs Office

Co-simulating ML with Springbok using Renode

The landscape of Machine Learning software libraries and models is evolving rapidly, and to satisfy the ever-increasing demand for memory and compute while managing latency, power and security considerations, hardware must be developed in an iterative process alongside the workloads it is meant to run.

With its open architecture, custom instructions support and flexible vector extensions, the RISC-V ISA offers an unprecedented capacity for such co-design. And by energizing the open hardware ecosystem, RISC-V has supercharged research and innovation into how to improve chipmaking itself to better leverage the methods and suit the needs of software. Initiatives such as Google’s OpenMPW Shuttle show how a more open and software-focused approach to building hardware, are key to enabling a new wave of more powerful and transparent ML-focused solutions.

A RISC-V-based ML accelerator with a HW/SW co-design flow

In the past months, Google Research has joined efforts with Antmicro to work on a silicon project that can serve as a template for efficient hardware-software co-design. For their secure ML solution, the Google Research team supported by Antmicro has been developing a completely open source, rapid pre-silicon ML development flow using Renode, Antmicro’s open source simulation framework.

This builds on the result of cooperation from last year in which Antmicro implemented Renode support for RISC-V Vector extensions, which are used in the Google team’s RISC-V based ML accelerator codenamed Springbok. To allow a more well-rounded developer experience, as part of the project Antmicro is also working on improving the support for the underlying SoC and a large number of user oriented features such as OS-aware debugging, performance optimizations, payload profiling and performance measurement capabilities.

Springbok is part of Google’s AmbiML project that aims to create an open source ML development ecosystem centered on privacy and security. By using the RISC-V Vector extensions, the Google Research team has a standard but flexible way to parallelize the matrix multiply and accumulate operations that are universal in ML payloads. And thanks to Renode, the team can make informed choices as to how exactly to leverage RISC-V’s flexibility by analyzing tradeoffs between speed, complexity and specialization in a practical, iterative fashion using data generated by Renode and the text-based configuration capabilities that let them play around with hardware composition and functionality in a matter of minutes, not days.

On the ML software side, the ecosystem revolves around IREE—Google’s research project developing an open source ML compiler and runtime for constrained devices, based on LLVM MLIR.

IREE allows you to load models from typical ML frameworks such as TensorFlow or TensorFlow Lite and then convert them to Intermediate Representation (MLIR), which later goes through optimizations on graph level and then through an LLVM compilation flow to get the best-fitted runtime for a specific target. When it comes to deploying models on target devices, IREE provides APIs for both the C and Python programming languages as well as a TFLite C API which provides the same convention as TFLite for model loading, tensor management and inference invoking.

Using these runtimes, the model can be deployed and tested, debugged, benchmarked and executed on the target device or in a simulation environment like Renode.

Demoing the flow at Spring 2022 RISC-V Week

In the build up to the Spring 2022 RISC-V Week in Paris, the first such large open hardware meeting in years, an initial version of the AmbiML bare metal ML flow was released as open source. This includes both the ability to run interactively and an example CI using Antmicro’s GitHub Renode Action showing how such a workflow can be tested automatically on each commit. As a Google Cloud partner, Antmicro is currently working with Google Cloud to make Renode available for massive scale CI testing and deployments for scenarios similar to this one.

In a joint talk at the Paris event, Antmicro and Google presented the software co-development flow, together with a demo of a heterogeneous multi-core solution, with one core running the AmbiML Springbok payload and another core running Zephyr.

In the presented scenario the Springbok core, acting as a ML compute offload unit to the main CPU, executed inference on the MobileNetv1 network and reported the work done to the application core via a RISC-V custom instruction. Adding and modifying custom instructions is trivial in Renode, either via a single line of Python, C#, or even co-simulated in RTL.

Renode helps ML developers and silicon designers not only to run and test their solutions, but also to learn more about what their software is actually doing. As part of the Paris demonstration, Antmicro and Google showed how you can count executed instructions and how often specific opcodes are used to measure how well your solution is performing. These features, accompanied by execution metrics analysis, executed functions logging, and recently developed execution trace generation, give you great insight into every detail of your emulated ML environment.

These capabilities join the wide arsenal of hardware/software co-development solutions in Renode, such as RTL co-simulation which Antmicro has been developing with Microchip and support for verilated custom instructions developed with another ML-focused Google team responsible for RISC-V Custom Function Units and also used in the EU-funded VEDLIoT project.

Future plans

This is just the beginning of a wider activity from the Google Research team Antmicro is working with to release software and hardware components as well as tools supporting a collaborative co-design ecosystem for secure ML development. If you think Renode, RISC-V and co-development could help in building your next ML-focused product, go ahead and try the AmbiML flow yourself!

Visit the iree-rv32-springbok repository on GitHub, clone it locally and follow the instructions from README.md.

