en/handbook/hb-install-system.xml

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE sections SYSTEM "/dtd/book.dtd">

<!-- The content of this document is licensed under the CC-BY-SA license -->
<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->

<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-install-system.xml,v 1.118 2011/03/16 07:43:58 nightmorph Exp $ -->

<sections>

<abstract>
After installing and configuring a stage3, the eventual result is that you
have a Gentoo base system at your disposal. This chapter describes how
to progress to that state.
</abstract>

<version>11</version>
<date>2011-08-03</date>

<section>
<title>Chrooting</title>
<subsection>
<title>Optional: Selecting Mirrors</title>
<body>

<p>
In order to download source code quickly it is recommended to select a fast
mirror. Portage will look in your <path>make.conf</path> file for the
GENTOO_MIRRORS variable and use the mirrors listed therein. You can surf to
our <uri link="/main/en/mirrors.xml">mirror list</uri> and search
for a mirror (or mirrors) close to you (as those are most frequently the 
fastest ones), but we provide a nice tool called <c>mirrorselect</c> which
provides you with a nice interface to select the mirrors you want. Just 
navigate to the mirrors of choice and press spacebar to select one or more
mirrors.
</p>
  
<pre caption="Using mirrorselect for the GENTOO_MIRRORS variable">
# <i>mirrorselect -i -o &gt;&gt; /mnt/gentoo/etc/make.conf</i>
</pre>

<p>
A second important setting is the SYNC setting in <path>make.conf</path>. This
variable contains the rsync server you want to use when updating your Portage
tree (the collection of ebuilds, scripts containing all the information Portage
needs to download and install software). Although you can manually enter a SYNC
server for yourself, <c>mirrorselect</c> can ease that operation for you:
</p>

<pre caption="Selecting an rsync mirror using mirrorselect">
# <i>mirrorselect -i -r -o &gt;&gt; /mnt/gentoo/etc/make.conf</i>
</pre>

<p>
After running <c>mirrorselect</c> it is adviseable to double-check the settings
in <path>/mnt/gentoo/etc/make.conf</path> !
</p>

<note>
If you want to manually set a SYNC server in <path>make.conf</path>, you should
check out the <uri link="/main/en/mirrors-rsync.xml">community mirrors
list</uri> for the mirrors closest to you. We recommend choosing a
<e>rotation</e>, such as <c>rsync.us.gentoo.org</c>, rather than choosing a
single mirror. This helps spread out the load and provides a failsafe in case a
specific mirror is offline.
</note>

</body>
</subsection>
<subsection>
<title>Copy DNS Info</title>
<body>

<p>
One thing still remains to be done before we enter the new environment and that
is copying over the DNS information in <path>/etc/resolv.conf</path>. You need
to do this to ensure that networking still works even after entering the new
environment. <path>/etc/resolv.conf</path> contains the nameservers for your
network.
</p>

<pre caption="Copy over DNS information">
<comment>(The "-L" option is needed to make sure we don't copy a symbolic link)</comment>
# <i>cp -L /etc/resolv.conf /mnt/gentoo/etc/</i>
</pre>

</body>
</subsection>
<subsection test="not(func:keyval('arch')='IA64')">
<title>Mounting the /proc and /dev Filesystems</title>
<body>

<p>
In a few moments, we will change the Linux root towards the new location. To
make sure that the new environment works properly, we need to make certain file
systems available there as well.
</p>

<p>
Mount the <path>/proc</path> filesystem on <path>/mnt/gentoo/proc</path> to
allow the installation to use the kernel-provided information within the
chrooted environment, and then mount-bind the <path>/dev</path> filesystem.
</p>

<pre caption="Mounting /proc and /dev">
# <i>mount -t proc none /mnt/gentoo/proc</i>
# <i>mount --rbind /dev /mnt/gentoo/dev</i>
</pre>

</body>
</subsection>
<subsection test="func:keyval('arch')='IA64'">
<title>Mounting the /proc, /sys and /dev Filesystems</title>
<body>

<p>
Mount the <path>/proc</path> filesystem on <path>/mnt/gentoo/proc</path> to
allow the installation to use the kernel-provided information within the
chrooted environment, and then mount-bind the <path>/dev</path> and
<path>/sys</path> filesystems.
</p>

