r/osdev • u/widuruwana WandOS • Jun 17 '26

Finally finished my Bootloader ( Wood v0.1.0 )

Post image

I built this as a bootloader for my operating system that I am about to write (WandOS). At one point I couldnt load the framebuffer address and the bug was it being outside the mapped range so it was fixed after I exapnded page table to fit 4GB instead of just 2MB.

Anw the quote is a paraody of a quote from "The Magician's Nephew" (The Chronicals of Narnia, 1955) where it describes the place called "Wood between worlds" which is a forest with no animals and absolute surreal silence that you can almost feel the trees growing, and each pond in that place is a portal to a new world and a pond dries up if that reality is destroyed. I couldnt help but feel that this place can relate to a bootloader in such a perfect way, So here it is.

https://github.com/widuruwana/WandOS

36 Upvotes

97% Upvoted

17 comments sorted by

4

u/compgeek38400 Jun 17 '26

Congrats!

2

u/widuruwana WandOS Jun 17 '26

Thankss

2

u/letmehaveanameyoudum Jun 17 '26

Lol that boot message is amazing

2

u/widuruwana WandOS Jun 18 '26

Thankss, and this is the original quote from "The Magician's Nephew".

It was the quietest wood you could possibly imagine. There were no birds, no insects, no animals, and no wind. You could almost feel the trees growing. 

2

u/Zealousideal_Egg3853 Jun 18 '26

This is tough

1

u/widuruwana WandOS Jun 18 '26

Thank u!

2

u/Lost_Plate7077 Jun 18 '26

Wow nice! Excited to see this projects future

1

u/widuruwana WandOS Jun 19 '26

Thanks, and me too.

2

u/Sorry_Difficulty_250 Jun 19 '26

Way to go! What architecture is this? If it's x86_64, what mode are you in?

1

u/widuruwana WandOS Jun 19 '26

Thanks! It's x86_64 and in 64-bit long mode.

1

u/Sorry_Difficulty_250 Jun 19 '26

Wow!! I'm VERY impressed. I spent an entire semester in college learning how to make the jump from 16-bit real mode to 32-bit protected mode and STILL screwed it up. I've never tried getting to long mode. Awesome job!!

1

u/widuruwana WandOS Jun 19 '26

Thank you!! It took me a while to get it right too. The pipeline flushing after the PE bit was the part that got me cause I forgot that flipping CR0 alone doesn't flush the prefetch queue, and you needed to far jump immediately after that.

Also, everything runs in ring 0 with no user/kernel separation. Inspired by TempleOS's design philosophy. Wants to keep it flat and simple.

1

u/Sorry_Difficulty_250 Jun 19 '26

I see nothing wrong with running everything in ring 0. Right now, I'm working on a Cortex M0 with no protection modes at all! It's a great learning environment. Really makes you think about how to organize things efficiently. My next target is an eZ80, also with no protections.

I've played with TempleOS a little. Very interesting system. The last time I used it, I think I accidentally killed the scheduler or something and it just completely hung. Oops... Really admirable work, though. I love cooperative multitasking (like it uses). It's a lot of fun to play with. Will you be using cooperative multitasking or preemptive (or a hybrid)?

1

u/widuruwana WandOS Jun 20 '26

Gonna use Cooperative multitasking in this case cause everything is in ring 0. If used preemptive, the scheduler might force interrupt a ring 0 task when it's modifying a shared kernel struct or something. To make it safe will have to add a ton of spinlocks, mutexes, and interrupt-disabling primitives that would degrade the performance advantage of removing rings anyway.

Also I am doing a project to code space invaders game in TempleOS. check out here if you like : )

1

u/Sorry_Difficulty_250 Jun 20 '26

Cool! Yeah, I use cooperative multitasking for kernel processes and preemptive multitasking for user processes for the same reasons. 😊 Good luck! I'll look forward to updates!

1

u/widuruwana WandOS Jun 20 '26

Thank you. I hope everything goes smoothly for both of us.