In this wikiHow, you will learn how to plan and develop an operating system in case you don't know how to code. Operating systems manage computer hardware and provide the resources that applications need to run. Writing an operating system from scratch requires a strong command of computer science, a programming language such as C or C ++, assembly, and code management practices.
Steps
Part 1 of 2: Learn the Basics
Step 1. Take a few basic computer science courses
Unlike development for the web, creating an operating system requires a solid understanding of algorithms, data structures, computer hardware, and resource management. Because people get degrees at this, you shouldn't expect to be able to write an entire operating system after reading an online tutorial. The Harvard Introduction to Computer Science course is available online at no cost through EDX.
Step 2. Learn a high-level programming language (eg C)
After you have a solid basic understanding of computer science, the next step is to master C or C ++. Like learning about computer science, mastering a language is not optional, since you won't be able to code an operating system if you can't write good applications.
In case you're new to C, check out Dartmouth's C Programming: Getting Started course, which is free through EDX. After completing that course, you can take the next one in the series: C Programming: Fundamentals of Language. Then, move on to subsequent courses (for example, Modular Programming and Memory Management and Pointers and Memory Management)
Step 3. Learn an assembly language
Assembly languages are low-level languages that are designed to communicate with different processors. The assembly differs for different types of processors (for example, x86 assembly language for Intel, AMD, VIA, and other processors), so you will need to learn the version for the type of processor you are coding for.
- By reading this open source book in its entirety, you can gain a solid enough understanding to build an operating system.
- The Art of Assembly Language is a highly recommended book on assembly that is available both online and offline.
- You should also do a lot of research on the type of processor or processors your operating system should run on. You can easily find manuals for processor architecture with a Google search ("Intel manuals", "ARM manuals", etc.).
Step 4. Complete an operating systems tutorial
The operating system tutorials guide you through the process of creating a basic operating system. This gets you used to the process and helps you determine if any parts are missing. After completing a tutorial or two, you are well on your way to creating your own operating system.
- Bare Bones is a tutorial that helps you write your first simple 32-bit kernel. After completing the tutorial, the next step is to use Meaty Skeleton to structure your own operating system.
- Linux from Scratch is an online book that guides you through creating your own Linux operating system.
- Operating Systems 0 to 1 is a free book on building various operating systems from start to finish.
Step 5. Determine your goals for the operating system
What do you want the operating system to do? How should it look? Do you really have to write an entire operating system or do you just want to create a certain look for your desktop? You should take all of these things into account before you start coding.
- Consider developing it with a team of other programmers. Having a team of developers working on the project will reduce development time significantly.
- Add your project goals, plans, and questions to your public repository so it's easy for others to help you.
Part 2 of 2: Developing Your Operating System
Step 1. Choose a development environment
This is the platform that you will use to code your new operating system. While it is a matter of personal preference, most people use either Windows or a type of UNIX. In case you are going to use Windows, it is recommended to install a UNIX environment (for example, Cygwin or MinGW). In general, you should be careful that the environment you use includes the following:
- GCC (the GNU compiler). In case you are going to use Windows, you can install it in Cygwin or MinGW.
- Binutils is a collection of tools used to manipulate object files. Again, if you are going to use Windows, you can install it in Cygwin.
- A good text editor. Vim and Emacs are commonly used in UNIX environments. Windows users can use Notepad or take a look at Notepad ++ for a multi-tabbed update.
- Perl or Python. One or both are recommended for string manipulation.
Step 2. Set up your version control system
Writing an operating system means that you are likely to create hundreds (or thousands!) Of lines of code. This can get confusing when working on reviews. Some options you can take a look at are CVS, Mercurial, and Subversion.
Step 3. Decide on a bootloader
In case you don't want to create one yourself, you can use an existing one, like Grand Unified Bootloader (GRUB). If you're feeling bold enough to code a bootloader, check out Rolling Your Own Bootloader on OSDev.org.
Step 4. Choose a core design
The kernel is the center of your system and provides an interface between the user and the computer hardware. There are monolithic nuclei and micronuclei. Monolithic cores implement all services in the kernel, while micro cores have a small kernel combined with user daemon implementation services. Monolithic cores are generally faster, but micro cores have better fault isolation and reliability.
Step 5. Start small
Start small, like displaying text and interrupts, before moving on to things like memory management and multitasking. You can also try making a simple 16-bit operating system instead of taking a big leap.
You won't have a complete system in two weeks. You start with a bootable operating system and then move on to cool stuff
Step 6. Test your new operating system with a virtual machine
Instead of restarting your computer every time you make changes or having to transfer files from your development computer to the test machine, use a virtual machine application. VMWare, as well as Bochs, is a common option that works with Windows and Linux. Review potential dead spots and other errors and repair as necessary.
Step 7. Launch a "release candidate"
You can do this by uploading the tested code to your public repository. This way, people can test your operating system and report any problems they find.
Step 8. Network with other operating system developers
There is a whole community of operating system developers congregating in various forums, including / r / osdev on Reddit and the Software Engineering Stack Exchange. After mastering the development of a basic operating system, read the existing publications to determine the kinds of things that come up during the development process.
Advice
- If you want your system to be viable, be careful to implement security features as your top priority.
- After finishing all the development, determine if you want to release the code in an open or registered way.
- Don't join to the OSDev.org forums and start asking obvious questions. This will only result in responses of "Read the manual". You should try to read Wikipedia and the manuals for the various tools you want to use.
- Do not start the project of an operating system to start learning to program. In case you do not already know C, C ++, Pascal or some other appropriate language backwards and forwards, including pointer manipulation, low-level bit manipulation, bit shifting, inline assembly language, etc., you will not be ready for operating system development.
- An operating system can also be easy to use. Be careful to add user-friendly elements, making them a fundamental part of your design.
- If you want an operating system to handle multiple processors, your memory manager must have "shutdown" mechanisms in place to prevent many processors from accessing a resource at the same time. The "locks" used for this will require the presence of a scheduler to ensure that only one processor accesses a critical resource at any time and that everyone else is kept waiting. However, the scheduler depends on the presence of a memory manager. This is a case of a deadlock dependency. There is no standard way to solve problems of this kind. As a programmer, you are expected to be skilled enough to deal with it in your own way.
- In case you do something wrong, like write random bytes to random input and output ports, the operating system will stop working and (in theory) you can burn the hardware.