Open source design for secure CHERI microcontrollers

lowRISC and SCI Semiconductor have joined forces to unveil the open source Sunburst chip repository, aimed at facilitating the development of secure CHERI microcontrollers. This release marks a significant step towards expediting the creation of commercial microcontrollers utilizing the CHERIoT embedded architecture.

The unveiling of the design repository on Github represents a pivotal moment in the second phase of the Sunburst Project, which is supported by funding from the UK. The repository showcases the CHERIoT-Ibex architecture, a collaborative effort with Microsoft, and is set to be integrated into the ICENI device family from SCI, slated for commercial availability later this year on a 22nm process.

At its core, the CHERI architecture serves as a hardware-based defense mechanism against memory safety vulnerabilities, which are responsible for approximately 70% of reported exploits in the digital landscape.

Dr. Gavin Ferris, CEO of lowRISC in Cambridge, UK, emphasized the importance of addressing security challenges proactively through the CHERIoT-Ibex architecture. He stated, “Our release, in partnership with SCI, of the permissively licensed open source Sunburst Chip repository signifies a significant milestone in making CHERI-based security solutions accessible to the embedded systems market, a key objective of the Sunburst project.”

The initial phase of the Sunburst Project introduced CHERI technology to embedded engineers via the Sonata FPGA board and RTL platform. Subsequent efforts led to the development of an open source SoC top-level, leveraging IP components from the OpenTitan “Earl Grey” chip, currently in production with Google and set to feature in Chromebooks this year. Collaboratively, lowRISC and SCI are also progressing towards the fabrication of a customized version of the Sonata design.

Haydn Povey, Chief Executive of SCI Semiconductor, highlighted the pivotal role of commercial-grade CHERI technology in shaping the landscape of secure computing. He expressed, “Our mission is to provide the market with robust, open source foundations for secure-by-design microcontrollers, enabling differentiation opportunities, akin to what we have achieved with Iceni.”

The Sunburst Chip repository is now accessible to the public on GitHub at github.com/lowRISC/sunburst-chip. Developers and researchers are encouraged to delve into the repository and harness the technology for their own CHERIoT-Ibex based projects. For those eager to experiment with CHERIoT-Ibex, the Sonata low-cost boards are readily available at Mouser.