Crate polished_interrupts 

Interrupt Handling Library

This crate provides low-level interrupt management for x86_64 systems, including the setup of the Interrupt Descriptor Table (IDT), CPU exception handlers, and hardware interrupt handlers. It is designed for use in OS kernels or bootloaders running in a no_std environment.

How Interrupts Work

Interrupts are signals that temporarily halt the normal execution flow of the CPU to handle urgent events, such as hardware requests (keyboard, timer, etc.) or software exceptions (division by zero, page faults, etc.). When an interrupt occurs, the CPU saves its current state and jumps to a handler function specified in the Interrupt Descriptor Table (IDT). After the handler completes, the CPU resumes execution where it left off.

Types of Interrupts

• CPU Exceptions: Triggered by error conditions in program execution (e.g., invalid opcode, page fault).
• Hardware Interrupts (IRQs): Triggered by external devices (e.g., keyboard, timer, disk controller).
• Software Interrupts: Triggered by instructions like int n (e.g., for system calls).

Where Interrupts Are Used

• Exception Handling: To catch and handle errors such as division by zero or invalid memory access.
• Device Communication: To respond to hardware events (e.g., keyboard presses, timer ticks).
• Preemptive Multitasking: To switch between tasks on timer interrupts.
• System Calls: Some OSes use software interrupts for syscalls, but this library does not use the legacy int 0x80 or similar interrupt-based syscalls.

System Call Implementation Options

There are two main approaches for implementing syscalls on x86_64:

1. Software Interrupts: Using instructions like int 0x80 (legacy, slower, not used here).
2. Fast Syscall Instructions: Using syscall/sysret (preferred for modern OSes, not implemented in this library).

This library focuses on exception and hardware interrupt handling, not syscall dispatch.

Modules

• cpu_exceptions: Sets up handlers for CPU exceptions (e.g., page fault, double fault).
• hardware_interrupts: Sets up handlers for hardware IRQs (e.g., timer, keyboard).

Usage

Call init_idt() early in kernel initialization to set up the IDT and enable interrupt handling.

Modules

cpu_exceptions

CPU exception handler setup (e.g., page fault, double fault).

hardware_interrupts

Hardware interrupt handler setup (e.g., timer, keyboard).

Functions

init_idt

Initialize the Interrupt Descriptor Table (IDT) and load it into the CPU.