Ubuntu Continues Expanding RISC-V Support – Now, The $17 Sipeed LicheeRV

Canonical has brought its Ubuntu Linux operating system to another RISC-V system: this week, Sipeed's LicheeRV single board computer.

The announcement marks the software house's latest investment in the open, royalty-free ISA. To date, Ubuntu runs on numerous RISC-V systems, including those from SiFive, Clockwork, Microchip, StarFive, and now Sipeed. We're also happy to note that other flavors of Linux, such as Debian, run on RISC-V hardware, too.

The LicheeRV dev board is very modest, performance wise, and aimed at embedded electronics, Internet of Things, and low-power machine-learning applications. The diminutive system can be found online for less than $17 and is powered by a 1GHz Allwinner D1 processor with a single 64-bit RV64GCV C906 core and 512MB of DDR3 memory.

The CPU core itself is open source and was developed by Alibaba's T-Head division. Notable features include an integrated Tensilica HiFi4 digital signal processor and support for 4K H.265 video decoding.

Similar to the Raspberry Pi Compute Module 3, which used a SODIMM connector, Sipeed's LicheeRV is designed to slot into I/O breakout boards using a modified M.2B-key edge connector. However, developers can also interact with the RISC-V SBC using the onboard USB-debugging interface.

"It is a first but significant step for our partnership, and we will continue to collaborate with Canonical to provide a powerful and affordable RISC-V SBC," Ji Yaping CEO of Sipeed Tech said in a statement.

• China may prove Arm wrong about RISC-V's role in the datacenter
• SiFive RISC-V CPU cores to power NASA's next spaceflight computer
• Seagate says it's designed two of its own RISC-V CPU cores – and they'll do more than just control storage drives
• Arm execs: We respect RISC-V but it's not a rival in the datacenter

Taking a RISC?

RISC-V architectures have gained considerable attention and funding in recent years. The architecture was good enough that NASA plans to incorporate SiFive's RV core designs into its High-Performance Spaceflight Computer currently under development.

And just this week RISC-V International, the governing body behind the ISA, touted the progress made bringing the Android operating system to the architecture.

However, compared to more established processor core families like Arm, x86 or Power, RISC-V remains in its infancy and has largely been roaming among development and FPGA boards, Internet of Things devices, and embedded applications. Seagate and Western Digital, for example, are exploring the RISC-V architecture for embedded storage controllers. Google, Imagination, Nvidia, and Apple are said to be taking an interest if not already using it.

But as Forrester analyst Glenn O'Donnell recently told The Register, while many dismiss RISC-V as being underpowered, there is nothing stopping someone from designing a high-performance processor based on the architecture.

And extensions can be added to the ISA to overcome any weak spots in the instruction set that would hold back a end-end core.

Then there's the big issue of software compatibility and stability.

"Running stable software on new boards can still be challenging," Canonical noted.

"RISC-V has a lot of potential and is becoming a competitive ISA in multiple markets. With this premise in mind, porting Ubuntu to RISC-V to become the reference OS for early adopters was a natural choice."

RISC-V isn't unique in this department. Arm took years to garner sufficient software support to be practical in mainstream desktop and server applications.

Canonical's latest release, Ubuntu 22.10, is now available for download on its website for a variety of RISC-V platforms including the LicheeRV dev board.

The extension of Canonical's popular Linux OS to more RISC-V platforms comes amid a drought of Arm SBCs like the Raspberry Pi 4, Compute Module, and Zero, which have seen spotty availability over the past year as the Raspberry Pi Foundation prioritizes industrial customers. Support for familiar operating environments, like Ubuntu, could make these RISC-V-based systems a more attractive alternative for developers and tinkerers alike. ®