<pre caption="Mounting /proc /sys and /dev">
# <i>mount -t proc none /mnt/gentoo/proc</i>
# <i>mount --rbind /dev /mnt/gentoo/dev</i>
# <i>mount --rbind /sys /mnt/gentoo/sys</i>
</pre>

</body>
</subsection>
<subsection>
<title>Entering the new Environment</title>
<body>

<p>
Now that all partitions are initialized and the base environment
installed, it is time to enter our new installation environment by
<e>chrooting</e> into it. This means that we change from the current
installation environment (Installation CD or other installation medium) to your
installation system (namely the initialized partitions).
</p>

<p>
This chrooting is done in three steps. First we will change the root
from <path>/</path> (on the installation medium) to <path>/mnt/gentoo</path> 
(on your partitions) using <c>chroot</c>. Then we will create a new environment
using <c>env-update</c>, which essentially creates environment variables.
Finally, we load those variables into memory using <c>source</c>.
</p>

<pre caption = "Chrooting into the new environment">
# <i>chroot /mnt/gentoo /bin/bash</i>
# <i>env-update</i>
>> Regenerating /etc/ld.so.cache...
# <i>source /etc/profile</i>
# <i>export PS1="(chroot) $PS1"</i>
</pre>

<p>
Congratulations! You are now inside your own Gentoo Linux environment.
Of course it is far from finished, which is why the installation still
has some sections left :-)
</p>

</body>
</subsection>
</section>

<section>
<title>Configuring Portage</title>
<subsection>
<title>Updating the Portage tree</title>
<body>

<p>
You should now update your Portage tree to the latest version. <c>emerge 
--sync</c> does this for you.
</p>

<pre caption="Updating the Portage tree">
# <i>emerge --sync</i>
<comment>(If you're using a slow terminal like some framebuffers or a serial
console, you can add the --quiet option to speed up this process:)</comment>
# <i>emerge --sync --quiet</i>
</pre>

<p>
If you are behind a firewall that blocks rsync traffic, you can use
<c>emerge-webrsync</c> which will download and install a portage snapshot for
you.
</p>

<p>
If you are warned that a new Portage version is available and that you should
update Portage, you should do it now using <c>emerge --oneshot portage</c>.
</p>

</body>
</subsection>
<subsection>
<title>Choosing the Right Profile</title>
<body>

<p>
First, a small definition is in place.
</p>

<p>
A profile is a building block for any Gentoo system. Not only does it specify
default values for USE, CFLAGS and other important variables, it also locks
the system to a certain range of package versions. This is all maintained by the
Gentoo developers.
</p>

<p>
Previously, such a profile was untouched by the users. However, there may be
certain situations in which you may decide a profile change is necessary.
</p>

<p>
You can see what profile you are currently using with the following command:
</p>

<pre caption="Verifying system profile">
# <i>eselect profile list</i>
Available profile symlink targets:
  [1]   <keyval id="profile"/> *
  [2]   <keyval id="profile"/>/desktop
  [3]   <keyval id="profile"/>/server
</pre>

<p>
The default profile will provide you with a Linux 2.6-based system. This is the
recommended default, but you have the option of choosing another profile too.
</p>

<p>
There are also <c>desktop</c> and <c>server</c> subprofiles available for some
architectures. Running <c>eselect profile list</c> will show all available
profiles.
</p>

<p>
After viewing the available profiles for your architecture, you can use a
different one if you wish:
</p>

<pre caption="Changing profiles">
# <i>eselect profile set 2</i>
</pre>

<p test="func:keyval('arch')='AMD64'">
If you want to have a pure 64-bit environment, with no 32-bit applications or
libraries, you should use a non-multilib profile:
</p>

<pre test="func:keyval('arch')='AMD64'" caption="Switching to a non-multilib profile">
# <i>eselect profile list</i>
Available profile symlink targets:
  [1]   <keyval id="profile"/> *
  [2]   <keyval id="profile"/>/desktop
  [3]   <keyval id="profile"/>/no-multilib
  [4]   <keyval id="profile"/>/server
<comment>(Choose the no-multilib profile)</comment>
# <i>eselect profile set 3</i>
<comment>(Verify the change)</comment>
# <i>eselect profile list</i>
Available profile symlink targets:
  [1]   <keyval id="profile"/>
  [2]   <keyval id="profile"/>/desktop
  [3]   <keyval id="profile"/>/no-multilib *
  [4]   <keyval id="profile"/>/server
</pre>

