Building Linux Kernel

The process of building a Linux Kernel can be performed in several steps, but it may take time as per your hardware capabilities.

Step 1: Download the Source Code

Visit the Official Kernel Website and download the latest kernel source code. The downloaded files contains a compressed source code that you need to extract it.

Step 2: Extract the Source Code

After downloading, it is necessary to extract the source code. So, we will achieve this using tar command.

 tar xvf linux-6.13.tar.xz

If you don’t have tar, then download it using command:

 sudo pacman -S tar

Note: It is recommended to download the latest kernel source code and write it’s version correctly while using tar command.

Step 3: Install the Required Packages

Make sure you have additional packages to start compilation. To achieve this, you need to install the following packages:

 sudo pacman -S git fakeroot ncurses xz bc flex bison base-devel kmod cpio perl binutils util-linux jfsutils e2fsprogs xfsprogs squashfs-tools quota-tools

Step 4: Configure your kernel

  1. Navigate to linux-6.13 folder:
 cd linux-6.13
  1. Configue your kernel. It is recommended to use your current system’s configuration as a base. So write the following commands in order:
  • Use the following commad if you have zcat:
zcat /proc/config.gz > .config
  • Else you have to use following commands to simply copying config file:
 cp /proc/config.gz ./
 gunzip ./config.gz
 mv config .config

  1. Use the following commands to open a menu-driven interface to customize kernel options:

     make menuconfig
 make xconfig
 `make oldconfig`

  2. Make some changes in .config file:

    • Open it using command(you can use vim, kate, nano or any other text editor):
    sudo vim .config

    • Make following changes:

      search for CONFIG_EXT4_FS=m and set it to CONFIG_EXT4_FS=y.

Step 5: Start compilation

  1. Check for available processing CPU Cores using command:
 nproc

Note then n number of cores shown on the screen

  1. Initiate the compilation process:
 make -jn

Replace n with number of cores that you found using nproc command

And now your Kernel starts compiling

If any issue persists during or after running make -jn, then make a back up of .config file and run the command:

 make mrproper

make mrproper resets your entire broken tree back to the initial state.

Step 6: Install Modules

Insalling Kernel Modules are mandatory and they enhances the kernel’s capabilities, hardware support and other features while maintaining system stability and efficiency. You can install kernel modules using commad:

sudo make modules_install

Step 7: Install Kernel

The following are two different methods to install Kernel. Use the first method. If it doesn’t work, then use the second method carefully:

  1. Directly install through one command:
 sudo make install
  1. Use three commands properly and carefully:
  • Copy the Kernel Image:
 sudo cp arch/x86/boot/bzImage  /boot/vmlinuz-linux-custom
  • Copy the System.map file:
 sudo cp System.map  /boot/System.map-linux-custom
  • Copy the configuration file:
 sudo cp .config  /boot/config-linux-custom

Step 8: Update the Bootloader

Depending on your bootloader, you will need to add an entry for the new kernel. I am adding entry for GRUB as I uses it.

  1. Run the following command to know the UUID of your root partition (it will be in ext4 file system and have the mounting point as /) and copy it:
 lsblk -f
  1. Open the file using command:
 sudo nvim /etc/grub.d/40_custom
  1. Add the following content to the above mentioned file at the end:
  menuentry 'Custom Linux Kernel' {  
linux    /boot/vmlinuz-linux-custom  
root=UUID=paste-your-root-partition-uuid-here  
initrd /boot/initramfs-linux.img  
}

Step 9: Generate Initramfs

Generating Initramfs is necessary as you have compiled a new custom kernel, installed kernel modules, updated kernel configuration and updated bootloader. It is crucial for boot system. Use the command and make sure to input the correct version as I mentioned 6.13:

sudo mkinitcpio -k 6.13-custom -c /etc/mkinitcpio.conf -g /boot/initramfs-linux-custom.img

Step 10: Update GRUB configuration

Use the following command to update it as it will detect our new custom kernel:

 sudo grub-mkconfig -o /boot/grub/grub.cfg

That’s it. Configuration, you successfully build, compiled and installed your custom Kernel. Enjoy