When Radiation Meets Linux: Analyzing Soft Errors in Linux on COTS SoCs under Proton Irradiation

Abstract: The increasing use of Linux on commercial off-the-shelf (COTS) system-on-chip (SoC) in spaceborne computing inherits COTS susceptibility to radiation-induced failures like soft errors. Modern SoCs exacerbate this issue as aggressive transistor scaling reduces critical charge thresholds to induce soft errors and increases radiation effects within densely packed transistors, degrading overall reliability. Linux's monolithic architecture amplifies these risks, as tightly coupled kernel subsystems propagate errors to critical components (e.g., memory management), while limited error-correcting code (ECC) offers minimal mitigation. Furthermore, the lack of public soft error data from irradiation tests on COTS SoCs running Linux hinders reliability improvements. This study evaluates proton irradiation effects (20-50 MeV) on Linux across three COTS SoC architectures: Raspberry Pi Zero 2 W (40 nm CMOS, Cortex-A53), NXP i MX 8M Plus (14 nm FinFET, Cortex-A53), and OrangeCrab (40 nm FPGA, RISC-V). Irradiation results show the 14 nm FinFET NXP SoC achieved 2-3x longer Linux uptime without ECC memory versus both 40 nm CMOS counterparts, partially due to FinFET's reduced charge collection. Additionally, this work presents the first cross-architecture analysis of soft error-prone Linux kernel components in modern SoCs to develop targeted mitigations. The findings establish foundational data on Linux's soft error sensitivity in COTS SoCs, guiding mission readiness for space applications.

Analyzing Soft Errors in Linux on COTS SoCs under Proton Irradiation

The paper "When Radiation Meets Linux: Analyzing Soft Errors in Linux on COTS SoCs under Proton Irradiation" presents an in-depth study on the susceptibility of Linux operating systems running on commercial off-the-shelf (COTS) System-on-Chip (SoC) devices to soft errors induced by proton irradiation. The motivation for this research is driven by the increasing adoption of Linux on COTS SoCs in space applications, where radiation-induced soft errors pose significant reliability challenges. The research focuses on evaluating proton irradiation effects on Linux-based systems across three COTS SoC architectures: the Raspberry Pi Zero 2 W, NXP i.MX 8M Plus, and OrangeCrab FPGA embedded with a RISC-V processor.

Key Findings and Numerical Results

The study provides detailed cross-architecture analysis of soft error vulnerabilities in Linux kernel components. Proton irradiation, ranging from 20 to 58 MeV, was employed to evaluate the soft error rates across the selected platforms. A noteworthy finding is that the NXP i.MX 8M Plus, based on a 14 nm FinFET process, demonstrated resilience with 2–3 times longer Linux uptime compared to its 40 nm counterparts. This result aligns with established semiconductor physics, where FinFET architectures provide improved charge control and reduced error rates due to their 3D gate structures.

For the Raspberry Pi Zero 2 W and OrangeCrab FPGA, the failure cross-sections were calculated to be significantly higher, indicating a greater susceptibility to soft errors. The research quantified these vulnerabilities and constructed a comprehensive dataset outlining the Linux components most affected by radiation-induced errors.

Implications for Spaceborne Computing

The implications of the study are substantial for spaceborne computing. Ensuring reliability of Linux on COTS hardware requires targeted mitigation strategies, which this research begins to outline. The proposed mitigations include enhancing software resilience through error detection and correction strategies, implementing watchdog timers for fault recovery, and advocating for the deployment of hardware with inherent radiation-resistance like FinFET-based SoCs.

The practical applications of this work lie in informing satellite operators and designers on the selection of SoC platforms and outlining preventative measures to mitigate soft error impacts. Moreover, the study’s results can guide system architects in designing robust space systems integrating Linux on COTS hardware, especially for missions sensitive to radiation environments.

Theoretical Advances and Future Directions

Theoretically, the paper advances the understanding of how contemporary computing systems can be made more resilient against the effects of space radiation. The delineation of specific Linux kernel subsystems prone to soft errors opens paths for developing fine-grained, architecture-specific countermeasures. For example, the integration of ECC memory and the adoption of system-level redundancy could substantially improve mission-critical applications' fault tolerance.

The study sets a benchmark for future research, encouraging further exploration into soft error hardening techniques tailored for the Linux operating system running on diverse SoC architectures. Future work could involve advancing the proposed resiliency tactics such as deploying hybrid software and hardware solutions, optimizing ECC implementations for performance without excessive overhead, and exploring new materials and SoC designs that leverage beyond the FinFET approach for enhanced reliability.

In conclusion, this paper provides a systematic exploration of soft error impacts on Linux within COTS SoCs under proton irradiation, with tangible insights into improving reliability. It serves as a foundational work directing future engineering and research endeavors in the field of AI applications and space exploration missions reliant on commercial computing technologies.