BIBLIOGRAFÍA

By far the easiest way to perform initial setup of your Raspberry Pi is to use the built-in Raspi-Config utility. You can start Raspi-Config from the full-screen Bash environment or from the LXTerminal simply by typing the following:

sudo raspi-config

Doing so presents you with the Raspi-Config text-based interface you saw in Chapter 4. Raspi-Config is actually a user-friendly front end to the config.txt configuration file located in the /etc directory.

Figure 5.7 shows you what the Config.txt file looks like.

FIGURE 5.7 The Raspi-Config utility makes “under the hood” changes to the Config.txt file.

You can see the Raspi-config interface proper in Figure 5.8.

FIGURE 5.8 The Raspberry Pi Software Configuration Tool (Raspi-Config).

You can navigate through Raspi-Config utility by using the keyboard and can use your Up and Down arrow keys or the Tab key to move through the options; press Enter to make a selection.

To leave the main menu and leave Raspi-Config, use the Right Arrow or Tab until you’ve highlighted Finish, and then press Enter.

Let’s close this chapter by walking through each Raspi-config option in greater detail.

Expand Filesystem

You should run this option as soon as possible after flashing your Raspbian SD card. Doing so makes the full space of your SD card available to Raspbian. If you don’t expand the root file system, your Raspbian OS will be limited to a 2GB partition. This result is, of course, quite undesirable if you are using a 32GB SD card!

Change User Password

Everybody with any degree of familiarity with the Raspberry Pi knows that the default username is pi and the default password is raspberry. Thus, if you have any notion of storing confidential data on your Pi, you are best advised to change the password for the pi account immediately.

Remember you can also change the current user’s password at any time by issuing the passwd Terminal command.

You learn how to create additional user accounts in the next chapter.

Enable Boot to Desktop

This option can be used to instruct the Pi to book directly into LXDE instead of stopping at the Terminal prompt. Of course, you need to perform some additional work if you habitually connect to

your Pi remotely like I do. At any rate, Chapter 7 gives you the full skinny on Raspberry Pi connectivity options.

Internationalisation Options

This option opens a submenu that enables you to localize your Pi to its corresponding geographic location. Inside this submenu are three options:

Change Locale: This option enables you to choose your default language and corresponding character set. The Pi is configured for UK English by default, but if you want to make a change, you can do so here. For instance, users located in the United States should select the

en_US.UTF-8 locale.

Change Timezone: The Foundation cut some financial and production corners by not

including a real-time clock on the Raspberry Pi PCB. Accordingly, the Pi needs some help in determining the current time and date. Please be sure to select your proper timezone here, and then as long as the Pi is connected to the Internet, the Pi will periodically synchronize system time with one of the world’s atomic time clock servers.

Keyboard Layout: By default, Raspbian is configured for the UK English keyboard layout.

This makes sense because Raspberry Pi is a UK product. However, you’ll want to change the keyboard layout to match your locale so that you don’t see any unexpected behavior in your typing results. Most commonly, this “unexpected behavior” manifests in, for instance, a US user typing @ and seeing “ (double quote) instead, or typing # and instead seeing the pound sterling symbol.

Note: Internationalisation?

Given the Raspberry Pi is a product of the UK, if you are an American who is accustomed to using Zs instead of Ss (“internationalization” versus “internationalisation”), you should just jolly well get with the global program, wot?

Enable Camera

This option loads the Raspberry Pi camera module drivers and packages, enabling you to make use of the camera board. We’ll spend a lot of time with the Raspi camera in Chapter 16, “Raspberry Pi

We’ll actually learn how to use Rastrack and address any privacy-related concerns you may have in Chapter 17, “Raspberry Pi Security and Privacy Device.”

Overclocking

Overclocking refers to tweaking the CPU operating parameters to force the processor to run at a higher speed than it was originally designed for. The Foundation provides us with helpful overclocking levels to afford us the opportunity to turbo-charge our Pi while at the same time reducing the possibility of frying the chip. Again, this option is discussed in great detail in Chapter 18, “Raspberry Pi Overclocking.”