<note>
The <c>developer</c> subprofile is specifically for Gentoo Linux development
tasks. It is <e>not</e> meant to help set up general development environments.
</note>

</body>
</subsection>
<subsection id="configure_USE">
<title>Configuring the USE variable</title>
<body>

<p>
<c>USE</c> is one of the most powerful variables Gentoo provides to its users.
Several programs can be compiled with or without optional support for certain
items. For instance, some programs can be compiled with gtk-support, or with
qt-support. Others can be compiled with or without SSL support. Some programs
can even be compiled with framebuffer support (svgalib) instead of X11 support
(X-server).
</p>

<p>
Most distributions compile their packages with support for as much as possible,
increasing the size of the programs and startup time, not to mention an enormous
amount of dependencies. With Gentoo you can define what options a package 
should be compiled with. This is where <c>USE</c> comes into play.
</p>

<p>
In the <c>USE</c> variable you define keywords which are mapped onto
compile-options. For instance, <e>ssl</e> will compile ssl-support in the
programs that support it. <e>-X</e> will remove X-server support (note the
minus sign in front). <e>gnome gtk -kde -qt4</e> will compile your
programs with gnome (and gtk) support, and not with kde (and qt) support,
making your system fully tweaked for GNOME.
</p>

<p>
The default <c>USE</c> settings are placed in the <path>make.defaults</path> 
files of your profile. You will find <path>make.defaults</path> files in the
directory which <path>/etc/make.profile</path> points to and all parent 
directories as well. The default <c>USE</c> setting is the sum of all <c>USE</c>
settings in all <path>make.defaults</path> files. What you place in
<path>/etc/make.conf</path> is calculated against these defaults settings. If
you add something to the <c>USE</c> setting, it is added to the default list. If
you remove something from the <c>USE</c> setting (by placing a minus sign in
front of it) it is removed from the default list (if it was in the default list
at all). <e>Never</e> alter anything inside the <path>/etc/make.profile</path>
directory; it gets overwritten when you update Portage!
</p>

<p>
A full description on <c>USE</c> can be found in the second part of the Gentoo
Handbook, <uri link="?part=2&amp;chap=2">USE flags</uri>. A full description on
the available USE flags can be found on your system in
<path>/usr/portage/profiles/use.desc</path>. 
</p>

<pre caption="Viewing available USE flags">
# <i>less /usr/portage/profiles/use.desc</i>
<comment>(You can scroll using your arrow keys, exit by pressing 'q')</comment>
</pre>

<p>
As an example we show a <c>USE</c> setting for a KDE-based system with DVD, ALSA
and CD Recording support:
</p>

<pre caption="Opening /etc/make.conf">
# <i>nano -w /etc/make.conf</i>
</pre>

<pre caption="USE setting">
USE="-gtk -gnome qt4 kde dvd alsa cdr"
</pre>

</body>
</subsection>
<subsection>
<title>Optional: glibc Locales</title>
<body>

<p>
You will probably only use one or maybe two locales on your system. You can
specify locales you will need in <path>/etc/locale.gen</path>.
</p>

<pre caption="Opening /etc/locale.gen">
# <i>nano -w /etc/locale.gen</i>
</pre>

<p>
The following locales are an example to get both English (United States) and
German (Germany) with the accompanying character formats (like UTF-8).
</p>

<pre caption="Specify your locales">
en_US ISO-8859-1
en_US.UTF-8 UTF-8
de_DE ISO-8859-1
de_DE@euro ISO-8859-15
</pre>

<p>
The next step is to run <c>locale-gen</c>. It will generate all the locales you
have specified in the <path>/etc/locale.gen</path> file.
</p>

<p>
Now continue with <uri link="?part=1&amp;chap=7">Configuring the Kernel</uri>.
</p>

