Simple Operating System (Siva-oS)

3 min readJul 24, 2020


Siva-oS is a simple operating system written in Assembly language.It can show the hardware informations of the computer.I referred some online material to get a better understanding of the operating system and all references attached below.In My Experience this reference meterials are really helped to me to developed this OS .


The kernel is the core of the Operating System. The computer controlled by the kernel. I got kernel code from JOSH — minimalOS article written on JOSH by Dr. Mohan Raj Dhanagopal and developed the code. In the kernel file have three segments, ‘.text’ , ‘.data’ , ‘.bss’.

    .text — code
.data — initialized data (Constants)
.bss — variable's size


nasm is for converting .asm files to .bin files. Before start making the operating system we need to download this with ubuntu terminal. Code is given below.

sudo apt-get install nasm


qemu is used for making the operating system run on our Ubuntu OS terminal.

sudo apt-get install qemu

How to build in Ubuntu

sudo bash ./

This will use NASM to assemble the bootloader, kernel and supplied programs, then write the bootloader to the mikeos.flp floppy disk image in the disk_images.

How to run on Ubuntu terminal

qemu-system-i386 -fda disk_images/mikeos.flp

Then qemu make the operating system run.Lets see the parts of the operating system.

files in Siva-oS

  1. source/ — entire OS source code.
  2. source/bootload/ — Source to generate bootload.bin ,that is added to the disk image when building.
  3. source/kernel.asm — can be called as the heart of the operating system.(Main part)
  4. disk_images— use disk images to protect media or to rebuild large multi-drive systems efficiently

Some commands from my OS

“help” command will show the all commands in my OS

“version” command will show the version of my OS

“info” command will show the all Hardware informations in my OS

“greet” command will show the greeting message

“giveXstar/s” command makes a opportunity to rate this OS

“exit” command will reboot this system

if you type any unknown commands ,system will display the error message

Source Code





BSc.(Hons) Software Engineering Undergraduate -University of kelaniya-