Energy-Efficient Progressive Remote Update for Flash-Based Firmware of Networked Embedded Systems

Abstract

Firmware update over a network connection is an essential but expensive feature for many embedded systems due to not only the relatively high power consumption and limited bandwidth, but also page-granular erasure before rewriting to flash memory. This work proposes a page-level, link-time technique that minimizes not only the size of patching scripts but also perturbation to the firmware memory, over the entire sequence of updates in the system’s lifetime. We propose a tool that first clusters functions to minimize caller-callee dependency across pages, and then orders the functions within each page to minimize intrapage perturbation. Experimental results show our technique to reduce the energy consumption of firmware update by 30--42% over the state-of-the-art. Most importantly, this is the first work that has ever shown to evolve well over 41 revisions of a real-world open-source real-time operating system.