Compiling kernel 2.6.21

From Linuxintro

This is an example how to compile a Linux kernel. It has been tested for SUSE Linux 10.2 and kernel 2.6.21, but should work same or similar for every combination.

Check prerequesites

  • Make sure you have a compiler installed
yast -i gcc 

Get the code

  • Download the kernel from
  • unpack the kernel
bunzip linux-2.6.21.tar.bz2
  • unpack the kernel for the second time
tar xvf linux-2.6.21.tar

Build it

  • configure the kernel
cd linux-2.6.21
make oldconfig
  • answer some un-understandable questions

The sense of the step make oldconfig is to tell the kernel its configuration, e.g. which parts should be built as a module, which parts should not be built at all and the name of your special build. oldconfig takes over the settings from the running kernel that you can check with zcat /proc/config.gz. The settings for the new kernel are stored in the file .config. E.g. a line CONFIG_LOCALVERSION="-thorsten" in .config would tell kernel 2.6.27 to call himself 2.6.27-thorsten.

  • compile the kernel, note: on a two-CPU VMWare virtual machine with 2.4 GHz, this lasted 19m28.605s
make -j4
  • compile the drivers
make -j4 modules

Install it

  • install the drivers
make modules_install
  • install the kernel
cp arch/x86_64/boot/bzImage /boot/vmlinuz-2.6.21

This will install the kernel for the x86_64 architecture.

  • prepare the initial ramdisk
cp /boot

This will build an initial ramdisk for all kernels contained in /boot.

  • add an entry to the bootloader. Let's take grub's /boot/grub/menu.lst:
title 2.6.21-selfcompiled
   root (hd0,0)
   kernel /boot/vmlinuz-2.6.21 root=/dev/sda1
   initrd /boot/initrd-2.6.21

Newer kernels

x86_64 and x86_32 were merged into the x86 folder.