Asterinas (星绽) OS: A Rust‑Based Framekernel Architecture Combining Macro‑Kernel Performance with Micro‑Kernel Security

On October 22, a collaborative effort among Zhongguancun Laboratory, Ant Group, Peking University, and Southern University of Science and Technology announced the open‑source release of the Asterinas (星绽) system software stack, which includes Asterinas OS and Asterinas Confidential Computing, targeting secure foundations for cloud computing, trustworthy data flow, and AI workloads.

A massive Windows crash in July 2024, caused by a memory‑out‑of‑bounds bug in a CrowdStrike driver, highlighted the severity of C/C++ memory‑safety issues and underscored the industry’s shift toward Rust as a safer systems‑programming language.

Asterinas OS is an industrial‑grade, next‑generation general‑purpose OS kernel built with an innovative framekernel architecture and developed primarily in Rust, offering Linux compatibility while promising superior security.

Traditional macro‑kernel OSes such as Windows and Linux achieve high performance but suffer from large codebases written in unsafe languages, leading to roughly 70% of vulnerabilities being memory‑safety related. Conversely, micro‑kernel designs like seL4 and Google’s Zircon enhance security by minimizing privileged code, but incur performance penalties due to frequent inter‑process communication.

The framekernel architecture introduced by Asterinas combines the strengths of both approaches: it partitions the kernel into a privileged "OS framework" that encapsulates low‑level, potentially unsafe Rust code behind safe APIs, and unprivileged "OS services" written entirely in safe Rust, thus delivering macro‑kernel‑level performance with micro‑kernel‑level security.

By adopting this design, Asterinas OS dramatically reduces the amount of critical (TCB) code—approximately 30% of the total kernel code—far lower than traditional OSes, and empirical studies suggest that as the codebase grows, the proportion of critical code will continue to decline, enhancing overall trustworthiness.

The OS supports x86 and RISC‑V architectures, implements over 170 Linux system calls, and can run common server applications such as Nginx and Redis, positioning it for early adoption in cloud and confidential‑computing data‑center scenarios by 2025.

Benchmarking with LMbench shows Asterinas achieving performance comparable to Linux (average 1.05× relative to Linux), noting that the slight advantage stems partly from a leaner feature set rather than raw speed gains, yet confirming that security improvements do not sacrifice performance.

Asterinas OS is fully open‑source and free; the source code is available at https://github.com/asterinas/asterinas .