The document discusses how to configure, compile, and install a custom Linux kernel, including downloading the source code, configuring options such as file systems and drivers, compiling and installing the kernel, and enabling features like SMP and SELinux support. Instructions are provided for both manual and DEB package installation of the custom kernel. Key steps involve obtaining the source, running make menuconfig to configure options, compiling with make, and installing the new kernel and initrd files.

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2. Drivers and the kernel UNIX system has three layers: The hardware The operating system kernel The user-level programs Kernel Kernel hides the hardware, provides a abstract, high-level programming interface Process Signal and semaphores Virtual memory The filesystem Interprocess communication Kernel contains device drivers that manage its interaction with specific pieces of hardware. Size of kernel

3. Why Configure the kernel Generic kernel Many device drivers Optional packages Tailor the kernel for your need Less memory Well-tuned configuration Add support for new types of device Some system is simple Some may need to several steps. Read this: Building the kernel is not difficult; its just difficult to fix when you break it. Get a good reference book for your OS

4. Kernel Source Repository http://kernel.org/ Is the place where you could get the kernel source Compile it according to your need

5. Packages required to start compilation apt-get install build-essential apt-get install bin86 kernel-package apt-get install module-init-tools initrd-tools apt-get install fakeroot apt-get install libncurses5-dev

6. Kernel Compilation Decide where to build your kernel Good place is $HOME Deciding on a kernel version For any kernel version x.y.z, * x - This is the major revision number * y - This is the minor revision number, where: Even numbers indicate "stable" kernel releases Odd numbers indicate "development" or "beta" kernel releases which may be less stable. * z - This is the patch level of the kernel

7. Downloading the maintainer-specific patch. Unpacking the kernel source bash$ cd $HOME bash$ tar zxvf linux-x.y.z.tar.gz bash$ cd linux-x.y.z bash$ zcat ../patch-x.y.z-vrs1.gz | patch -p1 For Cross compilation linux/README and linux/Documentation/arm/README before proceeding. Both these files provide further useful information which may be specific to your kernel version.

8. Configuration of the kernel build environment To use the default configuration present in kernel source bash$ make <machinename>_defconfig Copies the config of /linux-2.6-2.6.32/arch/x86/configs/i386_defconfig to .config In this case no need to run oldconfig To do manual configuration run the command $make menuconfig

9. Example for configuration Selecting necessary file systems File systems ---> Pseudo Filesystems ---> [*] /proc file system support [*] Virtual memory file system support (former shm fs) (Select one or more of the following options as needed by your system) Reiser, ext3, ext4, jfs, etc.,

10. Selecting PPPoE necessary drivers Device Drivers ---> Networking Support ---> <*> PPP (point-to-point protocol) support <*> PPP support for async serial ports <*> PPP support for sync tty ports

11. Activating SMP support Processor type and features ---> [*] Symmetric multi-processing support Like that we can do for the following options Activating USB Support for Input Devices Enabling PCMCIA support

12. Manual Installation Compiling the kernel Make Make modules_install Installing the kernel cp arch/i386/boot/bzImage /boot/vmlinuz Generate the initrd by using the tool mkinitrd mkinitramfs -k -o /boot/initrd.img-KVN KVN Edit the grub.cfg & boot the kernel

13. To get the kernel in DEB make-kpkg --initrd --revision=boss4.0 kernel_image kernel_headers --us –uc --append-to-version --revision

14. SELinux Configure Compile as like normal kernel Edit the /etc/init.d/rc Add the parameter selinux=1 to kernel line of grub