Google Summer of Code 2017 - Ideas for Projects

We are happy to announce that we have been selected to participate in Google Summer of Code 2017!

Whether you’re an aspiring student or mentor, feel free to contact us, either through the private GSoC-specific mailing list, through the public discussion mailing list, or through the mentors listed for each project below. We are also available at #librecores on freenode if you’re an IRC user.

Looking forward to meet you all!

Ideas Overview

Details: Our main goal is to grow the community around open source silicon designs. LibreCores are IP cores, but they are free and open. While there are many projects you can contribute too, you may have your own great idea for a LibreCore. All projects start small, and we see this is a great chance to bring forward new ideas and start building new tiny bits and pieces that enable free and open source chips.

We are happy to mentor you with your own idea, but it is important that it is re-usable and contains everything needed for simple and flexible integration, like testbenches, the required software drivers etc. So, it is important that you discuss a proposal intensively.

Skill level: All

Language/Tool: Verilog, VHDL, Chisel, …

Mentor: We will find the mentor with you, LibreCores GSoC team

GPIO Switchbox

Details: FPGA boards are equipped with manyfold IO interfaces. Most of those IO interfaces are general purpose IO (GPIO) that are connected to standardized headers. One example are PMOD connectors or the Arduino shield connector.

If you build a system-on-chip nowadays the IO functions, such as GPIO, UART or SPI, are hard-wired to pins on those headers. Connecting for example other PMODs required re-synthesizing the design. I have started PMOD switchbox to allow the programmer to dynamically configure the IO functions at runtime. The goal is to generalize this approach and build an interesting prototype.

Skill level: Beginner, Intermediate

Language/Tool: Verilog

Mentor: Stefan Wallentowitz

First-Generation Museum on FPGA

Details: The first computers were cabinet sized, vacuum tube-powered and their computational power was very limited compared to what we know today. Not only as fun projects, it is an interesting excercise to implement those masterpieces on a single chip today. It helps students and hobbyists to understand the inner working of computers and learn about programming principles.

The goal of this project is to replicate one of those historic computers, such as the EDSAC, ENIAC, SSEM in a hardware description language and port them to an FPGA demonstrator.

Beside getting the basic understanding of the machine, an important task is to map the (ancient) I/O devices to a modern demonstrator setup.

Skill level: Beginner, Intermediate

Language/Tool: Verilog, VHDL, (Yosys) FPGA synthesis flow

Mentor: Andrew Back, Jeremy Bennett

FuseSoC Generators

Goal: Create a way to run external tools that generates files on-the-fly in a FuseSoC workflow

Details: When running a simulation or a synthesis flow it is often desirable to generate some files on-the-fly. This can be for generating RTL files from vendor-specific IP core descriptions, IP-XACT files or create an ELF file from C sources.

While FuseSoC already has support for calling external scripts at different parts of the toolflow, and many EDA tools have built in support for TCL scripting, it lacks a deeper integration into FuseSoC that is needed to efficiently perform some of these tasks.

The task includes both support for allowing cores to register themselves as generators as well as support for other cores to use them.

Examples of tasks that could make good use of generators

  • Xilinx CoreGen (replaces coregen provider)
  • Altera Qsys
  • Generate Wishbone interconnects (by running wb_intercon_gen in
  • Create verilog from Chisel/Migen/IP-Xact descriptions… etc

Skill level: Intermediate

Language/Tool: Python, basic knowledge of EDA tools

Mentor: Olof Kindgren

FuseSoC Provider for LibreCores API

Details: Currently, FuseSoC fetches the core description files from local copies of repositories. The goal of this project is to fetch the core descriptions from the LibreCores website instead.

In a first step, you must first coordinate with our LibreCores team to define the additional requirements for the API. Then FuseSoC should be extended to provide core files from other sources and then implement the (recursive) fetching of core files.

Skill Level: Intermediate

Language/Tool: Python

Mentors: Stefan Wallentowitz, Olof Kindgren

Open Source Allure Test Report Adapter for UVM

Goal: The goal of this project is to create an Allure Test Report Adapter that extends the UVM report server. Allure test reports can be consumed by automation tools such as Jenkins.

Details: The Universal Verification Methodology (UVM) is a standardized methodology for verifying integrated circuit designs. Integrated Circuit Verification is the most time consuming activity in hardware development. The UVM standard is used by several ASIC and FPGA teams to create complex verification environment that ensure designs are thoroughly verified in simulation before being released. A key aspect of verification is the ability to automatically process millions of test reports, but the native test reporting capabilities of UVM are limited and do not readily integrate with existing automation tools.

