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The Boot Process — Theory

Understand what actually happens from power-on to your OS. Learn about the BIOS/UEFI, reset vector, memory map, system clock, secure boot, initramfs, and chainloading.

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~360 Minutes 8 Challenges

how computer boot process works

About this subtrack

Boot Process Theory documents reset vectors, BIOS maps, and modern secure boot context before you write a single sector.

The Boot Process — Theory

About this subtrack

Tasks (8)

Document the Full Power-On Sequence: From PSU to OS

Use QEMU Monitor to Inspect BIOS Entry State

Understand the Reset Vector: Why CPU Starts at 0xFFFFFFF0

Read the BIOS Memory Map: A20 Line and Reserved Regions

Explore the CMOS and RTC: Read System Clock with BIOS INT 0x1A

Understand UEFI Secure Boot and Chain of Trust

Understand the Initial RAM Filesystem (initramfs)

Understand Bootloader Chainloading