Chrooting
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 and /dev Filesystems
Mount the /proc filesystem on /mnt/gentoo/proc to
allow the installation to use the kernel-provided information within the
chrooted environment, and then mount-bind the /dev filesystem.
# mount -t proc none /mnt/gentoo/proc
# mount -o bind /dev /mnt/gentoo/dev
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
>> Regenerating /etc/ld.so.cache...
# source /etc/profile
# export PS1="(chroot) $PS1"
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 :-)
Configuring Portage
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're using a slow terminal like some framebuffers or a serial
console, you can add the --quiet option to speed up this process:)
# emerge --sync --quiet
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 do it now using emerge portage command.
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, there may be
situations in which you may decide a profile change is necessary.
Since 2006.0, there has been a re-shuffle regarding the profiles for MIPS
systems. These profiles set various options including USE flags, which affect
what patchsets are enabled with various system-critical packages (notably,
gcc and mips-sources).
Thus, care needs to be taken to ensure the correct profile is selected for your
system type. As of Gentoo/MIPS 2007.0, the profiles are:
| System |
Profile |
Userland |
Status/Notes |
Cobalt Qube/RaQ
default-linux/mips/2007.0/cobalt/o32
32-bit Linuxthreads
Recommended
"
default-linux/mips/2007.0/cobalt/o32/nptl
32-bit NPTL
In Testing (1)
| |
|
|
|
Generic Big Endian
Including SGI Indy, Indigo2 (R4x00), Challenge S and O2
default-linux/mips/2007.0/generic-be/o32
32-bit Linuxthreads
Recommended
"
default-linux/mips/2007.0/generic-be/o32/nptl
32-bit NPTL
In Testing (1)
"
default-linux/mips/2007.0/generic-be/n32
N32 Linuxthreads
Highly Experimental (2)
"
default-linux/mips/2007.0/generic-be/n32/nptl
N32 NPTL
Highly Experimental (1) (2)
"
default-linux/mips/2007.0/generic-be/n64
N64 Linuxthreads
Unsupported (3)
"
default-linux/mips/2007.0/generic-be/n64/nptl
N64 NPTL
Unsupported (1) (3)
| |
|
|
|
SGI Origin 200/2000
default-linux/mips/2007.0/ip27/o32
32-bit Linuxthreads
Recommended
"
default-linux/mips/2007.0/ip27/o32/nptl
32-bit NPTL
In Testing (1)
"
default-linux/mips/2007.0/ip27/n32
N32 Linuxthreads
Highly Experimental (2)
"
default-linux/mips/2007.0/ip27/n32/nptl
N32 NPTL
Highly Experimental (1) (2)
| |
|
|
|
SGI Indigo2 Impact R10000
default-linux/mips/2007.0/ip28/o32
32-bit Linuxthreads
Recommended
"
default-linux/mips/2007.0/ip28/o32/nptl
32-bit NPTL
In Testing (1)
"
default-linux/mips/2007.0/ip28/n32
N32 Linuxthreads
Highly Experimental (2)
"
default-linux/mips/2007.0/ip28/n32/nptl
N32 NPTL
Highly Experimental (1) (2)
| |
|
|
|
SGI Octane/Octane2
default-linux/mips/2007.0/ip30/o32
32-bit Linuxthreads
Recommended
"
default-linux/mips/2007.0/ip30/o32/nptl
32-bit NPTL
In Testing (1)
"
default-linux/mips/2007.0/ip30/n32
N32 Linuxthreads
Highly Experimental (2)
"
default-linux/mips/2007.0/ip30/n32/nptl
N32 NPTL
Highly Experimental (1) (2)
(1) NPTL is in-testing on MIPS at this stage, requiring gcc-4.1 and
glibc-2.4. It is believed that NPTL should be safe enough now for people
to use, and is planned to be the default in future releases. Brave users are
welcomed to try these profiles out and report back.
(2) n32 Userland is highly experimental, a lot of software has problems with
this ABI, and thus it is practically guaranteed that you will run into stability
problems at some point. Work is being done to improve the situation, however,
no support is offered if you use this profile, unless you're willing to help
fix problems by submitting patches.
(3) n64 Userland at present is completely unsupported on all systems. At this
time there are no stages available that support n64, and this isn't likely to
change in the near future.
You can see what profile you are currently using with the following command:
# ls -FGg /etc/make.profile
lrwxrwxrwx 1 48 Apr 8 18:51 /etc/make.profile -> ../usr/portage/profiles/default-linux/mips/2007.0/generic-be/o32/
Having looked through the profiles above, and decided which one is the most
appropriate, you need to adjust your make.profile symlink to
reflect this. By default, the profiles are in
/usr/portage/profiles, so if you've moved your portage tree
elsewhere (not recommended), adjust the commands below accordingly.
(Delete the old profile symlink)
# rm -f /etc/make.profile
(Create a new symlink pointing to your chosen profile )
(For example, this is what one would use on an Indy or O2.)
# ln -s /usr/portage/profiles/default-linux/mips/2007.0/generic-be/o32
A tip for those not familiar with the Bourne Again Shell... If you partially
type a filename or command, then hit the TAB key, it will automatically fill out
the command/filename until the last common character. E.g. typing
/usr/portage/profiles/def<TAB>, bash will automatically put
down default-. Pressing TAB a couple of more times will reveal the
possibilities, default-linux, default-darwin and
default-bsd. Give it a try, you'll find it very handy for navigating the
command line.
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 -qt3 -qt4 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 qt3 qt4 kde dvd alsa cdr"
Optional: GLIBC Locales
You will probably only use one or maybe two locales on your system. You can
specify locales you will need in /etc/locale.gen.
# nano -w /etc/locale.gen
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
The next step is to run locale-gen. It will generate all the locales you
have specified in the /etc/locale.gen file.
Now continue with Configuring the Kernel.