Help! Linux!

In this chapter, we will explain a few basics about Linux. You will also find out how you can change to a graphic user interface and how to reboot and shut down your RevPi.

  • Establish access to the RevPi base module via a terminal.
  • Save your data before doing anything of a critical nature to your system, see Backing Up Data.

Linux Basics

Linux was developed as a multi-user system. Originally, various users worked on a Linux system who were managed by an administrator (user: root).

The Linux file system is structured accordingly. Linux saves files in a file directory tree. It begins with a root directory /(rootfs).

File Contents
/ The root directory is at the very top of the hierarchy.
/bin Programmes that every user can use e.g Shells.
/boot All the files necessary to boot the system.
/dev Device files that are used as an interface to hardware. You can find entries here for all hard disks and their partitions.
/etc Configuration files that contain the programme settings or basic system information.
/home Home directory for all users. A separate file has to be set up for every user that is comparable with “My Documents” on Windows. Every user has full access rights.
/lib The system’s function libraries. Don’t change anything here!
/proc Interface to the kernel. Every current programme is listed in a sub-directory. These files contain information about the latest programme status. There is additionally a directory structure with data about the kernel and the system hardware.
/root The home directory for the system administrator (root). It lies on the root directory so that the system administrator can also access his files whenever a fault makes it impossible to access other partitions.
/sbin Programmes of the system administrator.
/tmp Temporary place for files.
/usr Installed software
/var Status information of the various programmes. Log files are good for searching for errors.
/opt (optional software) Commercial software or very big programmes that don’t directly belong to the system like for example KDE, Firefox usw.

User Administration

When you log on your RevPi, you are automatically in your home directory as User pi@RevPi. You will recognize it by the symbol ~ after your user name. In your home directory, you have the full access rights to all your files. Here is where you can archive and administer, for example, documents, videos or audio files.

You need system administrator rights for some functions. An example is the shutting down the RevPi.

Reboot and Shut Down RevPi

NOTICE
Do not pull the power supply plug to turn the device off. If the system is writing data at the time on the eMMC storage, it may lead in rare cases to the eMMC storage’s filing system being destroyed, thus even making it impossible to boot the system.

By writing sudo before your command, you will be given system administrator rights for the specific command.

  • Enter command sudo reboot to reboot the RevPi.
  • Enter command sudo shutdown to shut down the RevPi.
  • Enter command sudo shutdown –h 0 to shut down the RevPi with no delay.

Linux Graphical User Inerface (GUI)

  • Enter command startx to start GUI.
  • Enter command sudo revpi-config enable gui to boot directly to GUI.

Alternatively, enable / disable boot to GUI with RevPi Status or with Cockpit.

The GUI requires at least 40 MB of RAM. If you only need it occasionally and are not working in desktop mode, only start the GUI when you need it.