lowRISC project ideas for GSoC 2020
Before submitting your application, please get in contact with us on our Zulip group chat or send an email to potential mentors. We are keen to start discussing potential projects with you.
For guidance on how to write the application, please check out the GSoC student guide.
Project ideas (in no particular order)
Your project here
If you have a project idea relevant to lowRISC, don’t worry that it’s not listed here. For a good student with an interesting project we’ll almost definitely have an appropriate mentor. You are strongly recommended to get in touch to discuss the idea though. Some projects might be better handled under a different mentoring organisation, e.g. a PyPy port to RISC-V would make more sense under the Python Software Foundation.
A template project for Ibex custom instruction set extensions
Summary: Create a starting point for Ibex implementers who wish to add custom instruction set extensions.
One part of this project is to demonstrate a methodology for doing this, which may involve making suggestions for refactorings to make this an easier task. The project would ideally involve addressing the challenge of keeping the example/template project functional.
Custom compressed instruction set generation
Summary: Create a flow that can generate a custom compressed instruction set tuned for a given firmware image.
This project would involve creating a tool that would analyse a firmware image, and generate a custom compressed instruction set (or alternatively, additions to the standard compressed instruction set) that would minimise code size. The tool would generate the necessary instruction descriptions for LLVM as well as the decode logic for the Ibex CPU core. There is a wealth of additional research ideas on further reducing code size that may also be interesting to explore in the context of this project.
OpenTitan SoC tooling work
Summary: Improve the Python tooling in the OpenTitan project for register description generation, documentation generation, etc.
OpenTitan contains a range of tools, implemented in Python to help build custom SoCs. e.g. topgen.py, regtool.py, tlgen.py. In general, these could all benefit from further software engineering input - e.g. adding a proper test suite, working with digital designers / design verification engineers to implement new features. e.g. it may be interesting to extend the vendor tool to allow the extraction of a specific piece of IP from the OpenTitan repository and its dependencies.
Create an Ibex-based SoC platform for iCE40 UltraPlus FPGA devices
Summary: Create an Ibex-based demonstration platform using IceStorm, the fully open source Verilog-to-bitstream flow for iCE40 FPGAs .
This project necessarily involves porting the Ibex core to the IceStorm flow, making sure it fits and reasonably maps to iCE40 FPGAs. Then adding memory, timer, UART, SPI (leveraging + adapting existing IP). Finally, creation of the SoC infrastructure: toolchain, linker script, software libs.
Open source logic analyser IP for FPGA
Summary: Build a sigrok compatible logic analyser that can be used in FPGA.
FPGA vendors such as Altera and Xilinx have proprietary logic analyser generators that can be used for FPGA debug. They allow configuration of a wide number of parameters, such as signal widths, depth of buffering and possible triggering modes (from a simple edge trigger to more complex conditions involving multiple signals over several cycles).
Sigrok is an open source software suite for signal analysis, it supports a wide range of devices. This project would build an open source logic analyser generator with similar capabilities to existing proprietary solutions that is compatible with Sigrok. The focus would be on use for FPGA debug but it could also be used with external IO to produce a ‘traditional’ logic analyser or be embedded in an ASIC for post-silicon debug.
By combining the generator with an existing verilog parsing framework a user friendly front end could be created. This would allow a designer to select the signals they want to capture and the necessary logic analyser would be generated with all the required wiring to feed to signals into the analyser.
Proof-of-concept integration of pointer authentication support in Ibex
Summary: Extend the processor pipeline of Ibex with instructions to generate and check pointer authentication codes.
Pointer Authentication uses cryptographic message authentication codes (MACs) both generated and authenticated at runtime to protect the integrity of pointers in order to aggravate attacks targeting arbitrary code execution through malicious manipulation of code and data pointers. This project aims at doing a proof-of-concept integration of pointer authentication into Ibex.
For this project, the actual MAC is considered a black box of configurable latency. The focus lies on integrating pointer authentication into the processor pipeline. To this end, new custom instructions need to be added to generate and authenticate pointers based on the value of the PC, SP and a secret key (including exception handling if authentication fails).
“Simulated” memory controller
Summary: Provide a way to produce realistic performance numbers from FPGA.
It is a common pitfall to misinterpret or incorrectly scale performance numbers derived from benchmarks run on an FPGA-based SoC design. The problem is that your external memory interface is running at a very high speed compared to the core CPU (e.g. a 25MHz core clock speed but external memory running a several hundred MHz). This can be misleading when trying to consider what the performance would be on an ASIC, as the CPU clock speed could be many times higher but the memory frequency be the same or increase by a much smaller amount. The solution is to have a simulation-ready memory controller that will produce delays much closer to a system where the memory interface is running at a much slower speed.