Idiots Guide to 2.6.x kernel compiles

Idiots Guide to 2.6.x kernel compiles
--------------------------------------

I am writting this to give a general walkthrough of how
to compile and install the new 2.6 series kernel. Below are
three major selling points of why to upgrade from 2.4
- Bootup time is so much faster
- Alsa support built right into the kernel (sound)
- Your system almost feels like it has a faster CPU in it

Ok enough with the good points. Lets get down to the install.
All the shell commands will start with a #. These should be
run in either the console or a console window (xterm)

1) Change directories to the standard place for kernel installs. Since
a lot of 3rd party applications look for the kernel source in
/usr/src lets compile in that directory.
# cd /usr/src

2) Now lets download the newest kernel. At the time of writting this
2.6.0-test11 is the lastest. This seems to change every 2-3 weeks.
I like to use ncftp but you are free to use any ftp client.
# ncftp ftp.kernel.org
At the ftp prompt send the following commands
ftp> cd pub/linux/kernel/v2.6
ftp> get linux-2.6.0-test11.tar.bz2
wait.. wait.. and wair

3) Once it is down downloading. Exit out of the ftp client and lets
un package our new kernel
# tar jxfv linux-2.6.0-test11.tar.bz2

4) You will notice it gets un-packaged in /usr/src/linux-2.6.
We want to also put it in /usr/src/linux. So lets create a
symlink
# ln -sf linux-2.6.0-test11 linux

5) Now that we have a symlink created Go into that directory and lets
configure our new kernel
# cd linux
There are two options to config the kernel. Open a ncurses window,
which you can do in a console window or if you are using X you can
open a nice GUI window.
# make menuconfig (for the ncurses based)
or
# make xconfig (for the X based)

6) This is the part where you have to know something about your system.
Most system, this default config will work just fine. Chances are
You will need to install your network driver and sound driver. I am
going to show you where those are, the rest is up to you to figure
out

7) Follow this path to your network driver.
Device Drivers->Networking Support->Ethernet (10 or 100Mbit)
In there you will see a list of chipsets. Select the one that meets
your needs.
* = means compiled into the kernel
M = means as a module
I'd reocmmend compiling them into the kernel

8) Lets do the same for your soundcard. From the root menu
Device Drivers->Sound->Advanced Linux Sound Architecture->PCI devices

9) Save your kernel. In the xconfig hit the disk icon of file->save.
In the menuconfig just keep selecting exit until you are prompted to
save.

10) Lets compile your kernel!
# make

11) If you don't see any errors, lets install it
# make install

12) Your kernel is installed, but we have to do some moving around
of the kernel files first and then edit the boot loader. So lets
get the files in the right place. make install copies the files
to your root partition (/) so lets move them out of there into the
/boot directory
# cd /
# mv vmlinux /boot/vmlinuz-2.6.0-test11
# mv System.map /boot/System.map-2.6.0-test11
I like to change the name so I can keep my old kernels labeled. Its
always a good idea to keep older kernels, just in case a compile
doesn't load for you. That way you can always go back to the old
kernel and get into your OS.

13) We need to change the symlink for the old System.map to point
to the new one.
# ln -sf /boot/System.map-2.6.0-test11 /boot/System.map

14) Now we need to make a kernel image. This is because Redhat (Fedora)
used partition labels. If you do now use a kernel ramdisk image
then your kernel will not load. You can get around this by replacing
all occurances of parition labels with their partition, but that is a
pain so lets make a ramdisk image Also the ext3 is built as a module
so your OS will not load if you do not make an ramdisk image
# mkinitrd /boot/initrd-2.6.0-test11.img 2.6.0-test11

15) Now lets edit our bootloader.
I like vi, but feel free to use any text editor you like
# vi /etc/lilo.conf
that is for lilo
# vi /boot/grub/grub/conf
that is grub.
Now in there your last line will be something like this


LILO
-----
image=/boot/vmlinuz-2.4.22-1.2115.nptl
label=2.4.22-1.2115.n
initrd=/boot/initrd-2.4.22-1.2115.nptl.img
read-only
append="root=LABEL=/"
Grub
----
title Fedora Core (2.4.22-1.2115.nptl)
root (hd0,0)
kernel /vmlinuz-2.4.22-1.2115.nptl ro root=LABEL=/
initrd /initrd-2.4.22-1.2115.nptl.img


That is the standard kernel for fedora core1. So what we do is copy
that whole section and then paste it right below it. Now that we
have two copies of it we need to edit it to look like this

LILO
------
image=/boot/vmlinuz-2.6.0-test11
label=2.4.0-test11
initrd=/boot/initrd-2.6.0-test11.img
read-only
append="root=LABEL=/"

Grub
------
title 2.6.0-test11
root (hd0,0)
kernel /vmlinuz-2.6.0-test11 ro root=LABEL=/
initrd /initrd-2.6.0-test11.img


16) If you run grub you can just reboot and you just see the new
kernel in your grub menu. If you use lilo then run the following
command
# lilo
You should see the 2.6.0-test11 listed and then you are good
to go ahead and reboot.