Windows Kernel – Introduction
The Windows kernel is the core of the Microsoft Windows operating system. It provides low‑level services such as process and thread management, memory handling, hardware abstraction, and security. Understanding the kernel is essential for driver developers, system programmers, and anyone interested in the inner workings of Windows.
Overview
The kernel is divided into two main components:
- Executive: High‑level services (I/O manager, object manager, security subsystem, etc.).
- Kernel‑mode core (NTOSKRNL): Scheduler, memory manager, interrupt handling, and low‑level hardware interaction.
Architecture
Windows follows a layered architecture that separates user mode from kernel mode, providing stability and security.
+---------------------------------------------------+
| User‑mode (Applications) |
+---------------------------------------------------+
| Win32 Subsystem (CSRSS) |
+---------------------------------------------------+
| Executive (Sub‑systems) |
| +----------------+ +---------------------------+ |
| | I/O Manager | | Object Manager | |
| | Memory Manager | | Security Subsystem | |
| +----------------+ +---------------------------+ |
+---------------------------------------------------+
| Kernel‑mode Core (NTOSKRNL) |
+---------------------------------------------------+
| Hardware Abstraction Layer (HAL) |
+---------------------------------------------------+Key Components
- Scheduler: Manages CPU time for threads.
- Memory Manager: Handles virtual memory, paging, and address translation.
- I/O Manager: Provides a uniform interface for device I/O.
- Object Manager: Implements kernel objects (files, events, mutexes, etc.).
- Security Subsystem: Enforces access control and integrity.
- HAL (Hardware Abstraction Layer): Isolates the kernel from hardware specifics.
Development Resources
For driver and kernel development, Microsoft provides the following tools and documentation:
- Windows Driver Kit (WDK)
- Debugging Tools for Windows
- Kernel-Mode Development Guide
- Win32 API Reference