Skill level: Intermediate

Language/Tool: SystemVerilog, Simulator

Mentor: Martin d’Anjou

Constrained randomised testing with coverage tracking in Cocotb

Goal: Extend the Cocotb co-simulation library to support constrained randomised testing (e.g. via Google or-tools) and to track achieved coverage of the tested HDL.

Details: Cocotb is a Python framework for testing VHDL and [System]Verilog hardware designs. Although various open source simulators are available, none of them provide the advanced verification features of expensive proprietary simulators. This project will implement constrained randomisation and functional coverage collection in Cocotb, giving open source projects these capabilities.

Constrained Randomisation is a similar concept to fuzz testing; generating random stimulus transactions according to certain constraints in order to exercise a hardware design. To understand how well the randomly generated inputs are testing design the we also need to instrument the code to track metrics on which scenarios have been exercised (known as functional coverage).

The goal of this project is to provide a convenient interface to an existing constraint solver from Cocotb and create and manage a database of functional coverage points. To facilitate processing of the coverage data we’ll need to export to various formats for consumption by other tools. We can also integrate coverage information with existing software development services such as

By undertaking this project you will learn about latest ASIC/FPGA verification practices and the interaction between hardware and software development

Skill Level: Intermediate

Language/Tools: Python

Mentor: Chris Higgs

Open Source Mixed-Language HDL Simulation

Details: While there are good Free and Open Source VHDL and Verilog simulators, there is currently no project which allows the simulation of mixed-language HDL designs with a reasonable coverage of the VHDL and Verilog languages and with good performance. The project will consist in finding a good way to capitalize on existing efforts (GHDL, Icarus Verilog, Verilator, etc.) to come up with a solution and implementing a proof-of-concept system that allows the simulation of a simple mixed-language design.

Skill Level: Intermediate, Advanced

Language/Tool: C++, Flex/Bison, Understand the tool flow

Mentor: Tristan Gingold, Olof Kindgren

Open Source HDL Micro-Benchmark Suite

Details: The open source EDA tool ecosystem is growing significantly. For example digital synthesis and formal verification tools are reaching a state of professional performance. To compare such tools to each other and improve the results of the tools, standardized benchmark suites are commonly used, for example IWLS2005.

Such benchmarks are usually rather complex designs. The idea is hence to collect benchnmarks and to generate micro-benchmarks from basic functions automatically. Some example work has started here.

Skill Level: Intermediate

Language/Tool: Verilog, Python

Mentor: FOSSi GSoC team

Contributions to Yosys Ecosystem

YoSys is a framework for Verilog RTL synthesis. The following list is incomplete and is meant to inspire student proposals. Do not simply pick one of the projects on this list! We are interested in genuinely original student proposals. Please contact the FOSSi GSoC team early in the process to discuss your ideas.

Ideas regarding Project IceStorm (the FOSS iCE40 FPGA flow)

  • Improvements in Arachne-pnr place & route tool, such as
    • Analytical (e.g. quadratic wirelength) placement
    • Support for LUT cascade feature
    • Support for BRAM cascade feature
    • Improved inference of SB_IO cells
    • Timing driven place and route
    • Speedups (OpenCL?)
  • Alternative iCE40 place and route flow (e.g. using VPR/VTR)
  • Additional support for more iCE40 devices (e.g. UltraLite)
  • In-hardware validation flow for chip databases

Ideas regarding Yosys

  • Additional front- and back-ends
  • New architectures (e.g. additional FPGA families)
  • New non-synthesis flows (verification, etc.)
  • New yosys commands and other features

Ideas regarding YosysJS

  • Interactive schematic viewer running in the web browser
  • Puzzle games and other web-based Verilog training tools
  • Port of Icarus Verilog to JavaScript (using EMCC)

Skill Level: Intermediate/Advanced

Mentor: FOSSi GSoC team

Firrtlator Extensions

Details: firrtlator is a C++ library and tool to work on the Flexible Intermediate Representation for RTL (FIRRTL). The goal is to have a common library to interact with FIRRTL files, to integrate it with other tools, and to elaborate and optimize on the IR.

