This repository contains a build system for FullPageOS, a Raspberry Pi distribution that boots directly into a full-screen Chromium browser kiosk displaying a configurable webpage. The build process uses CustomPiOS to modify a Raspbian base image, installing Chromium, lighttpd (with FullPageDashboard), x11vnc for VNC access, and a set of scripts that manage the browser startup, URL resolution (with serial number substitution), page refresh, and crash recovery. The resulting OS image is designed for digital signage or single-purpose web displays. The repo includes a comprehensive testing framework with end-to-end tests that run in QEMU, verifying Chromium launch, lighttpd service, emoji rendering, and translation disabling via screenshot pixel analysis. The CI pipeline builds images for armhf and arm64 and runs the e2e tests automatically. While the core build scripts are functional and well-structured, they are tightly coupled to the CustomPiOS ecosystem and not independently reusable. The testing components, particularly the screenshot analysis and headless Chromium rendering tests, exhibit higher craftsmanship and could be adapted for other kiosk image validation efforts.