</body>
</subsection>
</section>
</sections>
1	swift	1.26	<?xml version='1.0' encoding='UTF-8'?>
2			<!DOCTYPE sections SYSTEM "/dtd/book.dtd">
3
4	swift	1.6	<!-- The content of this document is licensed under the CC-BY-SA license -->
5	nightmorph	1.93	<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
6	swift	1.6
7	jkt	1.119	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-install-system.xml,v 1.118 2011/03/16 07:43:58 nightmorph Exp $ -->
8	swift	1.11
9	swift	1.3	<sections>
10	swift	1.56
11	neysx	1.101	<abstract>
12			After installing and configuring a stage3, the eventual result is that you
13			have a Gentoo base system at your disposal. This chapter describes how
14			to progress to that state.
15			</abstract>
16
17	jkt	1.119	<version>11</version>
18			<date>2011-08-03</date>
19	swift	1.56
20	swift	1.1	<section>
21	swift	1.3	<title>Chrooting</title>
22	swift	1.1	<subsection>
23	swift	1.2	<title>Optional: Selecting Mirrors</title>
24			<body>
25
26			<p>
27	swift	1.70	In order to download source code quickly it is recommended to select a fast
28			mirror. Portage will look in your <path>make.conf</path> file for the
29			GENTOO_MIRRORS variable and use the mirrors listed therein. You can surf to
30			our <uri link="/main/en/mirrors.xml">mirror list</uri> and search
31			for a mirror (or mirrors) close to you (as those are most frequently the
32			fastest ones), but we provide a nice tool called <c>mirrorselect</c> which
33	jkt	1.119	provides you with a nice interface to select the mirrors you want. Just
34			navigate to the mirrors of choice and press spacebar to select one or more
35			mirrors.
36	swift	1.70	</p>
37
38			<pre caption="Using mirrorselect for the GENTOO_MIRRORS variable">
39			# <i>mirrorselect -i -o >> /mnt/gentoo/etc/make.conf</i>
40			</pre>
41
42			<p>
43			A second important setting is the SYNC setting in <path>make.conf</path>. This
44			variable contains the rsync server you want to use when updating your Portage
45			tree (the collection of ebuilds, scripts containing all the information Portage
46			needs to download and install software). Although you can manually enter a SYNC
47			server for yourself, <c>mirrorselect</c> can ease that operation for you:
48	swift	1.2	</p>
49
50	swift	1.70	<pre caption="Selecting an rsync mirror using mirrorselect">
51			# <i>mirrorselect -i -r -o >> /mnt/gentoo/etc/make.conf</i>
52	swift	1.2	</pre>
53
54			<p>
55	swift	1.70	After running <c>mirrorselect</c> it is adviseable to double-check the settings
56			in <path>/mnt/gentoo/etc/make.conf</path> !
57	swift	1.2	</p>
58
59	nightmorph	1.113	<note>
60			If you want to manually set a SYNC server in <path>make.conf</path>, you should
61			check out the <uri link="/main/en/mirrors-rsync.xml">community mirrors
62			list</uri> for the mirrors closest to you. We recommend choosing a
63			<e>rotation</e>, such as <c>rsync.us.gentoo.org</c>, rather than choosing a
64			single mirror. This helps spread out the load and provides a failsafe in case a
65			specific mirror is offline.
66			</note>
67
68	swift	1.2	</body>
69	swift	1.3	</subsection>
70			<subsection>
71	swift	1.5	<title>Copy DNS Info</title>
72			<body>
73
74			<p>
75	swift	1.24	One thing still remains to be done before we enter the new environment and that
76			is copying over the DNS information in <path>/etc/resolv.conf</path>. You need
77	swift	1.5	to do this to ensure that networking still works even after entering the new
78			environment. <path>/etc/resolv.conf</path> contains the nameservers for your
79			network.
80			</p>
81
82			<pre caption="Copy over DNS information">
83	swift	1.35	<comment>(The "-L" option is needed to make sure we don't copy a symbolic link)</comment>
84	nightmorph	1.107	# <i>cp -L /etc/resolv.conf /mnt/gentoo/etc/</i>
85	swift	1.18	</pre>
86
87			</body>
88			</subsection>
89	nightmorph	1.105	<subsection test="not(func:keyval('arch')='IA64')">
90	neysx	1.88	<title>Mounting the /proc and /dev Filesystems</title>