The project is at the beginning and I am open to all ideas around it. Here are some suggetions:

  • Integration with Verilator
  • Integration with the YoSys RTL-IR
  • Automatic injection of debug probes
  • Injection of logic to improve fault tolerance

Skill Level: Intermediate/Advanced

Mentor: Stefan Wallentowitz


LibreCores is a community web site with the goal of providing an overview of IP cores and the corresponding ecosystem, similar to the now abandoned site. For further information on our goals, see the FOSDEM Presentation slides announcing LibreCores. The full site source code is available on GitHub. The issues also contain some plans and tasks to be taken on.

Please talk to Philpp for a full description of available tasks and a discussion what can/should be done, also based on your existing experience.

Skill Level: Intermediate

Language/Tools: PHP with the Symfony Framework, MySQL, HTML/JS

Mentor: Philipp Wagner

Continuous Integration for Hardware Projects on LibreCores CI

Goal: Setup verification and continuous integration flow for one of open-source digital hardware projects.

Details: LibreCores CI is a under-development Continuous Integration service within LibreCores. In this project we offer students to work with modern hardware verification tools, RTL codebase and Jenkins Pipeline in order to setup efficient verification flows for one of the open-source hardware project being hosted on LibreCores. The project includes improvements of the HW project testability in RTL, development/improvement of testing frameworks and a development of a new Pipeline Library for automation in Jenkins.


  • Basic knowledge of the hardware verification techniques
  • Knowledge of one of RTL languages
  • Knowledge of one of the scripting languages (preferably Python or Groovy)

Skill Level: Intermediate

Language/Tools: Verilog/VHDL/…/Python, Jenkins, Groovy

Mentors: Oleg Nenashev, Stefan Wallentowitz

EDA Tool plugin for Jenkins and LibreCores CI

Goal: Create a new Jenkins plugin for an Electronic Design Automation (EDA). This plugin is expected to be integrated with Jenkins Pipeline

Details: In LibreCores we are working on setting up the Jenkins-based continuous integration system for open-source digital hardware projects (see LibreCores CI). We would be interested to improve the integration of Jenkins with EDA tools being widely used in open-source digital hardware projects. It could be either an open-source EDA tool (e.g. Icarus Verilog, Cocotb, Verilator) or a widely-used proprietary one with a free use option (e.g. Quartus Prime, ModelSim).


  • Basic knowledge of the hardware engineering area
  • Basic knowledge of Java programming language
  • In the case of FPGA flows it would be useful to have a prototyping board as well.

Skill Level: Intermediate

Language/Tool: Jenkins, one of EDA tools, Java

Mentors: Oleg Nenashev, Martin d’Anjou

OpenRISC or RISC-V Port of the ROMCC (ROM C Compiler)

ROMCC, created by Eric Biederman, generates machine code from C that uses only CPU registers—meaning machine code that needs no stack and, therefore, no initialized RAM. This compiler is used in the Coreboot project.

Skill Level: Beginner/Intermediate

Language/Tools: C, Assembly

Mentor: tbd, Stefan Wallentowitz


There is a GCC port for OpenRISC, but it lacks the potential to become a part of the official upstream GCC due to copyright assignments. We hence plan a clean room rewrite of the very basic infrastructure, based on other clean room implementations. You should have an understanding of compilers and be able to work in a very structured way.

Skill Level: Advanced

Language/Tools: C, Compilers

Mentor: Stafford Horne

Reference Implementation for a Leakage Aware Compiler Optimization

The Leakage Aware Design Automation Project (LADA) is led by Dr Elisabeth Oswald at Bristol University and funded over four years by the UK EPSRC.

Embecosm is industrial partner to this project, charged with applying the research to the next generations of free and open source compilers, such as GCC and LLVM. Many of these innovations involve hardware changes that the compiler can leverage (e.g. checksumming code on the fly).

In this project you will work to add appropriate hardware functionality to your favorite open hardware processor design (AAP, OpenRISC, RISC-V etc), and then extend either GCC or LLVM to support that hardware functionality. You will need both Verilog and Compiler skills, as well as some grasp of side-channel attacks in cryptography.

Skill Level: Advanced

Language/Tools: Verilog, C/C++

Mentors: Jeremy Bennett, Simon Cook

GNU Superoptimizer 2.0: Reference Implementation for the AAP

James Pallister presented the design and initial implementation for GSO 2.0 and GNU Tools Cauldron in 2015: Youtube

In this GSoC project you will implement GSO 2.0 for the AAP instruction set and demonstrate its effectiveness over code generate using LLVM for AAP. An advanced student would implement stochastic superoptimization to allow longer code sequences to be tackled.

