Linux Boot Process Explained 🐧💻

Almost every software engineer has used Linux before, but only a handful know how its Boot Process works :) Let's dive in. The diagram below shows the steps. Step 1 - When we turn on the power, BIOS (Basic Input/Output System) or UEFI (Unified Extensible Firmware Interface) firmware is loaded from non-volatile memory, and executes POST (Power On Self Test). Step 2 - BIOS/UEFI detects the devices connected to the system, including CPU, RAM, and storage. Step 3 - Choose a booting device to boot th

Linux Boot Process — Explained Step by Step 🐧⚙️ From pressing the power button to seeing the login screen, Linux follows a well-defined startup sequence. 1️⃣ Power On The system is powered on and control is handed to the firmware. 2️⃣ BIOS / UEFI Initial hardware checks (POST) are performed and bootable devices are detected. 3️⃣ Choose Boot Device The firmware selects the configured disk or device to boot from. 4️⃣ Boot Loader (GRUB) GRUB loads the Linux kernel and initial RAM filesystem, based