nicolaOS is a hobby x86-64 operating system. This is a foundational project that successfully boots, initializes core system structures, and demonstrates basic kernel-level functionality.

After booting, the kernel initializes its components, prints a welcome message and status updates to the framebuffer, allocates and frees a small block of memory to test the heap, and then deliberately halts.

• Bootloader: Uses the Limine boot protocol.
• Core Structures:
  • Global Descriptor Table (GDT): Sets up a basic 64-bit GDT with null, code, and data segments.
  • Interrupt Descriptor Table (IDT): Initializes a 256-entry IDT and loads it.
• Interrupt Handling:
  • Remaps the PIC (Programmable Interrupt Controller).
  • Provides assembly stubs for the first 32 CPU exceptions.
  • Includes basic panic handlers for General Protection Faults (Exception 13) and Page Faults (Exception 14).
• Memory Management:
  • A custom, basic heap allocator (kmalloc/kfree) implemented in os/src/memory.c.
• Display:
  • Basic framebuffer output via Limine.
  • Font rendering using SSFN (Scalable Screen Font).
• Standard Library:
  • Minimal, custom implementations for string.h (strlen, memset, etc.) and stdlib.h (abort, kpanic).

You will need the following tools to build and run nicolaOS:

• A GNU/Linux environment
• make
• git
• qemu (specifically qemu-system-x86_64)
• xorriso
• nasm
• An x86-64 ELF cross-compiler (e.g., x86_64-elf-gcc, x86_64-elf-ld).

First, you must fetch the Limine bootloader:

make limine

This will clone the Limine repository into a local limine/ directory

To compile the kernel, create the bootable ISO, and launch QEMU, run:

make boot