0.1 — Physical Machine

In one line: before you defend a computer, you should know what one actually is — down to the box and the wires.

Most security people skip hardware. They learn it the hard way years later — when they hit a buffer overflow that doesn’t make sense, or a BIOS rootkit they can’t see, or a side-channel attack on a CPU register they didn’t know existed.

We won’t skip it. This chapter walks you through the machine like a curious mechanic walks around a car for the first time.

The tone for this chapter is simple: touch the real thing first, name the technical thing second, then ask what an attacker would do with it. That is the Feynman-style ladder for hardware security.

By the end you’ll be able to:

• Open up a PC tower and name every part on the motherboard
• Explain what happens between pressing the power button and seeing the login screen
• Point at any component and say what an attacker would do with it

Lessons

1. 0.1.1 What a computer actually is
2. 0.1.2 Bits and bytes — how machines count
3. 0.1.3 Hexadecimal and why hackers love it
4. 0.1.4 Tour of a PC tower
5. 0.1.5 The CPU — the worker
6. 0.1.6 How a CPU runs one instruction
7. 0.1.7 Registers and cache
8. 0.1.8 RAM — the desk
9. 0.1.9 Storage — HDD vs SSD vs NVMe
10. 0.1.10 Motherboard, chipset, buses
11. 0.1.11 GPU — the artist and the parallel calculator
12. 0.1.12 Power, cooling, the case
13. O — keyboard, mouse, USB, monitor
14. UEFI — the pre-OS whisper
15. 0.1.15 The full boot sequence
16. 🧪 0.1.L1 Lab — open the box

Image credit

• Computer_from_inside_018.jpg — Kallerna, public domain.