Minimal filesystem

In order to work, a Linux system needs at least a few applications
An init application, which is the first user space application started by the kernel after mounting the root filesystem
- The kernel tries to run /sbin/init, /bin/init, /etc/init and /bin/sh.
- In the case of an initramfs, it will only look for /init. Another path can be supplied by the rdinit kernel argument.
- If none of them are found, the kernel panics and the boot process is stopped.
- The init application is responsible for starting all other user space applications and services
A shell, to implement scripts, automate tasks, and allow a user to interact with the system
Basic Unix applications, to copy files, move files, list files (commands like mv, cp, mkdir, cat, etc.)
These basic components have to be integrated into the root filesystem to make it usable

Overall booting process