91	swift	1.43	<body>
92
93			<p>
94	jkt	1.119	In a few moments, we will change the Linux root towards the new location. To
95			make sure that the new environment works properly, we need to make certain file
96			systems available there as well.
97			</p>
98
99			<p>
100	swift	1.43	Mount the <path>/proc</path> filesystem on <path>/mnt/gentoo/proc</path> to
101	neysx	1.88	allow the installation to use the kernel-provided information within the
102			chrooted environment, and then mount-bind the <path>/dev</path> filesystem.
103	swift	1.43	</p>
104
105	neysx	1.88	<pre caption="Mounting /proc and /dev">
106	swift	1.43	# <i>mount -t proc none /mnt/gentoo/proc</i>
107	nightmorph	1.118	# <i>mount --rbind /dev /mnt/gentoo/dev</i>
108	swift	1.43	</pre>
109
110			</body>
111			</subsection>
112	nightmorph	1.105	<subsection test="func:keyval('arch')='IA64'">
113			<title>Mounting the /proc, /sys and /dev Filesystems</title>
114			<body>
115
116			<p>
117			Mount the <path>/proc</path> filesystem on <path>/mnt/gentoo/proc</path> to
118			allow the installation to use the kernel-provided information within the
119			chrooted environment, and then mount-bind the <path>/dev</path> and
120			<path>/sys</path> filesystems.
121			</p>
122
123			<pre caption="Mounting /proc /sys and /dev">
124			# <i>mount -t proc none /mnt/gentoo/proc</i>
125	nightmorph	1.118	# <i>mount --rbind /dev /mnt/gentoo/dev</i>
126			# <i>mount --rbind /sys /mnt/gentoo/sys</i>
127	nightmorph	1.105	</pre>
128
129			</body>
130			</subsection>
131	swift	1.43	<subsection>
132	swift	1.2	<title>Entering the new Environment</title>
133	swift	1.1	<body>
134
135			<p>
136	swift	1.19	Now that all partitions are initialized and the base environment
137	swift	1.1	installed, it is time to enter our new installation environment by
138	swift	1.9	<e>chrooting</e> into it. This means that we change from the current
139	swift	1.72	installation environment (Installation CD or other installation medium) to your
140	swift	1.19	installation system (namely the initialized partitions).
141	swift	1.1	</p>
142
143			<p>
144			This chrooting is done in three steps. First we will change the root
145	swift	1.2	from <path>/</path> (on the installation medium) to <path>/mnt/gentoo</path>
146			(on your partitions) using <c>chroot</c>. Then we will create a new environment
147			using <c>env-update</c>, which essentially creates environment variables.
148	swift	1.1	Finally, we load those variables into memory using <c>source</c>.
149			</p>
150
151			<pre caption = "Chrooting into the new environment">
152			# <i>chroot /mnt/gentoo /bin/bash</i>
153			# <i>env-update</i>
154	neysx	1.92	>> Regenerating /etc/ld.so.cache...
155	swift	1.1	# <i>source /etc/profile</i>
156	rane	1.87	# <i>export PS1="(chroot) $PS1"</i>
157	swift	1.1	</pre>
158
159			<p>
160			Congratulations! You are now inside your own Gentoo Linux environment.
161	swift	1.10	Of course it is far from finished, which is why the installation still
162	swift	1.1	has some sections left :-)
163			</p>
164
165			</body>
166	swift	1.3	</subsection>
167	swift	1.85	</section>
168
169			<section>
170			<title>Configuring Portage</title>
171	swift	1.3	<subsection>
172	swift	1.64	<title>Updating the Portage tree</title>
173	swift	1.2	<body>
174
175			<p>
176	swift	1.69	You should now update your Portage tree to the latest version. <c>emerge
177			--sync</c> does this for you.
178	swift	1.2	</p>
179
180	dertobi123	1.40	<pre caption="Updating the Portage tree">
181	cam	1.50	# <i>emerge --sync</i>
182	neysx	1.78	<comment>(If you're using a slow terminal like some framebuffers or a serial
183			console, you can add the --quiet option to speed up this process:)</comment>
184			# <i>emerge --sync --quiet</i>
185	swift	1.13	</pre>
186
187			<p>
188	swift	1.75	If you are behind a firewall that blocks rsync traffic, you can use
189			<c>emerge-webrsync</c> which will download and install a portage snapshot for
190			you.
191			</p>
192
193			<p>
