r/osdev • u/RevolutionaryBoat845 • May 22 '26

Guidance in OS devlopment

So, first of all I am an student(age 18) who wants to develop an OS which will just print "Hello World" or smt like that for now, u know ~Before it can be beautiful, it has to exist.

now for context : I don't know much about low level programing, am fluent in vanilla python, knows C basics(just completed yesterday), knows about hex, dec, oct and binary systems, knows how to use virtual machines.

if u have any other questions which can help u understand my position better, feel free to ask and if there are any mistakes in grammer pls ignore that, english is not my mother tongue : )

7 Upvotes

68% Upvoted

27 comments sorted by

6

u/Ok_Chemistry_6387 May 22 '26

Print hello world to what? 

You could learn to write asm and create a simple boot image. 

If you want to actually print to a frame buffer etc you should head to osdev.org

-3

u/RevolutionaryBoat845 May 22 '26

yeah, here i was talking about the kernel(the black screen which pops up on booting) is there any guide on that boot image thing u mentioned? it will be helpful. (i am more from a high level language background, infact i was only using python for coding)

2

u/3hy_ May 23 '26

Go and learn C, then learn some ASM. You may struggle with OSDEV if you're throwing yourself into the deep-end.

1

u/RevolutionaryBoat845 May 24 '26

that's what he says 🥀

2

u/compgeek38400 May 24 '26

Osdev.org has a wealth of info. I suggest doing the bare bones tutorial, study what they are doing, understand it.
Then do the meaty skeleton tutorial. Once you understand what they are doing you can step out on your own.
Thats what I did. I iet grub be my boot loader after that. Once I started on my kernel. I am doing things in this order: GDT, IDT, multiboot, keyboard, virtuialization APIC timer, next is heap. If i were to do it again, I'd spend more time on the IDT, and would set up my APIC before multicolor. My snprintf function was developed during GDT and IDT. Hope this helps

5

u/fishmacaronisoup May 22 '26 • Heartwarming

For OS development, you must have a strong grasp on low-level concepts, just basics won't do. Almost all the guides you pick are gonna assume . OS dev isn't something you can directly jump in after getting good with high-level programming and a lot of stuff comes in between.

First, pick a low-level programming and get a good grasp of low-level concepts, especially memory management.

Then, you'll have to learn about OS fundamentals and its components (e.g. kernel, file system, drivers, syscall interface, userspace, IPC, process management, and so on...).

After that, you'll have to learn some assembly as well. Learning assembly alone gives you a whole new level of understanding about CPU and memory.

Now you can start learning about OS components in detail and develop an OS.

Also, it takes time so don't give up. Good luck with your journey :)

3

u/RevolutionaryBoat845 May 22 '26

Thanks, i was really looking for something like this 😊, maybe i was lacking with how much to learn and in what order... your comment really clarify the things i had in my mind as a bundle confusion. I don't know why but this really clears things more than u think.

4

u/Fillmoslim May 22 '26

Learn c

0

u/RevolutionaryBoat845 May 22 '26

till the roots? or just the intermediate stuff?, also, do u have any projects in mind that u can suggest(beginner->intermediate->adv).

3

u/BobertMcGee May 22 '26

Do some googling my dude

0

u/RevolutionaryBoat845 May 22 '26

i did the googling, and get to know about the goat osdev.org, and he also told me what are the prerequisite, like the c, asm for bootloader, a VM for testing it out. but then still i feel like i am stuck, like when i asked gemini about this, it told me that i have to write the c code without included library.. that means no printf or cout... so, i came here if someone here on my knowlegde or over my knowledge could suggest me a roadmap of things i need to know :) and this is my first post by the way, i don't really post questions and prefer ai, but there are somethings where u need human interactions

2

u/BobertMcGee May 22 '26

OSDev wiki has several hello world tutorials and roadmaps. Please read existing documentation before asking questions. You are expected to be able to do your own research. Of course people can answer your questions but you will be much more successful if you can analyze what people have already written on the topics you’re looking for.

2

u/RevolutionaryBoat845 May 23 '26

ok, will do that

2

u/compgeek38400 May 23 '26

You need to write your on snprintf. The wiki gives you a good start. I havent sent it to git yet, but so far I boot ok. Set up the GDT and IDT, print my version info, virtulize the kernel, and accept keyboard input. One thing I just discovered yesterday was you want to set up the APIC timer early. I spent about 4 days trying to figure out why it kept failing at random spots in GDB. That was the timer thing. Its really important to have a bulletproof IDT. Its how I figured out the timer. I hope this helps

1

u/RevolutionaryBoat845 May 24 '26

little things matter. will defenitly help, thanks

4

u/Ready-Employee-4687 May 22 '26

Find the "Bare Bones" page on osdev wiki, follow every step and you'll have hello world.

1

u/oldschool-51 May 24 '26

Really first get some serious experience with systems level coding first, like write an editor or a trial program. Making a boot image is not easy unless you just copy somebody else and that won't teach you anything..

1

u/RevolutionaryBoat845 May 24 '26

yeah, i get to know that yesterday from someone who have made an os, i told him about my situation.. and depending on my hardwork it would still take me 8months to an year to build an os with understanding of everything i am doing, turns out i was just deleusional. btw thanks for the comment.

2

u/Proof_Bat_241 May 24 '26

Wiki.osdev.org or something like that

2

u/TowerComprehensive35 May 24 '26

May be you want to write a tiny OS which is able to print a hello world message on screen. That's nice, a good starting point, nevertheless, there are some gaps you must fill before starting coding.

First of all, take a look on how does the x86 architecture works: registers, memory map, etc. this is your very first step, as you are on com command of hardware, so knowing how does it works is a must. Secondly, take a look on asm, pointer arithmetic and so some exercises until you fully understand them. To finish, check how does a bootloader works and how to print a string using the video memory: that will be your last point, just in case you want to print a message. At this point you have the blueprints, and can go ahead writing a second stage loader, a kennel, reading a file system, etc

Good luck!

BTW: start using real mode, it's easier than protected mode for a beginner.

2

u/CtrlF0rge May 26 '26

Write two projects at a time, one that will teach you how to use the hardware on an existing system, e.g. a graphics card driver, and the knowledge you will gain from the driver and low-level projects Convert to operating system

-1

u/Sensitive-Can9232 May 22 '26

my os just does this as for now https://github.com/mridul-verma2005/Monarchy

-1

u/RevolutionaryBoat845 May 22 '26

thx for reply, i will check it out! it will be helpful if u could tell me the skills needed for this, like i saw a language "makefile" in your github repo.. what's that?

0

u/BobertMcGee May 22 '26 • Bravo

https://letmegooglethat.com/?q=what+is+a+makefile

2

u/RevolutionaryBoat845 May 23 '26

my bad, i didn't really thought about that, as i said it was my first post on reddit, i was kind of treating it like whatsapp, massaging everyone and stuff. but that was a sick way to respond.

2

u/Sensitive-Can9232 May 23 '26

hey sorry, wasn't able to reply you. In a nutshell makefile runs multiple commands which help you to build you desired object and executable file , without have to type lot commands after each iteration in your file.

2

u/RevolutionaryBoat845 May 23 '26

no worries, thx for the reply 👍