Part 2: Single-/MultiTask OS Background

The Previous Part

The previous part introduced the processor's role in the system. In addition, it provided an introduction to the evolution of the register set, the instruction set and exceptions. It consist of the following chapter:

• “Overview of the Processor Role” on page 9.

This Part

This part introduces the goals of single-task and multi-task OSs and consists of the following chapters:

• “Single-Task OS and Application” on page 23.

• “Definition of Multitasking” on page 27.

• “Multitasking Problems” on page 31.

The Next Part

The next part provides a detailed description of the 386 processor, the baseline ancestor of the IA32 processor family. It consists of the following chapters:

• “386 Real Mode Operation” on page 39.

• “Protected Mode Introduction” on page 103.

• “Intro to Segmentation in Protected Mode” on page 109.

• “Code Segments” on page 133.

• “Data and Stack Segments” on page 157.

• “Creating a Task” on page 171.

• “Mechanics of a Task Switch” on page 191.

• “386 Demand Mode Paging” on page 209.

• “The Flat Model” on page 247.

• “Interrupts and Exceptions” on page 251.

• “Virtual 8086 Mode” on page 329.

• “The Debug Registers” on page 375.