Delta Updates for Embedded Systems

Abstract

Many resource-constrained Internet of Things units are used in a manner which makes them inaccessible via cable and at the same time unable to receive large amounts of data using radio transmissions. Upgrading firmware is hence difficult or in some cases impossible. Integrating support for delta updates in the unit is a potential solution to this problem, as it significantly reduces the payload during an upgrade scenario. However, as of now there is no open-source solution for delta upgrades in embedded systems. This thesis aims to show that such a solution is achievable and that it causes a significant payload reduction. This proof of concept is realized through the development of a Zephyr application with delta upgrade support. Using this application firmware upgrades are performed using only 2.6 percent of the amount of external data needed for standard upgrades.