Some Preliminary Insights on the Linux Kernel Source

Many people have heard of Linux, as it’s very famous in the open-source community. However, not everyone knows how to configure, compile, and install/upgrade the Linux kernel. This article provides a brief introduction to the Linux kernel source.

Motivation

There may be several different motivations for learning the Linux kernel source. I was interested in the Linux kernel source because I wanted to understand how the Linux kernel works. I was curious about how the kernel manages hardware resources, schedules processes, and handles system calls. I also wanted to learn how to configure, compile, and install/upgrade the kernel. I think these are the basic skills that every Linux user should have.

Obtaining Linux Kernel Source

The Linux kernel source can be obtained from the official Linux kernel website: http://www.kernel.org/. The kernel source is released as a compressed tarball file, you may extract that and modify any parts as needed.

Compiling Linux Kernel

For the ubuntu/debian system, you can install the tools for compiling the Linux kernel by running the following command:

(root)# apt install build-essential libncurses5-dev

Then, you can compile the Linux kernel by following these steps:

• Extract the kernel source tarball file

  $ tar -xvf linux-${version}.tar.bz2
  $ cd linux-${version}

• Configure the kernel

  # Text-based interface
  $ make config
  
  # or, Menu-based interface (semi-graphical interface)
  $ make menuconfig
  
  # or, Graphical interface (requires X Window libraries)
  $ make xconfig

• Compile the kernel

  # Confirm dependencies
  $ make dep
  
  # Generate the kernel image
  $ make bzImage
  
  # Generate the kernel modules
  $ make modules

• Install/Update

  # install the modules
  (root)# make modules_install
  
  # install the kernel
  (root)# make install

• Update the bootloader configuration file (e.g., GRUB)

  (root)# update-initramfs -c -k ${version}
  (root)# update-grub

Appendix

When configuring the kernel, there are many options to choose from, such as CPU-related options, kernel management methods, memory usage modes, plug-and-play support, and network protocol components. It is recommended to understand the meaning of each option before making changes; otherwise, you may compile a kernel that differs from your expectations. For more information on these options, visit http://www.tldp.org/.