194	swift	1.13	If you are warned that a new Portage version is available and that you should
195	nightmorph	1.110	update Portage, you should do it now using <c>emerge --oneshot portage</c>.
196	swift	1.13	</p>
197	swift	1.8
198			</body>
199			</subsection>
200	swift	1.72	<subsection>
201			<title>Choosing the Right Profile</title>
202			<body>
203
204			<p>
205			First, a small definition is in place.
206			</p>
207
208			<p>
209			A profile is a building block for any Gentoo system. Not only does it specify
210	nightmorph	1.112	default values for USE, CFLAGS and other important variables, it also locks
211	swift	1.72	the system to a certain range of package versions. This is all maintained by the
212			Gentoo developers.
213			</p>
214
215	nightmorph	1.106	<p>
216	nightmorph	1.102	Previously, such a profile was untouched by the users. However, there may be
217			certain situations in which you may decide a profile change is necessary.
218	swift	1.72	</p>
219
220			<p>
221	neysx	1.79	You can see what profile you are currently using with the following command:
222	swift	1.72	</p>
223
224			<pre caption="Verifying system profile">
225	nightmorph	1.112	# <i>eselect profile list</i>
226			Available profile symlink targets:
227			[1] <keyval id="profile"/> *
228			[2] <keyval id="profile"/>/desktop
229			[3] <keyval id="profile"/>/server
230	swift	1.72	</pre>
231
232			<p>
233	nightmorph	1.102	The default profile will provide you with a Linux 2.6-based system. This is the
234			recommended default, but you have the option of choosing another profile too.
235	neysx	1.80	</p>
236
237			<p>
238	nightmorph	1.99	There are also <c>desktop</c> and <c>server</c> subprofiles available for some
239	nightmorph	1.112	architectures. Running <c>eselect profile list</c> will show all available
240			profiles.
241	nightmorph	1.99	</p>
242
243			<p>
244	nightmorph	1.112	After viewing the available profiles for your architecture, you can use a
245			different one if you wish:
246	swift	1.72	</p>
247
248	nightmorph	1.106	<pre caption="Changing profiles">
249	nightmorph	1.112	# <i>eselect profile set 2</i>
250	swift	1.72	</pre>
251
252	nightmorph	1.106	<p test="func:keyval('arch')='AMD64'">
253			If you want to have a pure 64-bit environment, with no 32-bit applications or
254			libraries, you should use a non-multilib profile:
255	swift	1.72	</p>
256
257	nightmorph	1.106	<pre test="func:keyval('arch')='AMD64'" caption="Switching to a non-multilib profile">
258	nightmorph	1.112	# <i>eselect profile list</i>
259			Available profile symlink targets:
260			[1] <keyval id="profile"/> *
261			[2] <keyval id="profile"/>/desktop
262			[3] <keyval id="profile"/>/no-multilib
263			[4] <keyval id="profile"/>/server
264			<comment>(Choose the no-multilib profile)</comment>
265			# <i>eselect profile set 3</i>
266			<comment>(Verify the change)</comment>
267			# <i>eselect profile list</i>
268			Available profile symlink targets:
269			[1] <keyval id="profile"/>
270			[2] <keyval id="profile"/>/desktop
271			[3] <keyval id="profile"/>/no-multilib *
272			[4] <keyval id="profile"/>/server
273	swift	1.83	</pre>
274
275	nightmorph	1.111	<note>
276			The <c>developer</c> subprofile is specifically for Gentoo Linux development
277			tasks. It is <e>not</e> meant to help set up general development environments.
278			</note>
279
280	swift	1.72	</body>
281			</subsection>
282	swift	1.28	<subsection id="configure_USE">
283	swift	1.21	<title>Configuring the USE variable</title>
284			<body>
285
286			<p>
287			<c>USE</c> is one of the most powerful variables Gentoo provides to its users.
288			Several programs can be compiled with or without optional support for certain
289			items. For instance, some programs can be compiled with gtk-support, or with
290			qt-support. Others can be compiled with or without SSL support. Some programs
291			can even be compiled with framebuffer support (svgalib) instead of X11 support
292			(X-server).
293			</p>
294
295			<p>
