Operating System

Currently WIP. Supported and implemented features up to 2024-12-14 include (all custom implementations and are by us):

• 2 Stage bootloader with:
  • Dynamic physical address allocator
  • Long mode (64 bit)
  • MMU/Paging
  • Dynamic Kernel loader (with kernel-swapping)
• Drivers:
  • HDD/IDE drivers
  • VGA256 drivers
  • Keyboard drivers
• FAT16 filesystem
• Kernel ptmalloc implementation + mmap/munmap
• Image/Video rendering
• Partial libc (printf, FILE, mem/str, sin/cos ...)
• Precise clock & Date clock
• Interrupts + IRQ handling
• SSE (FPU) support
• Usermode (ring 3):
  • ELF loading
  • System calls (via syscall)
  • SMEP & SMAP
  • Multitasking of processes
  • Scheduler

Virtual Memory Structure

We took inspiration from Linux and mapped the kernel space in the non-canonical addresses, while keeping all the Process-related data in canonical memory.
We put the usermode stack right bellow the address hole, and the process data (.text, .rodata, .data, heap, ...) are loaded at a dynamic address, based on the ELF being run, keeping NULL not a valid address. Like so:

[Click to show]

Demo

The following video contains a technical demonstration of the current visual features of the OS:

Note that features like glibc-style ptmalloc, MMU, long mode and others, exist and are are used in the demo above, but aren't visible directly.

Building

You will need wget, mtools, direnv and Make (best GNUmake) installed.
First, (after cloning the project) install the buildtools with

make toolchain

After that, compile the bootloader and the kernel with

make

Running

The compiled OS will appear in hdd.img, which contains both the bootloader and the kernel.
You can run the OS on any x86-64 system as long as it has BIOS support.
One example (except running on bare metal) would be using qemu:

qemu-system-x86_64 -hda hdd.img

To both build and run with qemu you can use

make run