Liangxu Linux

Sep 14, 2025 · Fundamentals

Why Is Address 0 Considered Illegal in C/C++? A Deep Dive into Memory Layout and Zero‑Address Usage

The article explains the common misconception that address 0 is always illegal, clarifies why operating systems reserve it, and shows how bare‑metal and embedded development can freely use address 0 with concrete assembly examples and C/C++ representations.