This document provides resources for writing your own operating system, including virtual machines, build systems, compilers, programming languages, and hardware overview. It discusses structure padding in C, calling C from assembly, inline assembly on different platforms, interacting with hardware via memory-mapped I/O and I/O ports. It also covers the framebuffer, how to create an OS from scratch with listed source codes and books, and concludes with a demo.

1. The Linux Kernel Internal
Writing your own Operating System

2. Tools
• Virtual Machine:
– Qemu
– Virtual Box
• Build System:
make (Makefile)
• Compiler:
– GCC (C lang)
– Nasm (Assambly)
– LD (Linker)
• Programming Languages:
– C
– Assembly (Inline Assambly)
– High Level Language (Python, Perl)
• Host Operation System:
– Ubuntu 16.X

3. Hardware Overview

4. OS Overview

5. BornaOS Overview
• https://github.com/raminfp/BornaOS

6. What is padding struct and packed struct?
• More info : https://www.linkedin.com/pulse/why-structure-padding-required-c-
arsalan-saleem

7. Calling C Code From Assembly
• There are many different conventions for how to call C
code from assembly code
• https://gist.github.com/hibariya/d7fab1b5b0ca9ca2c6000bb
dc396849e

8. Inline Assembly
• Windows 32 bit:
• https://github.com/Cr4sh/WindowsRegistryRootkit/blo
b/master/src/meterpreter/dllmain.cpp
• Windows 64 bit/ARM:
• https://github.com/SinaKarvandi/x64-Driver-Inline-
Assembly/
• Linux :
• https://0xax.gitbooks.io/linux-
insides/content/Theory/linux-theory-3.html

9. Interacting with the Hardware
• Memory-mapped I/O:
• memory-mapped I/O then you can write to a specific memory
address and the hardware will be updated with the new data.
Example : (framebuffer, which will be discussed in more detail later.
For example, if you write the value 0x410F to address 0x000B8000,
you will see the letter A in white color on a black background)
• I/O ports :
• I/O ports then the assembly code instructions out and in must be used to
communicate with the hardware.
• https://github.com/raminfp/BornaOS/blob/master
/kernel/ports.c

10. The Framebuffer
• The framebuffer is a hardware device that is capable of
displaying a buffer of memory on the screen,
• Source :
• https://github.com/raminfp/BornaOS/blob/master/kernel/ke
rnel.c

11. How to create an OS from scratch?
• Source Code:
• https://github.com/cfenollosa/os-tutorial
• https://github.com/AlgorithMan-de/wyoos
• Books:
• https://littleosbook.github.io
• http://createyourownos.blogspot.com/
• Videos:
• https://www.youtube.com/watch?v=1rnA6wpF0o4&list=PLHh55M_Kq4OApWS
cZyPl5HhgsTJS9MZ6M
• https://youtu.be/l2wZf45ZcAg

12. The End
Demo