CEST OS. Your modern simple operating system from scratch.

Overview

📍

Our goal is to make a modern simple kernel for learning purposes, not a fully optimized state-of-art operating system such as Ubuntu, Arch Linux, etc.

Demo

https://cest.sanchezcarlosjr.com/

Code

https://github.com/sanchezcarlosjr/cest

Keywords

operating system, kernel

Introduction

Background

Goals

Domain understanding

Functional requirements

A shell with input from an ASCII keyboard and output to the screen.

Non-Functional Requirements

Arch x86-64 bits.

English.

Our tech stack is NASM, clang, Make, C, and C++.

Since we follow standards, we deploy on the UEFI. Our operating system will be incompatible with BIOS.

We use QEMU for testing purposes because it is easier for kernel development than other options such as VirtualBox.

We follow POSIX.

The Open Group Base Specifications Issue 7, 2018 edition. (2022, September 11). Retrieved from https://pubs.opengroup.org/onlinepubs/9699919799.2018edition

Design

Monolithic structure.

An user.

General-purpose operating system.

No networking.

x86-64 arquitechture.

OS’s input is a keyboard and its output is video, nothing else.

cest
│
└───boot # uefi boot
   startup.h
└───lib # libraries such that users can build on top of them
   └───libc # standard C library
      stdio.h
      stdlib.h
      string.h
└───kernel # load arquitechture specific interfaces
  └───interrupt
  └───memory
  └───proc

Lessons

Step 0 Install tools

We suppose you know how to install the docker.

Clone repository

git clone [email protected]:sanchezcarlosjr/cest.git

docker compose up

Assignment

Process

References

https://rua.ua.es/dspace/bitstream/10045/124698/1/Desarrollo_de_un_kernel_academico_para_arquitecturas_Martinez_Garcia_Ernesto.pdf

ecomaikgolf. (2022, October 29). alma. Retrieved from https://github.com/ecomaikgolf/alma

https://forum.osdev.org/viewtopic.php?f=1&t=32412

Absurdponcho. (2022, October 29). PonchoOS. Retrieved from https://github.com/Absurdponcho/PonchoOS/tree/main

[edk2] Handling hardware interrupts in EFI. (2022, October 29). Retrieved from https://edk2-devel.narkive.com/ht2Bda8v/edk2-handling-hardware-interrupts-in-efi

JSLinux. (2021, January 09). Retrieved from https://bellard.org/jslinux

AT&T assembly