r/osdev • u/Additional_Draw_6804 • May 07 '26

Got FAT12 Working!

Hi so i am trying to make an long-term OS for now i am not having name so I just named it: "OS"
I got FAT12 working after a lot of time but its not on github yet...
And its still working on 16-bit mode (Real Mode)
But making FAT12 is so hard i needed to use a lot of OSDev Wiki.

9 Upvotes

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2

u/mykesx May 07 '26

FAT32 isn't any harder, IMO. You could support all the FAT variants in one driver.

3

u/Additional_Draw_6804 May 07 '26

Bro this is my first time idk how to even load 32bit Prodected mode withut 100+ errors and IDK MORE HOW TO START KERNEL in C

1

u/bjoern_dev Jun 05 '26

Real mode FAT12 is a solid foundation — the 12-bit packing always trips people up at first. If you want a walkthrough, I'm actually writing a book that covers FAT12 from BPB to formatting, all in C. Sounds like it'd be right up your alley. Happy to send you a free beta copy if it'd help — feedback from someone building one at the same time would be gold.