Summary

This chapter began with an overview of device drivers, including details on the instruction sequences used by driver code to read from and write to a simple I/O device: the PC parallel port. We continued with a discussion of the legacy BIOS and the newer UEFI, which provide the code that first executes on PC power-up, performs device testing and initialization, and initiates loading of the operating system. We saw how the trusted boot process can ensure that only authorized and unmodified code can be permitted to execute during system startup.

We continued with a description of some of the fundamental elements of operating systems, including processes, threads, and the scheduler. Various scheduling algorithms used in past computers and the systems of today were introduced. We examined the output of tools available in Linux and Windows that present information about running processes.

The chapter concluded with a discussion of multiprocessing and its performance impact...