ASIL-Aware Circular Logger: A Zero-Interference Diagnostic Logging Framework for Safety- Critical Automotive RTOS

Abstract

High loads frequently lead to throttling of diagnostic logging on mixed-criticality automotive ECUs due to blocking and timing interference created by traditional logger designs. This paper delivers ASIL (Automotive Safety Integrity Level)-Aware Circular Logger (AACL) a FreeRTOS-based framework that incorporates hook-based execution-domain knowledge and ASIL-prioritized buffering to eliminate the possibility of blocking once safety-critical execution paths are defined. A closed-form calibrated deferred-latency upper bound is derived from representative automotive task sets; experimental testing used the FreeRTOS GCC_POSIX port with a Cortex-M4 at 168 MHz reference task model with unique benchmark against a naive logger (directly based on mutexes) will provide evidence hosts but not certified timing (in target systems). Results showed no measured ASIL task blocking for the AACL, subordinate deferred latencies (bounded) with quantifiable tightness bounds, significant throughput/drop-rate robustness game over baseline logger provided, only public FreeRTOS API used in implementation and designed for integration into ISO 26262 timing arguments.