Linux - Boot Architecture
IEN-001 - Understanding the Linux Boot Process: From Power-On to User Space
Introduction Imagine arriving at the office on a Monday morning and discovering that one of your...
IEN-002 - Stage 1 — Firmware Initialization (BIOS & UEFI)
Before Linux, before GRUB, and even before the operating system exists, the computer must first p...
IEN-003 - Stage 2 — The Bootloader (GRUB)
At the end of the firmware stage, the computer has completed its hardware initialization and iden...
IEN-004 - Stage 3 — Linux Kernel Initialization
At the end of the previous stage, GRUB has successfully loaded two critical files into memory: ...
IEN-005 - Stage 4 — initrd / initramfs: Preparing the System to Mount the Root Filesystem
By the end of the previous stage, the Linux kernel is fully operational. It has: initialized ...
IEN-006 - Stage 5 — Mounting the Root Filesystem
After the initrd (or initramfs) has completed its work, the system finally reaches one of the mos...
IEN-007 - Stage 6 — PID 1: The Beginning of User Space
At the end of the previous stage, the Linux kernel has successfully mounted the real root filesys...
IEN-008 - Stage 7 — System Service Initialization
At the end of the previous stage, the Linux kernel has successfully transferred control to PID 1....
IEN-009 - Stage 8 — User Login: Entering User Space
At this point, the Linux system has completed nearly all of its startup sequence. The firmware i...