computer science operating system

CS Primer - Operating Systems

Intro to Operating Systems

• Chapter two of OSTEP
• Fetch --> Decode --> Execute
  • Basics of the von Neumann architecture
• In charge of making sure the system operates correctly and efficiently
• Virtual machine
  • Takes a physical resource (processor, memory, disk, etc.) and transforms it into an easy-to-use virtual form
• Sys calls
  • OS APIs
• A resource manager
• Policies determine which programs should run
• "You should be using Emacs. If you are using vi, there is probably something wrong with you. If you are using something that is not a real code editor, that is even worse." 💀
• Protocols for protecting writes
  • Journaling
  • Copy-on-write
• Goals
  • Abstractions
  • Performance
  • Protection between apps
  • Reliability
  • Energy efficiency
  • Security
• System call vs procedure call
  • System call transfers control into the OS while raising the hardware privilege level
• User apps run in "user mode"
  • Hardware restricts what apps can do