BeagleBone and the root Superuser

By Rui Santos, Luis Miguel Costa Perestrelo

In the Linux community the administrator of the system is called the superuser. For BeagleBone, root is the superuser and is used for privileged tasks, such as installing and updating software, messing around directories with restricted access, and controlling the BeagleBone’s input and output pins.

You don’t need to log in as root, even when you’re not logged in as root, you run programming scripts and commands with root permission. As such, it’s important that you know about what the root superuser is capable of.

To log in as a superuser, type the following command:

debian@beaglebone:~$ sudo su
root@beaglebone:/home/debian#

By default, no password is required to log in as root, but if you’ve defined one, you’re prompted to type it.

As superuser, you have the power to do practically whatever you want. Cool. But that also means the system won’t protect you from yourself: If you’re careless, you may make changes on your board that will be difficult to rectify! For that reason, it’s often considered to be hazardous to work as root. Generally, you should only log in as root when absolutely necessary.

You should only exercise the superuser’s powers when whatever it is that you tried to do as a regular user didn’t work.

The default username and password are debian and temppwd, respectively. Log in as a regular user by entering the following command:

root@beaglebone:~# login debian
Password:
Last login: Wed Apr 23 20:21:20 UTC 2014 on pts/0
Linux beaglebone 3.8.13-bone47 #1 SMP Fri Apr 11 01:36:09 UTC 2014 armv7l
The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
debian@beaglebone:~$

The password text isn’t visible while you’re typing (someone may be looking!) so simply press Enter or Return when you’re done typing.