How To Compile A Kernel - The Debian (Sarge) Way

Submitted by () () on Tue, 2006-12-05 16:30. :: |

 

补充一句，文中建议将源码在 /usr/src 里解包并建立 linux 连结

引用:

tar xjf linux-2.6.18.3.tar.bz2
ln -s linux-2.6.18.3 linux
cd /usr/src/linux

这是不正确的，这方式是以前 2.4.x 内核的方式，在 2.6 的内核并不需要，用了反而会另某些软件编译出错！

 

 

How To Compile A Kernel - The Debian (Sarge) Way

Version 1.0
Author: Falko Timme
Last edited 11/28/2006

原文:

 

Each distribution has some specific tools to build a custom kernel from the sources. This article is about compiling a kernel on Debian Sarge systems. It describes how to build a custom kernel using the latest unmodified kernel sources from () so that you are independent from the kernels supplied by your distribution. It also shows how to patch the kernel sources if you need features that are not in there.

I have tested this on Debian Sarge in VMware Server.

I want to say first that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take. I do not issue any guarantee that this will work for you!

 

1 Preliminary Note

The goal of this tutorial is to build a kernel .deb package that can be installed on the system, and that you can share with others and install on other Debian Sarge systems which is a big advantage compared to the "traditional" way where you don't end up with a .deb package.

2 Install Required Packages For Kernel Compilation

First we update our package database:

apt-get update

Then we install all needed packages like this:

apt-get install kernel-package libncurses5-dev fakeroot wget bzip2 build-essential udev

Please note that we have just installed udev which replaces the old (deprecated) devfs in new kernels. The default Debian Sarge kernel (2.6.8) still uses devfs which isn't available anymore in new kernels.

3 Download The Kernel Sources

Next we download our desired kernel to /usr/src. Go to and select the kernel you want to install, e.g. linux-2.6.18.3.tar.bz2 (you can find all 2.6 kernels here: ). Then you can download it to /usr/src like this:

cd /usr/src
wget

Then we unpack the kernel sources and create a symlink linux to the kernel sources directory:

tar xjf linux-2.6.18.3.tar.bz2
ln -s linux-2.6.18.3 linux
cd /usr/src/linux

 

4 Apply Patches To The Kernel Sources (Optional)

Sometimes you need drivers for hardware that isn't supported by the new kernel by default, or you need support for virtualization techniques or some other bleeding-edge technology that hasn't made it to the kernel yet. In all these cases you have to patch the kernel sources (provided there is a patch available...).

Now let's assume you have downloaded the needed patch (I call it patch.bz2 in this example) to /usr/src. This is how you apply it to your kernel sources (you must still be in the /usr/src/linux directory):

bzip2 -dc /usr/src/patch.bz2 | patch -p1 --dry-run
bzip2 -dc /usr/src/patch.bz2 | patch -p1

The first command is just a test, it does nothing to your sources. If it doesn't show errors, you can run the second command which actually applies the patch. Don't do it if the first command shows errors!

If your patches are compressed with gzip (.gz) instead of bzip2 (.bz2), then you patch your kernel as follows:

gunzip -c /usr/src/patch.gz | patch -p1 --dry-run
gunzip -c /usr/src/patch.gz | patch -p1

You can also apply kernel prepatches to your kernel sources. For example, if you need a feature that is available only in kernel 2.6.19-rc6, but the full sources haven't been released yet for this kernel. Instead, a patch-2.6.19-rc6.bz2 is available. You can apply that patch to the 2.6.18 kernel sources, but not to kernel 2.6.18.1 or 2.6.18.2 or 2.6.18.3, etc. This is explained on :

Prepatches are the equivalent to alpha releases for Linux; they live in the testing directories in the archives. They should be applied using the patch(1) utility to the source code of the previous full release with a 3-part version number (for example, the 2.6.12-rc4 prepatch should be applied to the 2.6.11 kernel sources, not, for example, 2.6.11.10.)

So if you want to compile a 2.6.19-rc6 kernel, you must download the 2.6.18 kernel sources () in step 3 instead of kernel 2.6.18.3!

This is how you apply the 2.6.19-rc6 patch to kernel 2.6.18:

cd /usr/src
wget
cd /usr/src/linux
bzip2 -dc /usr/src/patch-2.6.19-rc6.bz2 | patch -p1 --dry-run
bzip2 -dc /usr/src/patch-2.6.19-rc6.bz2 | patch -p1

 

5 Configure The Kernel

It's a good idea to use the configuration of your current working kernel as a basis for your new kernel. Therefore we copy the existing configuration to /usr/src/linux:

make clean && make mrproper
cp /boot/config-`uname -r` ./.config

Then we run

make menuconfig

which brings up the kernel configuration menu. Go to Load an Alternate Configuration File and choose .config (which contains the configuration of your current working kernel) as the configuration file:

 

 

Then browse through the kernel configuration menu and make your choices. Make sure you specify a kernel version identification string under General Setup ---> () Local version - append to kernel release. I use -default1 so our kernel .deb package will be named linux-2.6.18.3-default1_2.6.18.3-default1_i386.deb. Please make sure that the string contains a digit (e.g. 1, 2, ...) because otherwise the kernel build process will result in an error.

Please note: After you have installed linux-2.6.18.3-default1_2.6.18.3-default1_i386.deb and decide to compile another 2.6.18.3 kernel .deb package, it is important to use a different version string, e.g. -default2, -default3, etc., because otherwise you can't install your new kernel because dpkg complains that linux-2.6.18.3-default1_2.6.18.3-default1_i386.deb is already installed!

