Third OS (32-bit x86 Kernel)

A freestanding, 32-bit x86 toy operating system built from bare metal for Hack Club's Third Space sprint.

The kernel boots into Protected Mode via the Multiboot 1 standard, sets up a hardware-interfaced VGA text console, provides an in-memory virtual filesystem (RAMFS), and includes low-level debugging utilities (raw physical memory hex dumper and BIOS E820 memory map walker).

Toolchain & Requirements

To compile and emulate the kernel on Linux:

# Fedora / RHEL
sudo dnf install gcc nasm qemu-system-i386 qemu-ui-gtk

# Ubuntu / Debian
sudo apt install build-essential nasm qemu-system-x86

# Arch Linux
sudo pacman -S base-devel nasm qemu-system-x86

Quickstart

Compile and direct-boot into QEMU:

cd kernel
make run

Clean build artifacts:

make clean

Some Features I guess.

1. Bootstrapping & Entry (arch/x86/boot.s, linker.ld)

2. Video Console & Hardware Cursor (src/vga.c, include/io.h)

3. Freestanding Standard Library & Logger (src/string.c, src/kprintf.c)

4. In-Memory Virtual Filesystem (RAMFS) (src/fs.c)

5. Debugging & Inspection Tools (src/memdump.c)

Available Shell Commands

Type these directly into the kernel console in QEMU:

• help - Lists all available kernel commands
• clear - Clears the 80x25 screen and resets cursor to top-left
• ls - Lists all files and sizes currently stored in the RAMFS
• cat <file> - Displays the contents of a file
• write <file> <text> - Creates a new file in RAMFS or overwrites existing contents
• dump <addr> [len] - Inspects raw physical memory at <addr> in canonical hex/ASCII
• mmap - Displays the physical BIOS E820 RAM layout
• time - Reads real-world wall clock time from the CMOS Real-Time Clock uptime - Displays system uptime calculated from PIT timer hardware ticks