The Android Update Problem: An Empirical Study

TL;DR

This study analyzes the modifications made by phone vendors to Android, especially in LineageOS, to understand change overlap and assess the potential for automated merging tools to streamline Android updates.

Contribution

It provides an empirical analysis of vendor modifications to Android and develops a tool chain to study change overlap, highlighting opportunities for automation.

Findings

83% of subsystems modified by LineageOS are also changed in the next Android release.

56% of LineageOS changes could potentially be automated.

Developed a tool chain for analyzing Android modifications and their overlaps.

Abstract

Many phone vendors use Android as their underlying OS, but often extend it to add new functionality and to make it compatible with their specific phones. When a new version of Android is released, phone vendors need to merge or re-apply their customizations and changes to the new release. This is a difficult and time-consuming process, which often leads to late adoption of new versions. In this paper, we perform an empirical study to understand the nature of changes that phone vendors make, versus changes made in the original development of Android. By investigating the overlap of different changes, we also determine the possibility of having automated support for merging them. We develop a publicly available tool chain, based on a combination of existing tools, to study such changes and their overlap. As a proxy case study, we analyze the changes in the popular community-based variant of Android, LineageOS, and its corresponding Android versions. We investigate and report the common types of changes that occur in practice. Our findings show that 83% of subsystems modified by LineageOS are also modified in the next release of Android. By taking the nature of overlapping changes into account, we assess the feasibility of having automated tool support to help phone vendors with the Android update problem. Our results show that 56% of the changes in LineageOS have the potential to be safely automated.