Modules

One of the main features in CustomPiOS is writing modules. A module is a structured piece of code that adds a function to a distro.

Setting Modules

To set what the distro does, you can add and remove modules. The modules are defined in the MODULES variable set in your distro <distro folder>/src/config file. Modules can be nested, the enables you to provide namespaces or run cleanup functions after other module have run. For example MODULES=base(network(octopi, picamera)), in this example base will start first, and end last, network will start second and end one before last, octopi will start third and end first.

Writing Modules

• Module are places in folders whose names are small letters and with hyphens.
• The can be placed either in CustomPiOS/src/modules or <distro folder>/src/modules.

See the example module in the example disro.

Modules are made from 3 parts:

• start_chroot_script / end_chroot_script
• filesystem folder
• config file

List of Standard library modules

• base - This is the base module you must have in your distro. It sets what image is selected and critical things in the distro
• disable-services - Disables systemd services to start up right after installing them. If your module is installing something, say lighttpd. You should wrap your module with this one. Eg disable-services(lighttpd).
• ffmpeg - Module builds and installs latest ffmpeg from git
• gui - Lets you add a gui that will start on boot, autologin and GPU out of the box.
• kernel - Builds and installs a custom kernel. Warning: building a kernel can take as long as 6 hours. And with two it takes 12 hours. If you are building them a lot its recommended to create a base image and build on top of that. See RealtimePi for usage example.
• network - This module is enabled by default, it creates a file in /boot/${DIST_NAME}-network.txt and /boot/${DIST_NAME}-wpa-supplicant.txt that lets you set up the wifi configuration from a text file that is accessable even from a windows machine.
• password-for-sudo - Revert Raspbian's "no password for sudo"
• raspicam - Enables the pi camera by default