Next make sure you enable the Fusion MPT device drivers under Device Drivers --> Fusion MPT device support. I don't know if this is necessary on all platforms; at least it is on mine (Debian Sarge on a VMware Server) because otherwise you'll get this error message when you boot your new kernel:

/bin/cat: /sys/block/sda/dev: No such file or directory

which results in a kernel panic.

Then browse through the rest of the kernel configuration menu and make your choices. When you are finished and select Exit, answer the following question (Do you wish to save your new kernel configuration?) with Yes:

 

 

6 Build The Kernel

To build the kernel, execute these two commands:

make-kpkg clean
fakeroot make deb-pkg

Now be patient, the kernel compilation can take some hours, depending on your kernel configuration and your processor speed.

 

7 Install The New Kernel

After the successful kernel build, you can find your kernel .deb package in the /usr/src directory.

cd /usr/src
ls -l

On my test system it was called linux-2.6.18.3-default1_2.6.18.3-default1_i386.deb. I install it like this:

dpkg -i linux-2.6.18.3-default1_2.6.18.3-default1_i386.deb

(You can now even transfer the .deb file to other Debian Sarge systems and install it there exactly the same way, which means you don't have to compile the kernel there again.)

 

8 Create A Ramdisk

Now we must create a ramdisk for our new kernel. Normally we do this with mkinitrd, but our new kernel uses udev instead of devfs, and you'll most likely get this error message with an mkinitrd generated ramdisk during boot-up:

mount: unknown filesystem type 'devfs'

which might lead to a kernel panic.

The new way of creating ramdisks is with mkinitrd.yaird. has a yaird package for Debian Sarge. Before we can install it, we must install two prerequisites:

apt-get install libhtml-template-perl libparse-recdescent-perl

Then we install yaird like this:

cd /tmp
wget
dpkg -i yaird_0.0.12-8bpo1_i386.deb

(The original yaird package was located in , but was removed in the meantime, so I've made the package available under .)

Before we can create the new ramdisk, we must edit the configuration file of our new kernel which you can find in the /boot directory (run

ls -l /boot

to find out). In this tutorial it's called /boot/config-2.6.18.3-default1, and in that file we must comment out the line CONFIG_DEFCONFIG_LIST (towards the beginning of the file) because otherwise mkinitrd.yaird will throw an error like this at us:

yaird error: bad value in /boot/config-2.6.18.3-default1: CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config" (fatal)

So we do this:

vi /boot/config-2.6.18.3-default1

[...]
# CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
[...]

Now we can finally create our ramdisk like this:

mkinitrd.yaird -o /boot/initrd.img-2.6.18.3-default1 2.6.18.3-default1

 

9 Configure The GRUB Boot Loader

Now we must configure our GRUB boot loader so that our new kernels gets booted when we restart the system. This is very easy, just run

update-grub

You can check /boot/grub/menu.lst to see if your new kernel has been added:

vi /boot/grub/menu.lst

It should look like this now (you should find two stanzas for your new kernel at the top of the kernel stnazas list):

# menu.lst - See: grub(8), info grub, update-grub(8)
#            grub-install(8), grub-floppy(8),
#            grub-md5-crypt, /usr/share/doc/grub
#            and /usr/share/doc/grub-doc/.

## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
default         0

## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout         5

# Pretty colours
color cyan/blue white/blue

## password ['--md5'] passwd
# If used in the first section of a menu file, disable all interactive editing
# control (menu entry editor and command-line)  and entries protected by the
# command 'lock'
# e.g. password topsecret
#      password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
# password topsecret

#
# examples
#
# title         Windows 95/98/NT/2000
# root          (hd0,0)
# makeactive
# chainloader   +1
#
# title         Linux
# root          (hd0,1)
# kernel        /vmlinuz root=/dev/hda2 ro
#

#
# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST

### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below

## DO NOT UNCOMMENT THEM, Just edit them to your needs

## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specifiv kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
# kopt=root=/dev/sda1 ro

## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd0,0)

## should update-grub create alternative automagic boot options
## e.g. alternative=true
##      alternative=false
# alternative=true

## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
##      lockalternative=false
# lockalternative=false

## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
##      altoptions=(recovery mode) single
# altoptions=(recovery mode) single

## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
##      howmany=7
# howmany=all

## should update-grub create memtest86 boot option
## e.g. memtest86=true
##      memtest86=false
# memtest86=true

## ## End Default Options ##

title           Debian GNU/Linux, kernel 2.6.18.3-default1
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.18.3-default1 root=/dev/sda1 ro
initrd          /boot/initrd.img-2.6.18.3-default1
savedefault
boot

title           Debian GNU/Linux, kernel 2.6.18.3-default1 (recovery mode)
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.18.3-default1 root=/dev/sda1 ro single
initrd          /boot/initrd.img-2.6.18.3-default1
savedefault
boot

title           Debian GNU/Linux, kernel 2.6.8-2-386
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.8-2-386 root=/dev/sda1 ro
initrd          /boot/initrd.img-2.6.8-2-386
savedefault
boot

title           Debian GNU/Linux, kernel 2.6.8-2-386 (recovery mode)
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.8-2-386 root=/dev/sda1 ro single
initrd          /boot/initrd.img-2.6.8-2-386
savedefault
boot

### END DEBIAN AUTOMAGIC KERNELS LIST

 

10 Reboot

Now reboot the system:

shutdown -r now

If everything goes well, it should come up with the new kernel. You can check if it's really using your new kernel by running

uname -r

This should display something like

2.6.18.3-default1

If the system doesn't start, restart it, and when you come to the GRUB boot loader menu, select your old kernel and start the system:

 You can now try again to compile a working kernel. Don't forget to remove the two stanzas of the not-working kernel from /boot/grub/menu.lst.