Skill Level: Intermediate/Advanced

Language/Tools: C/C++. AAP assembler

Mentors: Jeremy Bennett, Ed Jones

An Altruistic Processor (AAP): Reference Implementation

AAP is the compiler writer’s architecture from hell. It was created to advance compiler support for common deeply embedded architectures, and includes many features that cause great difficulty when compiling.

In order to be credible, we must show that AAP can be implemented on real silicon. A student implementation was created by Dan Gorringe in 2015 and presented at ORConf 2015 at CERN: Youtube

This GSOC project is to provide a full implementation, complete with debug interface to run on an appropriate small FPGA board such as a DE0-Nano.

Skill Level: Advanced

Language/Tools: Verilog, Yosys FPGA synthesis tool flow

Mentors: Jeremy Bennett, Simon Cook, Andrew Burgess

A SystemVerilog Preprocessor

The SystemVerilog hardware description language has an extensive set of preprocessor features, and antlr has established itself as one of the best tools for building lexers and parsers. However it is not possible to parse SystemVerilog with antlr (or any other toolkit) unless the preprocessor directives have been processed. The preprocessor directives include among other things, parameterized macros, token pasting, conditionals, includes, etc. The goal of this project is to write this preprocessor. This will enable the creation, in the future, of antlr based SystemVerilog tools (code analyzers, compilers, simulators, synthesizers, etc).

Skill Level: Advanced

Language/Tools: Antlr, Java or C++, SystemVerilog

Mentors: Martin d’Anjou

Open SoC Debug: Nexus Trace Format

Trace debugging is the method to observe the execution of a system-on-chip. The Open SoC Debug project creates open source building blocks for a debug infrastructure, with a strong focus on efficient trace debugging.

One of the main challenges is the transfer of trace events to the host. On the one for efficiency and on the other hand for compatibility.

The goal of this project is to adopt the Open SoC Debug infrastructure to packatize traces in the popular Nexus (IEEE 5001) format.

Skill Level: Intermediate

Language/Tools: SystemVerilog

Mentor: Stefan Wallentowitz

Open SoC Debug: Trace Visualization and Configuration

Details: The Open SoC Debug project creates open source building blocks for a debug infrastructure, with a strong focus on efficient trace debugging. Currently we focus on the target (hardware) side of the infrastructure, but want to improve the host software, especially visualization of traces and configuration of the debug hardware.

In this project you should not reinvent the wheel, but build around existing infrastructure. For example the Open Trace Format 2 and the SCORE-P infrastructure are good starting points. For the visualization and interface building we suggest having a look at state of the visualization tools like ravel to integrate with or build a new framework for example on electron.

Skill level: Beginner, Intermediate

Language/Tools: C++/Java/JS

Mentor: Philipp Wagner, Stefan Wallentowitz

Open SoC Debug: Trace Logging to Memory

Details: In the Open SoC Debug we currently transfer traces from the debug target to the host for on-line visualization or offline processing. But low level traces may be interesting even while the system-on-chip is in the field, similar to system traces, e.g. from Linux. The idea is to write the traces to a reserved space in the system memory and read them from the running software.

Basically this idea involves two hardware tasks: A configuration interface for trace logging and the interface between the debug interconnect and the system memory. Ideally your proof-of-concept includes a simple software. This setup can be optimized for example with trace compression and circular buffering.

Skill level: Intermediate

Language/Tools: System Verilog

Mentor: Stefan Wallentowitz

LimeSDR: Integrate RISC-V Core

Details: LimeSDR is a flexible software-defined platform, that integrates an FPGA and a Lime Microsystems LMS7002M field-programmable RF transceiver, that is 2x2 MIMO and can be tuned anywhere from 100KHz to 3.8GHz. The FPGA is presently used to take care of things such as interfacing, digital down-conversion and tuning, and sample time-stamping.

Currently the Altera NIOS-II processor is used and in this project the goal is to replace it with an open source softcore implementing the RISC-V instruction set.

It consists of three parts:

  • Identify a suitable RISC-V processor core
  • Integrate the RISC-V processor core
  • Proof-of-concept of the updated software environment

Skill level: Intermediate

Language/Tools: HDL, FPGA synthesis

Mentor: Andrew Back

LimeSDR: Switch to a FuseSoC-based Development Flow

Details: The LimeSDR-USB platform integrates an FPGA that contains a System-on-Chip and DSP. The System-on-Chip employs a softcore for interfacing with the programming interface of RF transceiver, while hardware blocks take care of streaming, DSP and sample time-stamping.

