How to write a simple operating system in assembly language

How to write a simple operating system in Assembler? User Name Password Programming This forum is for all programming questions. The question does not have to be directly related to Linux and any language is fair game. Notices Welcome to LinuxQuestions.

How to write a simple operating system in assembly language

RodolfoNeres via Wikimedia Commons Writing assembly language is something best left for the experts. To write code that runs directly on your microprocessor you need to know how memory segmentation works, what the intended use of each register is, how codes executes in real and protected modes and much, much more.

And, of course, modern compilers will usually produce faster, more optimized code than you ever could, without making any mistakes. Someday you might need to debug code without having the original source. But most importantly, learning about assembly language can be a lot of fun.

Usually Reading Assembly Language Is No Fun At All Unfortunately, most of us only see assembly language after something has gone wrong, terribly wrong, when we encounter something like this: This is what a segmentation fault looks like in a debugger.

We never see assembly language under happier circumstances; it is always the bearer of bad news. I wanted to see if I could understand it like any other programming language. To make things easier, I decided to translate some of my own code into assembly language so I could focus on the assembly language syntax.

It was easier to figure out what the instructions meant because I knew what they were doing. Instead, the Ruby interpreter itself is compiled into machine language and runs my code using a virtual machine. But I wanted to see what a real machine would do, not a virtual one.

And because the LLVM system can also produce an assembly language version of the code it produces, using Crystal was the perfect way for me to see my Ruby code translated so a microprocessor could understand it. I started by writing an extremely simple program that adds 42 to a given integer: But only Crystal could produce a copy in assembly language: Most of this was the compiled version of the Crystal runtime library.

how to write a simple operating system in assembly language

Searching again I found the x86 assembly language version of my function: Next, I deleted all of the assembler directives, such as. Someday it would be interesting to learn about these, but I wanted to focus on the actual machine instructions.

And finally I pasted the the remaining code inside of my Ruby function.

The Assembler

Almost Easy to Read This code is almost easy to follow. I can guess what each instruction means: And from where to where?Apr 20,  · Introduction to Linux - A Hands on Guide This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter.

How to write a simple operating system in assembly language. Step 1: Write an operating system.

how to write a simple operating system in assembly language

Step 2: Compile it into assembly. How to write a simple operating system in assembly language Look at the source for some open source all-asm based operating systems.

From where you are starting, making your os load programs is a ways away, you .

Part 2: Data Representation

x86 operating system MikeOS is an operating system for x86 PCs, written in assembly language. It is a learning tool to show how simple bit, real-mode OSes work, with well-commented code and extensive documentation.

TUTORIALS POINT Simply Easy Learning ABOUT THE TUTORIAL Assembly Programming Tutorial Assembly language is a low-level programming language for a computer, or other. Preferred languages: C/C++, Java, and Ruby. I am looking for some helpful books/tutorials on how to write your own compiler simply for educational purposes.

I am most familiar with C/C++, Java, an.

LLVM Language Reference Manual — LLVM 8 documentation