CSCI 3310U Lecture Notes Flashcards

CSCI 3310U: Introduction

• Course code: CSCI 3310U

• Topic area: Systems Programming

• Course structure overview with various introduction sequences.

Today’s Learning Goals

• By the end of today’s lecture, students will be able to:

  • Understand what Systems Programming is.

  • Identify different types of System Calls.

  • Recognize the roles of Operating Systems.

  • Setup their working environment details.

Systems Programming

• Definition: Systems programming involves creating system calls to execute tasks and services offered by the operating systems.

• Interaction layers:

  • Operating Systems

  • Hardware

  • System Calls

  • Applications

  • User

Programs Execute in Two Modes

• Two primary execution modes for programs:

  User Mode

  • Definition: Limited access to memory, hardware, and other resources to ensure safety during program execution.

  • Characteristics:

    • Errors or crashes in user mode do not affect the entire system; considered "safe" for system stability.

    • Mostly used for running user applications and processes.

  Kernel Mode

  • Definition: Provides programs direct access to memory and hardware resources, allowing for more control and functionality.

  • Characteristics:

    • A crash in kernel mode has the potential to lead to a complete system failure.

    • Used for executing core system operations and managing underlying hardware resources.

System Calls

• Definition: A system call is a programmatic request for services or tasks from the operating system's kernel.

• Commonly coded in languages such as C, C++, and Rust.

• When programs in User Mode need resources, they call the operating system.

Types of System Calls

• Process Control: Manage processes (examples: end a process, load a process, execute, abort).

• File Manipulation: Interact with files (examples: create file, delete file, write to a file).

• Device Management: Handle devices (example: safely remove a device).

• Information Maintenance: Manage information retrieval (example: get current time or date).

• Communication: Facilitate message exchange between different processes.

Operating Systems

• Definition: Software that manages computer hardware and oversees processes and memory allocations.

• Examples of popular operating systems:

  • Mobile Operating Systems: Android, Apple iOS

  • Traditional Systems: Windows, Mac OS X, Linux

Operating Systems in Kernel Mode

• Run in Kernel mode (also called Supervisor/privileged mode).

• Provides direct access to hardware and can execute any instructions.

Operating Systems Structures

• Monolithic Operating System Structure: Traditional structure without modularity.

• Layered Operating Systems: Groups components by functionality into layers for better modularity and manageability.

• MicroKernel Structure: Minimizes the amount of services within the kernel; promotes scalability, extensibility, and portability.

• Loadable Kernel Modules: Modern OS might integrate loadable kernel modules, allowing components to communicate via known interfaces and load as necessary.

Summary of Learning Goals

• Recap of today's objectives:

  • Understanding Systems Programming.

  • Exploring System Calls.

  • Reviewing Operating Systems.

  • Setting up environment details.