With the integration of more and more blocks and a varying number of FPGA implementations for different users, a structured way of managing the dependencies and composition of hardware blocks is needed. For that we would like to provide a FuseSoC-based environment.

The goal of this project is to structure the repositories and add the infrastructure files for FuseSoC, along with a proof-of-concept demonstration and a tutorial.

Skill level: Beginner, Intermediate

Language/Tools: Understanding of HDL Synthesis

Mentor: Andrew Back

OpTiMSoC: Linux Port

Details: The Open Tiled Manycore System-on-Chip is a prototyping platform for massively parallel multicore system-on-chip. The main runtime environments we employ so far are baremetal and a very lean operating system (“compute node OS”).

In this project the student should evaluate the minimal set of Linux to compile for such platforms and customize the OpenRISC Linux port accordingly. Beyond that the goal is to integrate the device driver for the communication infrastructure. Finally, we want to explore different use cases of Linux and if time permits the student should explore different communication patterns.

Skill level: Intermediate, Advanced

Language/Tools: C, FPGA synthesis flow

Mentors: Stefan Wallentowitz, Philipp Wagner

SystemC generator plugin for Kactus2

The project objective is to implement a SystemC generator for Kactus2, an open-source IP-XACT tool. IP-XACT captures designs and components independent of implementation language, but the ability to generate SystemC from IP-XACT would enable designers to leverage SystemC for simulation and verification of their IP.

Skill level: Intermediate

Language/Tools: C++/Qt, SystemC

Mentor: Esko Pekkarinen

3D browser for IP-XACT library for Kactus2

Browsing lists and tree structures in a graphical user interface is often tedious and relations between the objects may not be intuitive. Recently 3D visualization has become a rich alternative to traditional navigation. The project objective is to implement 3D browsing for IP-XACT objects in Kactus2 tool.

Skill level: Advanced

Language/Tools: 3D graphics, C++/Qt, User interface design

Mentor: Esko Pekkarinen

RISC-V DSP library on the Pulpino platform

Pulpino is an open-source design containing a 32-bit RISC-V implementation enhanced with DSP extensions. Pulpino is part of the PULP project, an ecosystem of open-source hardware and software targeting a new generation of parallel ultra-low-power IoT devices.

The goal of this project is to develop a RISC-V DSP library for the Pulpino platform. The implementation will consist in selecting a reasonable set of common signal processing functions, implementing it on Pulpino, optimizing it to take advantage of the RISC-V DSP extensions, and finally benchmarking it. This will help measuring the impact of the existing extensions and drive future extensions. Work could also be extended to the parallelization of this subset on the Pulp platform.

Skill level: Intermediate

Language/Tools: C/C++

Mentor: Davide Rossi

Adding support for Pulpino platform on ARM mbed IoT Device Platform

Pulpino is an open-source design containing a 32-bit RISC-V implementation enhanced with DSP extensions. Pulpino is part of the PULP project, an ecosystem of open-source hardware and software targeting a new generation of parallel ultra-low-power IoT devices. The ARM mbed IoT Device Platform provides the OS, cloud services, tools and developer ecosystem to make the creation and deployment of IoT solutions fast and portable. The goal of this project is to extend the ARM mbed IoT Device Platform components to target the Pulpino platform. During the project the ARM mbed OS should be adapted to support the new target, and a proper support at IDE level should be developed.


Skill level: Advanced

Language/Tools: C/C++, Python

Mentor: Davide Rossi

Recent activity

14 Mar 2023 » El Correo Libre Issue 60
Apply Now for Google Summer of Code 2023 We have once again been selected as a mentor organisation for Google..... more

07 Mar 2023 » Apply Now For GSoC 2023!
We have once again been selected as a mentor organisation for Google Summer of Code (GSoC) 2023. Google Summer of..... more

14 Feb 2023 » El Correo Libre Issue 59
First Speakers Confirmed for Latch-Up 2023 in Sunny Santa Barbara The FOSSi Foundation is proud to announce the first batch..... more

10 Jan 2023 » El Correo Libre Issue 58
Preparations Begin for Latch-Up 2023 The FOSSi Foundation is very pleased to announce that Latch-Up will go ahead in 2023!..... more

01 Jan 2023 » Latch-Up and ORConf return in 2023
We announced in ECL 57 our North American open source silicon conference “Latch-Up” will return in 2023. And it will..... more

The Free and Open Source Silicon Foundation C.i.C.
Unit C5, Tenterfields Business Park, Halifax, England, HX2 6EQ