Chrooting
Optional: Selecting Mirrors
In order to download source code quickly it is recommended to select a fast
mirror. Portage will look in your make.conf file for the
GENTOO_MIRRORS variable and use the mirrors listed therein. You can surf to
our mirror list 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 mirrorselect which
provides you with a nice interface to select the mirrors you want.
# mirrorselect -i -o >> /mnt/gentoo/etc/make.conf
Do not select any IPv6 mirrors. Our stages currently do not support IPv6.
A second important setting is the SYNC setting in make.conf. 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, mirrorselect can ease that operation for you:
# mirrorselect -i -r -o >> /mnt/gentoo/etc/make.conf
After running mirrorselect it is adviseable to double-check the settings
in /mnt/gentoo/etc/make.conf !
Copy DNS Info
One thing still remains to be done before we enter the new environment and that
is copying over the DNS information in /etc/resolv.conf. You need
to do this to ensure that networking still works even after entering the new
environment. /etc/resolv.conf contains the nameservers for your
network.
(The "-L" option is needed to make sure we don't copy a symbolic link)
# cp -L /etc/resolv.conf /mnt/gentoo/etc/resolv.conf
Mounting the proc Filesystem
Mount the /proc filesystem on /mnt/gentoo/proc to
allow the installation to use the kernel-provided information even within the
chrooted environment.
# mount -t proc none /mnt/gentoo/proc
Entering the new Environment
Now that all partitions are initialized and the base environment
installed, it is time to enter our new installation environment by
chrooting 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).
This chrooting is done in three steps. First we will change the root
from / (on the installation medium) to /mnt/gentoo
(on your partitions) using chroot. Then we will create a new environment
using env-update, which essentially creates environment variables.
Finally, we load those variables into memory using source.
# chroot /mnt/gentoo /bin/bash
# env-update
* Caching service dependencies...
# source /etc/profile
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 :-)
Updating the Portage tree
You should now update your Portage tree to the latest version. emerge
--sync does this for you.
# emerge --sync
If you are behind a firewall that blocks rsync traffic, you can use
emerge-webrsync which will download and install a portage snapshot for
you.
If you are warned that a new Portage version is available and that you should
update Portage, you should ignore it. Portage will be updated for you later
on during the installation.
Choosing the Right Profile
First, a small definition is in place.
A profile is a building block for any Gentoo system. Not only does it specify
default values for CHOST, 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.
Previously, such a profile was barely touched by the user. However, recently,
x86, hppa and alpha users can choose between two profiles, one for a 2.4 kernel
and one for a 2.6 kernel. This requirement has been imposed to improve the
integration of the 2.6 kernels.
You can see what profile you are currently using by issuing the following
command:
# ls -l /etc/make.profile
lrwxrwxrwx 1 root root 48 Mar 7 11:55 /etc/make.profile ->
../usr/portage/profiles/default-linux/x86/2005.0
If you are using one of the aforementioned three architectures, you will see an
additional profile in the one listed by the make.profile symlink:
# ls -F /etc/make.profile/
2.4/ packages parent virtuals
As you can see, in the above example there is a 2.4 subdirectory. This means
that the current profile uses the 2.6 kernel; if you want a 2.4-based system,
you need to relink your make.profile symlink:
# ln -snf /usr/portage/profiles/default-linux/x86/2005.0/2.4 /etc/make.profile
Configuring the USE variable
USE 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).
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 USE comes into play.
In the USE variable you define keywords which are mapped onto
compile-options. For instance, ssl will compile ssl-support in the
programs that support it. -X will remove X-server support (note the minus
sign in front). gnome gtk -kde -qt will compile your programs with gnome
(and gtk) support, and not with kde (and qt) support, making your system fully
tweaked for GNOME.
The default USE settings are placed in the make.defaults
files of your profile. You will find make.defaults files in the
directory which /etc/make.profile points to and all parent
directories as well. The default USE setting is the sum of all USE
settings in all make.defaults files. What you place in
/etc/make.conf is calculated against these defaults settings. If
you add something to the USE setting, it is added to the default list. If
you remove something from the USE 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). Never alter anything inside the /etc/make.profile
directory; it gets overwritten when you update Portage!