296			Most distributions compile their packages with support for as much as possible,
297			increasing the size of the programs and startup time, not to mention an enormous
298	swift	1.24	amount of dependencies. With Gentoo you can define what options a package
299	swift	1.21	should be compiled with. This is where <c>USE</c> comes into play.
300			</p>
301
302			<p>
303			In the <c>USE</c> variable you define keywords which are mapped onto
304			compile-options. For instance, <e>ssl</e> will compile ssl-support in the
305	nightmorph	1.100	programs that support it. <e>-X</e> will remove X-server support (note the
306	nightmorph	1.115	minus sign in front). <e>gnome gtk -kde -qt4</e> will compile your
307	nightmorph	1.100	programs with gnome (and gtk) support, and not with kde (and qt) support,
308			making your system fully tweaked for GNOME.
309	swift	1.21	</p>
310
311			<p>
312	swift	1.68	The default <c>USE</c> settings are placed in the <path>make.defaults</path>
313			files of your profile. You will find <path>make.defaults</path> files in the
314			directory which <path>/etc/make.profile</path> points to and all parent
315			directories as well. The default <c>USE</c> setting is the sum of all <c>USE</c>
316			settings in all <path>make.defaults</path> files. What you place in
317	swift	1.21	<path>/etc/make.conf</path> is calculated against these defaults settings. If
318			you add something to the <c>USE</c> setting, it is added to the default list. If
319			you remove something from the <c>USE</c> setting (by placing a minus sign in
320			front of it) it is removed from the default list (if it was in the default list
321			at all). <e>Never</e> alter anything inside the <path>/etc/make.profile</path>
322			directory; it gets overwritten when you update Portage!
323			</p>
324
325			<p>
326			A full description on <c>USE</c> can be found in the second part of the Gentoo
327	neysx	1.52	Handbook, <uri link="?part=2&chap=2">USE flags</uri>. A full description on
328			the available USE flags can be found on your system in
329	swift	1.23	<path>/usr/portage/profiles/use.desc</path>.
330			</p>
331
332			<pre caption="Viewing available USE flags">
333			# <i>less /usr/portage/profiles/use.desc</i>
334	swift	1.45	<comment>(You can scroll using your arrow keys, exit by pressing 'q')</comment>
335	swift	1.23	</pre>
336
337			<p>
338			As an example we show a <c>USE</c> setting for a KDE-based system with DVD, ALSA
339			and CD Recording support:
340	swift	1.21	</p>
341
342			<pre caption="Opening /etc/make.conf">
343			# <i>nano -w /etc/make.conf</i>
344			</pre>
345
346			<pre caption="USE setting">
347	nightmorph	1.115	USE="-gtk -gnome qt4 kde dvd alsa cdr"
348	swift	1.21	</pre>
349
350	swift	1.69	</body>
351			</subsection>
352			<subsection>
353	nightmorph	1.106	<title>Optional: glibc Locales</title>
354	swift	1.69	<body>
355
356	dertobi123	1.53	<p>
357	rane	1.95	You will probably only use one or maybe two locales on your system. You can
358	rane	1.96	specify locales you will need in <path>/etc/locale.gen</path>.
359	dertobi123	1.53	</p>
360
361	rane	1.95	<pre caption="Opening /etc/locale.gen">
362			# <i>nano -w /etc/locale.gen</i>
363	dertobi123	1.53	</pre>
364
365			<p>
366	rane	1.95	The following locales are an example to get both English (United States) and
367			German (Germany) with the accompanying character formats (like UTF-8).
368	dertobi123	1.53	</p>
369
370	rane	1.95	<pre caption="Specify your locales">
371			en_US ISO-8859-1
372			en_US.UTF-8 UTF-8
373			de_DE ISO-8859-1
374			de_DE@euro ISO-8859-15
375	bennyc	1.60	</pre>
376
377	swift	1.67	<p>
378	rane	1.95	The next step is to run <c>locale-gen</c>. It will generate all the locales you
379			have specified in the <path>/etc/locale.gen</path> file.
380	swift	1.67	</p>
381
382	swift	1.1	<p>
383	swift	1.85	Now continue with <uri link="?part=1&chap=7">Configuring the Kernel</uri>.
384	swift	1.28	</p>
385
386			</body>
387			</subsection>
388			</section>
389	swift	1.3	</sections>