zorbaOS: A Multithreaded 32-bit x86 Operating System Kernel

zorbaOS is my from-scratch dive into operating systems at the lowest level. I wrote a custom x86 bootloader in assembly to handle real-mode initialization and the transition into 32-bit Protected Mode with hand-built GDT and IDT structures, then layered page-based virtual memory on top with a custom malloc/free heap allocator for process isolation. On top of that sits a Linux-inspired Virtual File System abstraction backed by a FAT16 driver, a cooperative/preemptive multitasking scheduler, and an ELF binary loader that runs user-space programs across Ring 0/Ring 3 privilege boundaries. Keyboard and PIC interrupt drivers feed into an interactive command-line shell so the whole thing is actually usable, not just theoretical.