Operating Systems

By the end, you can

• Explain the two roles of an operating system and where it sits relative to apps and hardware.
• Describe the difference between kernel mode and user mode, and explain how a system call crosses that boundary.
• Trace the steps the kernel loop performs on every incoming request.
• Explain how virtual memory and page tables provide process isolation.
• Describe round-robin scheduling, including the roles of the quantum, timer interrupt, and context switch.
• Trace the path from a filename to the actual disk bytes through the directory and inode.
• Explain what a device driver does and why it allows the same app code to run on different hardware.
• Describe how the kernel boundary enables security permission prompts.
• Explain how the OS handles resource limits gracefully.