You can also grab Renode from the official repository and start playing with the available demos, or head to the Renode documentation to read up on features helpful for ML acceleration development such as Verilator co-simulation.

By Peter Zierhoffer – Antmicro

Google and NIST partner on nanotechnology development platform

We’re proud to announce Google’s cooperative research and development agreement with the U.S. National Institute of Standards and Technology (NIST) to develop an open source testbed for nanotechnology research and development for American universities. NIST—a bureau of the U.S. Department of Commerce—will start by migrating their existing planarized wafer designs to an open source framework, which can be manufactured in the U.S. on SkyWater Technologies’ open source 130nm process (SKY130). The physical wafers and source code will be available in the coming months. Together, NIST, Google, and the open source community will develop designs to facilitate research into both basic and applied science, including technology transfer into production with U.S. manufacturers.

Furthering Google’s goals to improve access to semiconductor technology, this agreement will provide academic researchers with unprecedented resources from a semiconductor foundry to enhance research into the physics of semiconductors and nanodevices. This includes their chemistry, defects, electrical properties, high frequency operation, and switching behavior, while reducing overall costs through economies of scale. Most importantly, this access enhances the technology transfer process by enabling researchers to develop new and emerging technologies using foundry resources, that can then be seamlessly transitioned into mass production since universities will already be using an industrially relevant platform. This will greatly improve scientist’s ability to move their technologies through the tech-transfer “valley of death” and into practical use.

Nanotechnology research has benefitted from silicon wafers that are normally used for chip manufacturing in a unique way. Instead of turning them into packaged microchips, their smooth, planarized surface makes a great substrate for building and testing nanoscale structures. This likewise helps test their transition into mass production.

Picture of a full wafer using the SKY130 open source PDK.

The wafer for this platform has a number of different metrology structures, from parametric test structures based on simple transistor arrays—which can be probed in a probe station—to thousands of complex measurements that users can operate using synthesized digital circuits. Critically, the wafers will be available to universities in a 200 mm form factor, and mid-production planarized wafers with less than a single nanometer of surface roughness. Smooth, flat surfaces are critical for advanced manufacturing at small sizes.

NIST researchers are also ensuring that the wafers have photolithographic and electron beam alignment marks commonly found in university nanofabrication facilities, allowing the foundry silicon to be used directly by university researchers with ease. Metal pads on the surface will allow scientists to access the semiconductor transistors from the surface.

NIST scientists anticipate the nanotechnology accelerator platform will enhance scientific investigations into a diverse set of technologies, including memory devices (resistive switches, magnetic tunnel junctions, flash memories), artificial intelligence, plasmonics, semiconductor bioelectronics, thin film transistors and even quantum information science.

Picture of a development die from Google 's OpenMPW program for the nanotechnology accelerator developed by NIST and the University of Michigan

This program also benefits from Google’s previous contributions and support of the GDSFactory and OpenFASOC open source projects that help automate and shorten the construction of these important measuring devices from months to days. Ahead of the full wafer tapeout in 2023, NIST scientists, working with partners at the University of Michigan, Carnegie Mellon, University of Maryland, The George Washington University, and Brown University have been using Google's OpenMPW program to develop and test preliminary circuits which they expect to include in the nanotechnology accelerator. Preliminary testing will help ensure the program’s goals are met with working circuits that best serve the scientific community.

A key factor in cutting-edge research is reproducibility, or the ability for researchers from different institutions to repeat each other’s experiments and improve upon them. By migrating to an open source framework, researchers can more easily share reproducible results, contribute to the creation of open source datasets to enhance future simulation, and advance the scientific community’s state of the art of nanotechnology and semiconductor manufacturing.

NIST and Google will distribute the first production run of wafers to leading U.S. universities. Post-program, American scientists will be able to directly purchase the wafers from Skywater without license requirements, giving them the freedom to pursue their research without any restrictions. Since wafers are hundreds of times cheaper than full mask-sets or the cost of designing integrated circuits from scratch, scientists will have a much easier time getting and using this powerful industrial technology. Longer term, working with NIST to develop future platforms on the recently announced SKY90FD open source PDK will further expand this R&D ecosystem.

To kick off this research effort NIST is organizing the "NIST Integrated Circuits for Metrology Workshop" from September 20–21, 2022. This workshop will be held online with a series of presentations and panel discussions on the first day. During the second day, a working group of researchers, scientists and engineers will work to focus on the creation of parametric test structures for monolithic integration using open source silicon technology. Visit the event website to get more details about this program and register to attend or learn more about presenting.

By Ethan Mahintorabi and Johan Euphrosine, Software Engineers – Hardware Toolchains Team, and Aaron Cunningham, Technical Program Manager – Google Open Source Programs Office