Tuesday, October 11, 2005

Mini HOWTO #3: compiling and installing a custom Linux kernel

  • Go to the /usr/src/linux directory, where linux is a link to the appropriate kernel version (e.g. /usr/src/linux-2.4)
  • Edit the EXTRAVERSION line of /usr/src/linux/Makefile. Change the definition for EXTRAVERSION=versionnumber to something that uniquely identifies your kernel, for example EXTRAVERSION=RHcustom.
  • Run make mrproper to ensure your source files are in a consistent and clean state.
  • Save a copy of the old configuration file /usr/src/linux/.config to a secure location.
  • If you want to reuse an old configuration file as a starting point, copy it to /usr/src/.config and run make oldconfig
  • Customize the kernel. Use make config for a text-based interface, make menuconfig for a curses-based interface or make xconfig for an X-based interface. Select all desired/needed options.
  • Run make dep to set up all dependencies correctly.
  • Run make bzImage to create a gzip-compressed kernel image file. This will compile the kernel, which can be a lengthy process depending on your hardware.
  • Run make modules to build the kernel modules.
  • Copy kernel image file to /boot directory: cp /usr/src/linux/arch/i386/boot/bzImage /boot/vmlinuz-2.4.19-RHcustom
  • Run make modules_install to install the kernel modules into /lib/modules/2.4.19-RHcustom.
  • Build support for an initial RAM disk (initrd) by running: mkinitrd /boot/initrd-2.4.19-RHcustom.img 2.4.19-RHcustom
  • Copy the new kernel’s symbol table and configuration file to the /boot partition: cp /usr/src/linux/System.map /boot/System.map-2.4.19-RHcustom; cp /usr/src/linux/.config /boot/config-2.4.19-RHcustom
  • Update the boot manager configuration files.
    • For GRUB, update /etc/grub.conf with a section for the new kernel.
    • For LILO, update /etc/lilo.conf with a section for the new kernel and then run lilo –v.

No comments: