RISC-V: An open-source instruction set architecture (ISA) from China

RISC-V: An open-source instruction set architecture (ISA) from China

China is rapidly advancing in semiconductor development, with RISC-V emerging as a key player in reducing reliance on Western chip architectures like x86 (Intel/AMD) and ARM. As U.S. sanctions restrict access to advanced technologies, China is turning to open-source RISC-V to build homegrown processors. This article explores China’s RISC-V chips, the operating systems (OS) that run on them, and the challenges ahead.

Why RISC-V? China’s Strategic Shift

RISC-V is an open-source instruction set architecture (ISA), meaning companies can design chips without paying licensing fees to ARM or Intel. This makes it ideal for China’s push for semiconductor self-sufficiency. Key advantages include:

- No export restrictions (unlike ARM, which is subject to U.S. controls).

- Customizable designs for AI, IoT, and high-performance computing.

- Strong government backing under China’s "Made in China 2025" plan.

Major Chinese tech firms like Alibaba, Huawei, and StarFive are leading RISC-V development.

Key Chinese RISC-V Processors

Several Chinese companies have developed RISC-V chips for different applications:

1. Alibaba/T-Head Xuantie Series

- Used in AI and edge computing.

- C910 is a high-performance core comparable to ARM’s Cortex-A73.

2. StarFive JH7110

- A Linux-capable SoC used in development boards like the VisionFive 2.

- Targets embedded systems and single-board computers.

3. Espressif ESP32-C Series

- Low-power RISC-V chips for IoT devices.

- Runs FreeRTOS and Zephyr OS.

4. Loongson (Exploring RISC-V)

- Primarily uses MIPS but is shifting toward RISC-V for future designs.

Operating Systems (OS) for RISC-V

RISC-V supports a variety of operating systems, from embedded real-time OSes to full Linux distributions.

1. Linux-Based OS (Desktop/Server Use)

- Debian & Ubuntu RISC-V – Mainstream Linux distros with official RISC-V ports.

- Fedora RISC-V – Supported by Red Hat for developers.

- openEuler – A Huawei-backed Linux distro for servers.

- Deepin RISC-V – A Chinese desktop OS with a Windows-like interface.

2. Real-Time OS (RTOS) for Embedded/IoT

- FreeRTOS & Zephyr OS – Lightweight OSes for microcontrollers.

- RT-Thread – A Chinese RTOS gaining popularity in smart devices.

- AliOS Things – Alibaba’s IoT-focused OS.

3. Unix-like & Research OSes

- FreeBSD/OpenBSD – Secure, scalable OSes with RISC-V support.

- SeL4 Microkernel – A formally verified OS for security-critical applications.

4. Chinese Domestic OS Efforts

- OpenHarmony (from Huawei) – Supports RISC-V for smart devices.

- SylixOS – A real-time OS used in industrial applications.

5. Windows on RISC-V?

- No official support yet, but Microsoft has experimented with RISC-V for Windows IoT.

Challenges & Risks for China’s RISC-V Ecosystem

Despite progress, China faces hurdles in RISC-V adoption:

1. Software & Driver Support – Many Linux apps still lack optimization.

2. Performance gaps: RISC-V falls behind x86/ARM in PCs and servers.

3. Geopolitical Threats – The U.S. could restrict RISC-V tools (though harder than ARM/x86).

4. Ecosystem Fragmentation – Multiple Chinese RISC-V designs may lead to compatibility issues.

Conclusion: A Promising but Unfinished Journey

China’s bet on RISC-V is a strategic move to achieve chip independence. While the ecosystem is growing fast, it still needs more software support, high-end processors, and industry standardization. If successful, RISC-V could reshape the global semiconductor landscape, with China at the forefront.

Relevant sites

https://riscv.org/industries/risc-v-hpc/