How do i start with OSdev

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Last updated: April 8, 2026

Quick Answer: To start with OS development, first learn C and assembly languages, as most operating systems are written in these. Set up a cross-compiler toolchain for your target architecture, such as x86-64, and use emulators like QEMU for testing. Begin with simple bootloaders and kernel basics, referencing resources like the OSDev Wiki, which has over 5,000 articles, and consider joining communities like the OSDev.org forums, established in 2002.

Key Facts

OS development typically requires knowledge of C and assembly languages, with many projects using C for over 90% of kernel code.
The OSDev Wiki, a key resource, contains over 5,000 articles and was started in the early 2000s.
Common target architectures include x86-64, ARM, and RISC-V, with x86-64 being the most popular for beginners.
Emulators like QEMU, first released in 2003, are essential for testing OS code without physical hardware.
The OSDev.org community, founded in 2002, has thousands of active members discussing development topics.

Overview

OS development, or OSdev, involves creating operating systems from scratch, a complex field rooted in computing history. The first operating systems, like GM-NAA I/O in 1956, were simple batch systems, evolving into modern OSes like Linux, released in 1991, and Windows NT in 1993. Today, OSdev is pursued by hobbyists, students, and professionals to understand low-level computing, with projects ranging from minimal kernels to full-featured systems. Key milestones include the development of Unix in 1969, which influenced many later OSes, and the rise of open-source movements in the 1990s, enabling collaborative development. Resources like the OSDev Wiki, started in the early 2000s, provide extensive documentation, covering topics from boot processes to memory management, making the field more accessible to newcomers.

How It Works

Starting with OSdev involves several technical steps. First, learn programming languages: C is used for most kernel code due to its efficiency and control, while assembly handles low-level tasks like bootloading and hardware interaction. Next, set up a development environment with a cross-compiler, such as GCC configured for a target like i686-elf, to compile code for the OS independently of the host system. Then, write a bootloader in assembly to initialize hardware and load the kernel; common boot protocols include BIOS (legacy) and UEFI (modern). The kernel, written in C, manages core functions like memory allocation, process scheduling, and device drivers. Testing is done using emulators like QEMU or Bochs, which simulate hardware without risk, and debugging tools like GDB help identify issues. Progress from basic tasks, such as printing text to the screen, to advanced features like multitasking and file systems.

Why It Matters

OS development matters because it deepens understanding of computer systems, enhancing skills in low-level programming, hardware interaction, and system design. It has real-world applications in embedded systems, where custom OSes power devices like routers and IoT gadgets, and in research for new computing paradigms, such as real-time or secure operating systems. For example, projects like seL4, a microkernel verified for security, demonstrate OSdev's impact on safety-critical industries. Learning OSdev also fosters innovation, as seen in hobbyist OSes that experiment with novel architectures or features. Ultimately, it contributes to the broader tech ecosystem by inspiring new tools and methodologies, and it prepares developers for careers in systems programming, kernel development, or cybersecurity, where such expertise is highly valued.