Flatpak

Flatpak provides features for application sandboxing and distribution. Applications for the phone will be distributed as flatpaks – packages that can be distributed via repositories. Documentation for the flatpak tool and its flatpak-builder wrapper can be found in the Flatpak documentation.

Versions of these tools provided with modern GNU/Linux distributions should be sufficient. Debian-based distributions provide packages called flatpak and flatpak-builder that can be installed with the following command:

sudo apt -y install flatpak flatpak-builder

The flatpak-builder tool is used to build flatpaks; the flatpak tool is used to install and uninstall flatpaks, manage repositories and keep track of the applications that are available to run.

Cross-Compiling

Building and testing applications locally is straightforward. Cross-compiling applications with Flatpak requires the use of the qemu user mode emulation binaries. On Debian-based platforms these can be installed with the following command:

sudo apt -y install qemu-user-static

This package, or the equivalent on other platforms, is necessary if you want to build applications for the Librem 5 on systems with a processor architecture different to that used by the phone (aarch64).