Contributors Forks Stargazers MIT

This project was originally done for a program in the Davidson Institute Of Science Education
during my final year of High School (Grade 12)
My target platform is x86_64 as it is by far the most common ISA currently
Do note that, while the final goal was (obviously...) a little too ambitious, most of my aims were met:

• Modern UEFI Bootloader, Using GNU-EFI & OVMF, written in C & inline assembly
• A Simple OS kernel, featuring:
  • Simple Font & Text Rendering, enabled by UEFI-GraphicsOutputProtocol
  • IA-32e Virtual Memory Support at the Higher Half - Kernel resides in the last 512GiB of the Virtual Address Space
  • Basic Utility Libraries, including but not limited to prink
  • Global Descriptor Table (Kind of required but i'll mention it anyways ;)
  • An Interrupt Descriptor Table
    • I have an abstraction to dynamically manage interrupts, see router.h
  • Basic ACPI Support, specifically with the I/O APIC & the Local APIC
  • Kernel Timers using HPET & Local APIC Drivers
  • A Physical Memory Manager using a Page-Granular (4096 Byte) Buddy Allocator Array
  • A Virtual Memory Manager using AVL Trees (Honestly this part is untested, and needs further improvements during scheduling features)
  • Atomics mini-library using GCC & clang Specific compiler extensions
  • SMP support, Initialization of all available cores and Core-specific data structures, each cpu needs its own:
    • Task State Segment
    • Stack
    • Many more scheduling structures... (That I've yet to implement & test :) )

• the 'legacy' branch contains the unmodified code I wrote back in 2021

The original motivation was genuine curiousity for lower-level mechanisms & abstractions during my first years of programming -
wanting to know how everything worked under the hood
I also found writing software to interact with hardware incredibly interesting

This project follows my premake5-workspace-template Template repository
Originally I only used a makefile, but I've graduated from that since then :)

• [NOTE]: This project is a heavily modified version of the 'barebones' branch

• premake5 (Generating makefiles)
• qemu
• mtools (Crafting an ISO)
• GDB/LLDB (I use lldb in this project)
• GCC Cross Compiler/Clang With LLD (for lld-link)

• Take extra caution when using prebuilt compilers, as they will automatically include system headers & libraries to the compilation commands, even on freestanding targets

• On Linux:

  Just get the tools required, there should not be many/if any problems

• On Windows:

  Personally I've had luck only with ELF-Cross-Tools & Msys2, specifically the following packages:

  • Msys2-Mingw64 Terminal (Only this Environment can supply mtools & clang for all I know)
  • mtools
  • clang
  • lld
  • lldb
  • clangd & friends
  • Do Note that ELF-Cross-Tools is used for the kernel, and msys2-mingw64-clang is used for the bootloader (I have not found a better setup yet...)

• clone the dev branch

git clone -b dev https://github.com/inonitz/PrimOS.git

• run the batch/sh file in misc/working_example

cd misc/working_example
./run.bat
./run.sh

git clone -b legacy https://github.com/inonitz/PrimOS.git
git clone -b dev https://github.com/inonitz/PrimOS.git
# Don't forget to add your own remote repo
git remote set-url origin your_github_username/your_fancy_os_kernel_name
git remote -v

call premake5 --help in the root of the repository

 premake5 cleanproj --proj=kernel 
 premake5 cleanbuild
 premake5 cleancfg
 premake5 cleanclangd
 premake5 cleanall 
 premake5 export-compile-commands
 premake5 ecc (same as export-compile-commands)

premake5 --cc=choose_specific_compiler ecc && premake5 --cc=choose_specific_compiler gmake
make config=Debug_amd64 -j 16 kernelimage

• bootloader
• kernel
• kernelimage - Packages the kernel & bootloader together to an ISO image

• Debug_amd64
• Release_amd64
• RelWithDebInfo_amd64
• You can add more Platforms/Configurations in the workspace.lua file (I only support AMD64)

• Utilizing Profile-Guided Optimization
• Automating setup with Docker
• Bringing back SMP Support (Relocation Errors)
• Syscalls
• Context Switching And Per-process Control Blocks
• Task Scheduling (MLFQ)
• ext2 file system
• USB 3.0 Support
  • Specifically USB Keyboard & Mouse Support is more relevant
• PCIe Driver Support
• Userspace (?)
• Profit (????)

I honestly Don't Care. open an issue if you're interested, I'll be sure to give it my attention

Distributed under the MIT License. See LICENSE file.

• PonchoOS For a great initial youtube guide & base skeleton for my project
• Jarod42 For the Improvements branch of export-compile-commands
• Best-README