<<< Rings of protection, four levels of security     Index     Flat vs. Segmented Memory Model >>>

32. Three types of segment descriptor tables

  • 1. Global descriptor table GDT

    • Only one in the system

    • Contains OS code and data

    • Available to all tasks

  • 2. Local descriptor table LDT

    • Several LDTs may exist for a program.

    • Contains descriptors of a program

  • Segment descriptor format:

      Segment descriptor format

<<< Rings of protection, four levels of security     Index     Flat vs. Segmented Memory Model >>>