The /boot directory in Linux

Meet the four files that bring the Operating System to life

Every Linux system has a boot directory, with all the needed files for the boot process. This directory is mounted directly on the root file system and is called /boot.

On my Linux system (Ubuntu 22.10), when I go into the /boot directory and call the ls utility, I get the following result:

$ cd /boot
$ ls
config-5.19.0-26-generic      memtest86+.elf
config-5.19.0-28-generic      memtest86+_multiboot.bin
efi                           System.map-5.19.0-26-generic
grub                          System.map-5.19.0-28-generic
initrd.img                    vmlinuz
initrd.img-5.19.0-26-generic  vmlinuz-5.19.0-26-generic
initrd.img-5.19.0-28-generic  vmlinuz-5.19.0-28-generic
initrd.img.old                vmlinuz.old

Out of all of these files, there are four that stand out:

1. The Configuration file
2. The System Map file
3. The Linux Kernel file
4. The Initial RAM Disk file

I’d like to dive into what these files represent, and for that, it’s important to notice that all of them have a suffix. The suffix represents the Linux Kernel version that they target.