nuta/operating-system-in-1000-lines
Operating System In 1000 Lines
This project is an educational operating system kernel designed to demonstrate the fundamental architectural principles of memory paging and process management. It is implemented as a minimal kernel that serves as a practical reference for building a functioning system from the ground up.
The implementation features a preemptive multitasking kernel that switches execution contexts between threads to share a single CPU. It includes an x86 virtual memory manager that uses paging to map virtual addresses to physical memory and isolate processes.
The system covers low-level hardware interfacing through disk drivers for raw read and write operations, as well as privilege-level mode separation to restrict user-mode execution. Interaction is handled via a text-based command line shell, and the project includes specialized techniques for low-level kernel debugging.
Features
- Kernel Development - Provides a minimal kernel implementation to demonstrate core architectural principles like paging and scheduling.
- x86 Kernel Implementations - Implements a minimal x86 kernel demonstrating core principles such as memory paging and interrupt handling.
- Monolithic Kernels - Implements a monolithic kernel where all core operating system services run in the privileged kernel space.
- Educational Kernel Projects - Serves as an educational project demonstrating the implementation of threading, scheduling, and memory protection.
- Context Switching Implementations - Provides the capability to swap execution states between tasks to allow shared CPU access.
- Educational Kernel Thread Implementations - Implements a multitasking system with kernel threads for educational demonstration of process switching.
- Kernel Shells - Ships a text-based command line shell for user interaction and kernel command execution.
- Preemptive Multitasking Kernels - Implements a kernel that switches process contexts between threads to enable shared CPU access.
- Privilege Level Management - Manages processor execution levels to isolate user-mode applications from privileged kernel operations.
- Context Switching Mechanisms - Implements CPU execution state swapping to enable preemptive multitasking across multiple threads.
- User-Mode Execution Environments - Implements a restricted privilege level for applications to prevent interference with kernel operations.
- Virtual Memory Management - Provides a system for managing virtual memory and mapping virtual addresses to physical memory locations.
- Command Line Shells - Implements a custom command-line interpreter for interacting with the underlying kernel.
- Raw Disk Drivers - Implements a hardware interface for raw read and write operations on physical storage devices.
- Disk Block I/O - Implements low-level synchronous data transfers between memory buffers and disk hardware controllers.
- Disk Device Drivers - Provides low-level drivers for raw read and write operations on physical storage hardware.
- Hardware Interfacing and Drivers - Implements drivers that facilitate direct communication between the kernel and physical disk hardware.
- Kernel Component Debugging - Provides diagnostic workflows for troubleshooting driver-level code and kernel-mode memory management.
- File System I/O - Provides the fundamental kernel capability to perform read and write operations on a structured file system.
- Low-Level Debuggers - Implements low-level debugging tools to identify errors in boot sequences and memory paging.
- Raw Block Device Writing - Implements the ability to write binary data directly to physical disk blocks, bypassing the file system.
