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 applications 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.