ArcticOS

A bare-metal operating system with a custom kernel, written in C & ASM from scratch.

Not a Linux distro. Not Unix. Just a custom OS built from the ground up.

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Features

• 32-bit Protected Mode (i386/i686)
• GRUB2 Multiboot 1 bootloader
• VESA VBE framebuffer display (800x600+)
• Custom desktop manager
• PS/2 keyboard driver (US QWERTY)
• PIT 8253 timer (100Hz)
• CMOS Real Time Clock
• IDT + PIC 8259A interrupt handling
• GDT setup
• Built-in libc (no stdlib dependency)
• Custom Graphics Pipeline – 1-bit monochrome bitmap rendering with byte-aligned row strides for pixel-perfect assets.

Apps

• Clock – analog + digital clock using real RTC data
• Terminal – shell with built-in commands
• Text Editor – simple editor with basic keybindings

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Project Structure

arctic-os/
├── Makefile              # Build system
├── linker.ld             # Linker script
├── boot/
│   └── boot.asm          # Bootloader (ASM, Multiboot)
├── kernel/
│   ├── kernel.c          # Kernel entry point
│   ├── gdt.c             # Global Descriptor Table
│   ├── idt.c             # Interrupt Descriptor Table + PIC
|   ├── logo_data.c       # Monochrome logo bitmap data (13-byte stride)
│   └── desktop.c         # Desktop manager
├── drivers/
│   ├── framebuffer.c     # VESA VBE + 8x16 font + graphics
│   ├── keyboard.c        # PS/2 keyboard driver
│   ├── rtc.c             # Real Time Clock (CMOS)
│   └── timer.c           # PIT 8253 (100Hz)
├── apps/
│   ├── clock.c           # Analog + digital clock
│   ├── terminal.c        # Shell
│   └── editor.c          # Text editor
├── libc/
│   └── libc.c            # Custom C library
├── include/
│    ├── logo_data.h      # Headers, types, declarations
|    └── kernel.h         # Headers, types, declarations
└── grub/
    └── grub.cfg          # GRUB config

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Requirements

sudo apt install -y \
    nasm gcc gcc-multilib binutils make \
    grub-pc-bin grub-common xorriso mtools \
    qemu-system-x86 qemu-kvm

Optional (recommended) – i686 cross-compiler:

sudo apt install -y gcc-i686-linux-gnu
# Then in Makefile change CROSS_CC to: i686-linux-gnu-gcc

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Build & Run

# Build
make

# Create ISO
make iso

# Run in QEMU
make run

# Or manually
qemu-system-i386 -cdrom arcticos.iso -m 128M -vga std -no-reboot

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Controls

Key	Action
1	Open Clock
2	Open Terminal
3	Open Text Editor
ESC	Return to desktop

Terminal commands

help, time, uname, cpuid, uptime, meminfo, echo, color, clear, exit

Text Editor

BACKSPACE delete, ENTER new line, Ctrl+A line start, Ctrl+E line end, ESC exit

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Run on real hardware

# WARNING: This will overwrite the USB drive!
sudo dd if=arcticos.iso of=/dev/sdX bs=4M status=progress

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Technical Details

Property	Value
Architecture	i386/i686, 32-bit Protected Mode
Boot	GRUB2 Multiboot 1
Display	VESA VBE (800x600+)
Font	Built-in 8x16px bitmap (ASCII 32-127)
Keyboard	PS/2, US QWERTY
Timer	PIT 8253, 100Hz
RTC	CMOS 0x70/0x71, BCD + binary
Memory	Flat memory model, no MMU/paging
Interrupts	IDT, PIC 8259A, IRQ 0,1,8

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License

MIT