2 - Raspberry PI Community Projects

to boot and enter possible parameters to be transferred to it in the process.
For a standard installation, you only need to choose “Install” or “Graphical install” (with the
arrows), then press the Enter key to initiate the remainder of the installation process. If the
DVD-ROM is a “Multi-arch” disk (such as the one included with this book), and the machine has
an Intel or AMD 64 bit processor, the menu options “64 bit install” and “64 bit graphical install”
enable the installation of the 64 bit variant (amd64) instead of the default 32 bit variant (i386).
In practice, the 64 bit version is only relevant on a server rather than a desktop workstation,
since it will cause difficulties with the use of certain non-free software that are released only as
binaries.
GOING FURTHER
32 or 64 bits?
The fundamental difference between 32 and 64 bit systems is the size of memory
addresses. In theory, a 32 bit system can not work with more than 4 GB
of RAM (2 32 bytes). In practice, it is possible to work around this limitation
by using the 686-bigmem kernel variant, so long as the processor handles the
PAE (Physical Address Extension) functionality. Using it does have a notable
influence on system performance, however. This is why it is useful to use the
64 bit mode on a server with a large amount of RAM.
For an office computer (where a few percent difference in performance is negligible),
you must keep in mind that some proprietary programs are not available
in 64 bit versions (such as Skype and the plugin for handling Java applets
in web browsers, for example). It is technically possible to make them work
on 64 bit systems, but you have to install the 32 bit versions with all the necessary
libraries, and oen to use setarch or linux32 (in the util-linux package)
to trick applications regarding the nature of the system. This is very demanding
for a relatively small gain.
IN PRACTICE
Installation alongside an
existing Windows system
If the computer is already running Windows, it is not necessary to delete the
system in order to install Debian. You can have both systems at once, each installed
on a separate disk or partition, and choose which to start when booting
the computer. This configuration is oen called “dual boot”, and the Debian
installation system can set it up. This is done during the hard drive partitioning
stage of installation and while seing up the bootloader (see the sidebars
in those sections).
If you already have a working Windows system, you can even do without the
recovery CD-ROM; Debian offers a Windows program that will download a
light Debian installer and set it up on the hard disk. You then only need to
reboot the computer and choose between normal Windows boot or booting
the installation program. You can also find it on a dedicated website with a
rather explicit name…
➨ http://ftp.debian.org/debian/tools/win32-loader/stable/
➨ http://www.goodbye-microsoft.com/
BACK TO BASICS
Boot loader
The bootloader is a low-level program that is responsible for booting the Linux
kernel just aer the BIOS passes off its control. To handle this task, it must
be able to locate the Linux kernel to boot on the disk. On i386/amd64 architectures,
the two most used programs to perform this task are LILO, the older
Chapter 4 — Installation
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