But how do it do?

Understanding how operating systems route hardware and software interrupts

This question tests your knowledge of a foundational OS mechanism: how the kernel establishes a communication channel between hardware events and the code that handles them. When the system boots, the OS must configure the CPU to know where to jump when an interrupt or exception occurs—whether it comes from a hardware device, a timer, or a user-space program making a system call.

To answer this, you need to identify the specific kernel data structure responsible for storing and managing these handler addresses. Understanding this structure is essential for grasping how modern operating systems achieve privilege separation, handle asynchronous events, and switch between user and kernel modes. Questions like this appear in OS interviews because they separate candidates who have read about interrupts from those who understand the mechanics of how they actually work.

• Privilege levels and mode switching
• Hardware interrupts vs. software exceptions
• The boot sequence and early kernel initialization