A full description on USE can be found in the second part of the Gentoo
Handbook, USE flags. A full description on
the available USE flags can be found on your system in
/usr/portage/profiles/use.desc.
# less /usr/portage/profiles/use.desc
(You can scroll using your arrow keys, exit by pressing 'q')
As an example we show a USE setting for a KDE-based system with DVD, ALSA
and CD Recording support:
# nano -w /etc/make.conf
USE="-gtk -gnome qt kde dvd alsa cdr"
Optional: GLIBC Locales
You will probably only use one or maybe two locales on your system. Up until now
after compiling glibc a full set of all available locales will be
created. As of now you can activate the userlocales USE flag and specify
only the locales you will need in /etc/locales.build. Only do this
if you know what locales to choose. This will not work for the bootstrapping,
but when you recompile glibc afterwards it will.
# mkdir /etc/portage
# echo "sys-libs/glibc userlocales" >> /etc/portage/package.use
Now specify the locales you want to be able to use:
# nano -w /etc/locales.build
The following locales are an example to get both English (United States) and
German (Germany) with the accompanying character formats (like UTF-8).
en_US/ISO-8859-1
en_US.UTF-8/UTF-8
de_DE/ISO-8859-1
de_DE@euro/ISO-8859-15
Progressing from Stage1 to Stage2
Introduction to Bootstrapping
So, you want to compile everything from scratch? Okay then :-)
In this step, we will bootstrap your Gentoo system. This takes a
long time, but the result is a system that has been optimized from the
ground up for your specific machine and needs.
Bootstrapping means building the GNU C Library, GNU Compiler
Collection and several other key system programs.
Before starting the bootstrap, you might want to download all necessary
sourcecode first. If you do not want to do this, continue
with Bootstrapping the System.
Optional: Downloading the Sources First
If you haven't copied over all source code before, then the bootstrap
script will download all necessary files. If you want to
download the source code first and later bootstrap the system (for instance
because you don't want to have your internet connection open during the
compilation) use the -f option of the bootstrap script, which will
fetch (hence the letter f) all source code for you.
# cd /usr/portage
# scripts/bootstrap.sh -f
Bootstrapping the System
Okay then, take your keyboard and punch in the next commands to start
the bootstrap. Then go amuse yourself with something else because this step
takes quite some time to finish.
# cd /usr/portage
# scripts/bootstrap.sh
Now continue with the next step, Progressing from Stage2
to Stage3.
Progressing from Stage2 to Stage3
Introduction
If you are reading this section, then you have a bootstrapped system
(either because you bootstrapped it previously, or you are using a
stage2). Then it is now time to build all system packages.
All system packages? No, not really. In this step, you will build
the system packages of which there are no alternatives to use.
Some system packages have several alternatives (such as system loggers)
and as Gentoo is all about choices, we don't want to force one upon you.
Optional: Viewing what will be done
If you want to know what packages will be installed, execute emerge
--pretend --emptytree system. This will list all packages that will be
built. As this list is pretty big, you should also use a pager like
less or more to go up and down the list.
# emerge --pretend --emptytree system | less
Note that, if you haven't touched the default CFLAGS/CXXFLAGS setting, using
emerge --pretend --newuse system is sufficient: it will rebuild the
applications that are affected by a change in USE flags (compared to the USE
flag we used while building the stage2). If you didn't touch
the USE flag either, why are you running a stage2 installation then?
Optional: Downloading the Sources
If you want emerge to download the sources before you continue
(for instance because you don't want the internet connection to be left
open while you are building all packages) you can use the --fetchonly
option of emerge which will fetch all sources for you.
# emerge --fetchonly --emptytree system
Building the System
To start building the system, execute emerge --emptytree system. Then
go do something to keep your mind busy, because this step takes a long time to
complete.
# emerge --emptytree system
Again, if you haven't touched the default CFLAGS and CXXFLAGS setting, using
--newuse is sufficient.
You can for now safely ignore any warnings about updated configuration files
(and running etc-update). When your Gentoo system is fully installed and
booted, do read our documentation on Configuration File Protection.
When the build process has completed, continue with Configuring the Kernel.