HOWTO Gentoo 2004.2 for linux 2.6 and NPTL

From Gentoo Linux Wiki

[edit] Intro

This guide is intended to help those wanting to build a Gentoo system using NPTL and a 2.6 kernel.

[edit] Installing Gentoo Linux

With your LiveCD burned to a disk and your Bios configured to boot from CD go head and restart your PC. Refer to the Gentoo Handbook for more information about obtaining and burning a Gentoo 2004.2 LiveCD.

[edit] Boot Option

Now boot from the LiveCD and type smp at the boot prompt.[Only applies to OLD Live CDs]

boot: smp

smp is a 2.6 kernel that will allow proc to be populated with information from a running 2.6 kernel rather than a 2.4 kernel like gentoo. This is necessary in order for glibc to be compiled with NPTL support. Refer to the Gentoo Handbook for options passable to the kernel during boot.

[edit] Hard Drive Preparation

Preparing your hard drive for Gentoo Linux: In this guide i will use fdisk to partition my hard drive.

fdisk /dev/hda

You will need atleast a / (root) and swap partition. Create filesystems and mount partitions.

mke2fs /dev/hda1
mke2fs -j /dev/hda5
mkswap /dev/hda6
swapon /dev/hda6
mount /dev/hda5 /mnt/gentoo
mkdir /mnt/gentoo/boot
mount /dev/hda1 /mnt/gentoo/boot

[edit] Time Check

Check to ensure your PC has the correct time.

date

[edit] Installing the Gentoo installation files

Change to the /mnt/gentoo directory.

cd /mnt/gentoo

Use links to download a stage1 tarball from a gentoo mirror.

links http://www.gentoo.org/main/en/mirrors.xml

• You must have networking configured and enabled.

After downloading the stage1 tarball extract it.

/bin/tar -xvjpf stage?-*.tar.bz2 && rm stage?-*.tar.bz2

[edit] Configuring make.conf

Open make.conf for editing.

Code: 
CFLAGS="-O2 -march=athlon-xp -pipe" 
CHOST="i686-pc-linux-gnu"
CXXFLAGS="${CFLAGS}" 
USE="nptl nptlonly"

[edit] Optional

Selecting mirrors.

mirrorselect -a -s4 -o | grep 'GENTOO_MIRRORS=' >> /mnt/gentoo/etc/make.conf

This command will populate GENTOO_MIRRORS in /etc/make.conf.

Note: I prefer using mirrorselect -i -o >> /mnt/gentoo/etc/make.conf. In my opinion choosing the mirror(s) closest to you manually will bring better results than a small, one time test done by mirrorselect -a -s4 -o

Before we chroot into the new Gentoo environment you may want to run passwd to change the root password so it is possible to log into another vt.

[edit] Chrooting

• Copy resolv.conf so networking continues to function after chroot'ing.

cp -L /etc/resolv.conf /mnt/gentoo/etc/resolv.conf

• Mount /proc

mount -t proc none /mnt/gentoo/proc

• OPTIONAL: Changing the root password

If you want to change virtual terminals (Alt-F1 through Alt-F6) to do other cmd-line tasks while installing gentoo, you need to do this command in order to be able to login. This only changes the root password for the LiveCD environment.

passwd

• Chroot'ing into the new Gentoo environment.

chroot /mnt/gentoo /bin/bash
env-update && source /etc/profile

[edit] Updating Portage

Sync the portage tree.

emerge sync

Note: To avoid killing rsync servers and avoid getting stuck forever on a slow rsync server it might be easier and faster if you download a snapshot of the portage tree and then sync it.

emerge-webrsync && emerge sync

[edit] Stage1 to Stage2

• Merging the Linux 2.6 headers

emerge --nodeps --oneshot linux26-headers

• Bootstrapping the system: (Stage1 to Stage2)

cd /usr/portage
scripts/bootstrap.sh && env-update && source /etc/profile

• bootstrap-cascade.sh is nolonger a valid option
• If you experience problems with installing documentation after compiling glibc try to do that:

echo ">=sys-libs/glibc-2.3.4.20041102-r1" >> /etc/portage/package.mask; scripts/bootstrap.sh && 
env-update && source /etc/profile

• To check if NPTL support was compiled into glibc type:

/lib/libc.so.6

• This holds true for x86 users however if you're an ~x86 user you will not see this properly

"You should see 'Native POSIX Threads' in the output." the NPTL libraries are moved to a new dir refer to the ebuild to see the command you need to run.

[edit] Stage2 to Stage3

Building the system: (Stage2 to Stage3)

emerge system && env-update && source /etc/profile && etc-update

[edit] Configuring the Kernel

Configure timezone.

ln -sf /usr/share/zoneinfo/UTC /etc/localtime

Remember to use your own timezone!

Selecting and configuring a kernel:

emerge gentoo-sources

Refer to the Gentoo Handbook for other 2.6 kernels available and howto configure and install them.

[edit] Optional

• Installing udev.

emerge udev

Don't forget to take devfs support out of the kernel configuration, since udev does the job.

• Installing hotplug.

emerge hotplug && rc-update add hotplug boot

• Installing alsa.

emerge alsa-utils && rc-update add alsasound boot && nano -w /etc/modules.d/alsa && modules-update

Refer to the ALSA Handbook for further information on configuring a sound card.

If your soundcard is directly supported by the kernel, just emerge alsa-utils.

[edit] Configuring your System:

Refer to the Gentoo Handbook on editing fstab, network configuration files, and rc.conf.

[edit] Installing Necessary System Tools

• Install a system logger.

emerge metalog && rc-update add metalog default

• Install a cron daemon.

emerge vixie-cron && rc-update add vixie-cron default

[edit] Optional

• Installing gentoolkit.

emerge gentoolkit

Contains tools for working with portage.

• Installing ufed.

emerge ufed

An application to simplify selecting/deselecting USE variables.

[edit] Configuring the Bootloader:

Installing grub.

emerge grub

Refer to the Gentoo Handbook on configuring grub.

• Setting a root password.

passwd

• Creating a user.

useradd username -m -G users,wheel,audio,tty -s /bin/bash
passwd username

You can now safely exit and restart your PC and boot into your new Gentoo installation.

exit
cd /
umount /mnt/gentoo/boot
umount /mnt/gentoo/proc
umount /mnt/gentoo
reboot

[edit] Getting NPTL to work on already running systems

This is already covered in HOWTO Migrate to NPTL, however, for completeness, we will also discuss it in this article.

So, begin by editing your /etc/make.conf

• Add the following two USE Flags:

nptl nptlonly

If you use not-so-recent binary only commercial applications (for example Matlab 6.5) that don't work with NPTL, re-emerge glibc without the nptlonly USE flag, so you will be able to use linuxthreads with

export LD_ASSUME_KERNEL=2.4.1
$COMMAND

• Remove your current headers.

emerge -C linux-headers

• Grab the latest 2.6 kernel (NPTL support any version of the 2.6 kernel, gentoo-sources are used as an example).

emerge gentoo-sources

• Emerge the linux26 headers.

emerge linux26-headers

• Now begin recompiling your system to work with NPTL.

emerge glibc

Restart, and you're done.

[edit] Credits

Original Forums Post by Snooper