A run-time detector for violated memory access in embedded systems

Recently, application in embedded systems has increasingly become complex. This requires having tools to prevent or detect memory corruption errors during the software development process. Unfortunately, most of embedded processors lack to be equipped a MMU (Memory Management Units), one of hardware components supporting memory protection mechanism in general purpose computer system, because MMU-based memory protection methods cause embedded system incurred hardware cost and performance penalty. In this paper, an off-chip model is proposed to detect violated memory accesses at run-time without incurring hardware cost. It can efficiently detect errors for RTOS-based applications in cases of stack overflow, reading/writing to code/data segments of the other tasks or violated memory access to OS kernel. The hardware component based on FPGA is also built by hooking on memory system bus to monitor memory accesses. Once error detection phase is completed, the hardware prototype can be detached from the system. Some testbeds are used for this model and give good results.