Introduction

Objectives

1. Define operating systems.
2. Discuss, at a high level, what operating systems do.

Notes

• This is chapter 1 of the book.
• The first real sentences of the book

  An operating system is the software that manages a computer's hardware. It also provides a basis for application programs and acts as an intermediary between the computer user and the computer hardware.

• Operating systems, like most other aspects of computing are a human creation
  • There have been many different ideas on how to do this.
  • They have evolved over time,
    • In response to hardware changes
    • In response to usage changes
    • And other pressures
• And different operating systems have different goals.
• So there is no single "right" way to do things.
• Like many other high level cs courses, OS is a sub-topic of computer science that can lead to a PhD.
• Quick exercise: Name all of the operating systems you know, their goal and the hardware they run on.
• What do operating systems do?
  • Look at the figure from page 4
    • Hardware
    • OS
    • Applications
    • User
  • What are each of these?
  • I would debate this somewhat, as the user interacts with the OS?
  • The authors state the the OS provides the environment where other software can do useful work.
• The user thinks
  • They "own" all of the hardware
    • This might be true on your laptop or cell phone.
    • But it is not in a shared environment.
  • The OS is there to provide
    • maximum utilization of this hardware
    • and make it easy to use.
  • Interaction ranges from
    • a cell phone, where the user is the entire raison d'être.
    • To an embedded device such as the computer in your car, where the user is far removed from the os/hardware.
• The system (hardware)
  • The system consists of:
    • a small number of processors (CPU/Cores)
    • a limited amount of memory
    • a set of special devices
    • ...
  • Who should be allowed to use these, for how long and in what capacity?
  • What happens when there is a conflict? What about an error?
  • In the human world, we have laws, protocols, customs and such that control the use/access/control of physical and not so physical resources.
• The diversity of uses/hardware makes it hard to precisely define what an operating system is.
  • A Keurig probably is not a computer, just preprogrammed logic.
  • An Arduino nano
    • probably doesn't run an OS, just a single application.
      • But it looks like someone is trying to develop ArduinoOS.
      • Mostly focused on tasks, no file system, no shell, no external devices
      • This might not work on the nano, I didn't mess with it.
    • There appear to be others under development.
  • Modern cars might run Android Automotive on their infotainment system.
    • My truck apparently runs Chevy Infotainment 2 system.
    • But actual truck might be controlled by a Chevy proprietary ECM/ECU.
    • Take a look at this video.
      • They connected via an exposed network port to the infotainment system.
      • They then bridged to the car's internal network
      • And issued commands on this network.
• So the book resorts to a laundry list of items
  • The kernel is the "single program" that runs.
    • We will see that this is a bad definition
  • It has a number of supporting systems programs that interact with the OS to perform OS like tasks
  • And application programs or applications/apps that provide actions the users want to perform.
• We will probably spend the rest of the semester on this definition.