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Terminology

Quick reference for terms used across the documentation.

Term Meaning
Offline Lab OS The offline-first operating system built with Buildroot
Package A set of five files per app: .squashfs, .squashfs.roothash, .squashfs.roothash.p7s, .squashfs.verity, .json. Distributed as a .zip archive. The distributable unit
Service A running instance of an installed package on a device
Framework The Bash utility library and boxctl CLI bundled with Offline Lab OS
Node A single device (e.g. Raspberry Pi Zero 2W) running Offline Lab OS
Disco The service discovery and name resolution daemon
Slot One of two root filesystem partitions (A/B) used for atomic updates
Boot partition The FAT32 partition holding firmware, U-Boot, kernel, initramfs, and bootconf.yaml
Overlay partition Holds per-slot overlayfs upper/work directories
/data The persistent read-write partition for user data and package state
bootconf Boot-time configuration tool: reads /data/config/bootconf.yaml at every boot and provisions SSH keys, WiFi, hostname, and user config
boxctl On-device CLI for managing Offline Lab OS (status, updates, network, diagnostics)
appctl On-device CLI for installing and managing app packages
buildctl Developer-side CLI for building, signing, and publishing app packages
sysext systemd system extension: a squashfs image that extends /usr/ or /opt/ at runtime without modifying the read-only rootfs
confext systemd configuration extension: a squashfs image that layers additional config under /etc/ at runtime