x86 Protected Mode: Global Descriptor Table and Segmentation
GDT and Segmentation Mechanism
At boot, x86 CPUs operate in real mode using segmented addressing: segment register × 16 + offset register yields physical addresses. This legacy approach lacks security features and modern multitasking support.
In protected mode, all 32 address lines become active, enabling 4GB physical addressing. Memory segment ...
Posted on Thu, 21 May 2026 21:06:38 +0000 by jb489