https://github.com/barrettotte/enki-os
A basic x86 kernel to learn how operating systems get from BIOS to userland
https://github.com/barrettotte/enki-os
hobby-kernel operating-system os-kernel x86-kernel
Last synced: 14 days ago
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A basic x86 kernel to learn how operating systems get from BIOS to userland
- Host: GitHub
- URL: https://github.com/barrettotte/enki-os
- Owner: barrettotte
- License: mit
- Created: 2021-09-12T21:07:16.000Z (over 3 years ago)
- Default Branch: master
- Last Pushed: 2022-05-01T16:11:44.000Z (almost 3 years ago)
- Last Synced: 2025-03-25T00:51:12.511Z (about 1 month ago)
- Topics: hobby-kernel, operating-system, os-kernel, x86-kernel
- Language: C
- Homepage:
- Size: 225 KB
- Stars: 8
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# enki-os
A basic x86 kernel to learn how operating systems get from BIOS to userland.
This is my first dive into the deep world of operating systems.
I hope to make another kernel in the future using the things I learned here.
This one still needs a lot of love and care it probably won't get.
Named after [Enki](https://en.wikipedia.org/wiki/Enki),
Sumerian god of water, knowledge, crafts, and creation.
## Features / Goals
- [x] Custom bootloader
- [x] FAT-16 file system (except `fwrite`)
- [x] PS/2 keyboard driver
- [x] Static ELF file loading
- [x] Partial LibC
- [x] Process create/manage via TSS
- [x] Userland with basic shell
- [x] Basic Multitasking (timer based)
## Building Locally
- Install dependencies and build cross compiler: `make toolchain`
- Build OS image: `make`
- Build OS image and launch in QEMU: `make qemu`
- Build OS image and launch with GDB connected to QEMU: `make debug`
## TODO Items
- Proper trapping/exception handling
- Shift key
- Scrolling terminal
- Cursor support
- Clear terminal
- Init Floating Point Unit (FPU)
- Reboot command
- ACPI
- PC speaker support
- Terminal color support
- Abstraction over PIC
- Abstraction over timer
- Gather system info and print on startup (memory, timer, etc)
- Stack smash protector
- Multiboot header
- Dockerfile with toolchain installed? Github action?
## Limitations
- Lazy A20 line enable; Could potentially fail on some systems
- Memory fragmentation
- Only one drive supported (master - drive 0)
- Missing FAT16 write
- ELF file loading loads entire file into heap memory...
- Only supports loading static ELF files
- Simple multitasking via timer
- Limited process control (no fork or exec)
- No threading
- Probably a lot more I'm forgetting...
## References
- [OSDev.org](https://wiki.osdev.org/Main_Page)
- [BrokenThorn OS Dev](http://www.brokenthorn.com/Resources/OSDevIndex.html)
- [x86 and amd64 instruction set](https://www.felixcloutier.com/x86/)
- [Ralf Brown Interrupt List](https://www.ctyme.com/rbrown.htm)
- [Operating Systems: Three Easy Pieces](https://pages.cs.wisc.edu/~remzi/OSTEP/)
- [Little Book About OS Development](https://littleosbook.github.io/)
- [PC Interrupts: A Programmer's Reference to BIOS, DOS, and Third-Party Calls](https://www.amazon.com/PC-Interrupts-Programmers-Reference-Third-Party/dp/0201624850)
- [Executable and Linkable Format (ELF)](https://refspecs.linuxfoundation.org/elf/elf.pdf)