In the meantime, let me at least let the proverbial cat out of the bag by showing you the overclock levels in Figure 5.9. I’m sure the wording in the dialog “Chose overclock preset” will be fixed in a future firmware update (at least I hope so; sometimes the Pi reveals the lack of spit and polish inherent in grassroots community projects).

FIGURE 5.9 The Foundation makes it pretty easy to overclock the Raspberry Pi CPU.

Advanced Options

This is a submenu that contains the following options:

Overscan: The overscan option enables you to manually adjust the Raspbian screen image.

I’ve never had a problem with the display spilling off the outer border of my monitor, but it’s nice to have correction capability built into the OS.

Hostname: This option enables you to change the name of your Raspberry Pi from its default name of raspberrypi to something of your choosing. I’ve found this option helpful when I’m dealing with a busy network that consists of more than one Raspberry Pi.

Changing any default value in a computer is a recommended security practice because an attacker’s first task is to breach your security by capitalizing upon defaults that were never changed by the owners.

Memory Split: The Pi’s SoC consists of two processing centers: the CPU and the GPU. You can adjust how much memory should be reserved for the GPU by accessing this option. This can have a great impact on system performance depending upon what application you use. This option is also discussed in great detail in Chapter 18.

SSH: Secure Shell (SSH) provides a secure and reliable means of establishing a command prompt session on a remote computer. The SSH server functionality is enabled in Raspbian by default, so you should not need to do anything here.

You learn all about SSH connectivity in Chapter 7.

Update: This option performs an update check for the Raspi-Config script itself.

About raspi-config: This is purely an informational dialog.

Raspi-Config Under the Hood

If you’d like to view the Raspi-Config script source for intellectual curiosity’s sake, run the following Terminal command:

nano /usr/bin/raspi-config

From inspection of the previous command you can draw the following conclusions:

Raspi-Config is actually a Bash shell script (Linux script files typically have the file extension .sh).

The Raspi-Config.sh script is located in the Raspbian file system in the /usr/bin directory.

Just for grins, I show you the partial contents of Raspi-Config.sh in Figure 5.10.

FIGURE 5.10 The Raspi-Config utility is actually the product of a Bash shell script.

Please note that as the Raspberry Pi Foundation adds new features to the Pi, they accordingly update the Raspi-Config utility. Therefore, don’t be surprised if, after running an apt-get upgrade, you see a new Raspi-Config option or a slightly changed menu organization.

Next Steps

At this point I hope you now have enough familiarity with the Linux command-line environment and Raspi-Config utility that you can set up your Raspberry Pi and get into and out of the graphical shell.

In the next chapter, I formally introduce the LXDE graphical environment; doing so should answer some questions that probably popped into your head regarding this interface.

Chapter 6. Debian Linux Fundamentals—Graphical User Interface

“Why run a graphical user interface (GUI, pronounced gooey) at all on a Raspberry Pi?” some computer enthusiasts complain. They’ll tell you that the Pi’s hardware is slow enough as it is. Not to mention that any self-respecting Linux user should be able to accomplish everything he needs by using the command line.

Yes, some Linux aficionados take user experience (UX) matters that seriously. And with the Raspberry Pi they have a point to a certain extent. Shouldn’t we conserve as much of the Pi’s CPU and GPU resources for actual work instead of for drawing fancy windows?

Well, friends, the raw truth of the matter is that many computer users simply prefer the simplicity and intuitiveness of a GUI. Most of us who have grown accustomed to the keyboard and mouse-based navigational methods in OSs such as Microsoft Windows and OS X don’t want to bother learning something new. Thus, the Foundation saw fit to include a graphical shell in the Raspbian Linux distribution. In this chapter you learn how to start, configure, use, and exit the GUI shell.