OS Motivation

1 Introduction

1.1 Learning Objectives

• Discuss role of OSs to control computers
  • Performance aspects
  • Ownership and control
• Discuss role of licenses to control software

(See here for an introduction to learning objectives; note the role of verbs to specify the target level of knowledge/skill)

1.2 Performance Aspects

• OS manages computer’s resources: CPU, memory, I/O
• OS understanding helps to identify and reason about resource bottlenecks.
  • Improve design, analysis, and implementation of information systems.
  • E.g., why is my computer/application slow? How to improve that?
• (Above are “traditional” topics for OS courses; this presentation takes a different direction.)

1.3 Whom do Computers Obey?

• Recall (long-term) goal of CSOS

  

  “ Notebook ” under CC0; from Pixabay

  • “Play and experiment with and control any computer, at any level of interest”

• In CS part, you learned how to build a computer.
  • How does that feel?

• In OS part, we investigate Operating Systems (OSs) to control computers.

  

  “ Search ” under CC0; from Pixabay

  • OS controls what is executing when.
  • Who controls the OS?
  • Who controls the computer, then?

1.4 Computers

1.5 Enlightenment

Enlightenment is man’s emergence from his self-incurred immaturity.

• Your computer does whatever it is programmed to do.
• You can succumb to somebody else’s programming.
• Or emerge.

2 Choices and Consequences

2.1 Impact of Choices

• Economic and ecological/social impact

  

  “ Man with megaphone ” under CC0; from Pixabay

  • What do you buy/use/create?
    • What do you advertise?
    • What do you impose on others?
• Economic impact
  • Should be obvious

• Ecological/social impact

  

  “ Image ” under CC0; from Pixabay

  • If you use some social/communication service, you increase its appeal and value
    • Network effects, feedback loops, externalities
  • If you choose communication under surveillance, you impose surveillance on your family, friends, colleagues …

2.2 Rationale

• If you want to own a device containing a computer (“smart” anything, recall slide on computers), you need to control its software.
  • (Including firmware and underlying hardware)
    • (Topic in its own right, maybe for term’s final lecture)

• Otherwise,

  

  “ Control ” under CC0; from Pixabay

  • device may work against you, see IoT Hall of Shame,
    • e.g., smartphones and diesel engines,
  • device may stop working any time,
    • e.g., bricked smart home entertainment device (2017) and hub (2016), Orwell books removed from Kindle (2009),
  • device may stop receiving (security) updates any time.

3 Software

3.1 Free Software

• Free Software = Free/Libre and Open Source Software (FLOSS)

  

  “ Photo of Richard Stallman ” by Victor Powell under CC BY-SA 3.0; from Wikimedia

  • Term coined by Richard Stallman, Free Software Foundation
  • “Free” as in free speech or freedom, not free beer
• Four freedoms
  1. Run software (also changed versions)
  2. Study software
  3. Redistribute copies
  4. Distribute modified versions

3.2 Free vs Open Source

• Whether software is free (libre) or open source (or both, FOSS, FLOSS) or something else, depends on the license
  • 1986: Free software defined
    • See GNU’s Bulletin 1 for origin
  • 1998: Open Source Software (OSS) defined
  • See Comparison of free and open-source software licenses
    • Well-known FLOSS licenses include Apache License, GNU Public License, Eclipse Public License, Mozilla Public License

• The distinction is mostly philosophical, sometimes religious
  • I prefer the term “free software” because it emphasizes freedom

3.3 GNU/Linux

• Linux is a free OS kernel

  

  “ Tux, the Linux mascot ” under CC0; from Wikimedia

• GNU/Linux is a family of free OSs

  • Naming controversy
  • I encourage you to try out GNU/Linux, which is
    • free software,
    • the major OS for cloud infrastructures,
    • the server OS in lots of project seminars.
  • Upcoming assignments are based on GNU/Linux
    • Several GNU/Linux distributions can be started as live systems from CD/DVD or USB stick without changing your current installation
      • Help on getting started
    • Exercise session on June 6, 4pm in our PC Pool for live tests and questions!

4 Conclusions

4.1 Summary

• Free software is a necessary precondition to control computers
  • … and everything embedding a computer

    • … which is a lot in times of ubiquitous computing and IoT!

      

      “ Internet of Things ” by Wilgengebroed on Flickr under CC BY 2.0; from Wikimedia

• Do you care?

License Information

This presentation is part of an Open Educational Resource (OER) course on Operating Systems. Source code and source files are available under free licenses on GitLab.

Except where otherwise noted, this work, “OS Motivation”, is © 2018 by Jens Lechtenbörger, published under the Creative Commons license CC BY-SA 4.0.

No warranties are given. The license may not give you all of the permissions necessary for your intended use.

In particular, trademark rights are not licensed under this license. Thus, rights concerning third party logos (e.g., on the title slide) and other (trade-) marks (e.g., “Creative Commons” itself) remain with their respective holders.