BUBBLE: an FPGA-Based Timing Fault Injector

Nowadays, several industrial domains, including avionics, railway, and automotive, are looking into multicore platforms with programmable logic as effective means to host ap-plications with different levels of criticality, i.e., mixed -criticality systems. However, temporal isolation and constraints in such applications pose significant security and safety concerns. In this paper, we introduce BUBBLE, a novel FPGA-based timing fault injector capable of injecting arbitrary delays (i.e., bubbles) to evaluate the temporal properties and fault tolerance of mixed-criticality systems. BUBBLE offers high control over injections and a predictable overhead. We implemented a prototype of BUBBLE running on Xilinx Zynq Ultrascale+ (ZCU104), and conducted a preliminary experimental analysis to demonstrate BUBBLE effectiveness in injecting permanent and transient temporal faults with low and predictable overhead.