EndlOS - A Simple Operating System from Scratch

EndlOS is a minimalist operating system written in C and Assembly that implements basic OS functionality including graphics, window management, input handling, and task scheduling.

Features

• Custom Bootloader: Written in Assembly to initialize the system and switch to protected mode.
• Graphics System:
  • Basic pixel drawing and shape rendering.
  • Custom font rendering.
  • Double buffering for smooth graphics.
• Window Management:
  • Movable windows.
  • Window controls (close button).
  • Taskbar.
• Input Handling:
  • Mouse support with a custom cursor.
  • Keyboard input.
  • Event system.
• Task Management:
  • Simple task scheduler.
  • Priority-based execution.
  • Multiple concurrent tasks.

Prerequisites

To build and run EndlOS, you'll need:

• NASM (Netwide Assembler)
• GCC (with 32-bit support)
• LD (GNU Linker)
• QEMU (for emulation)
• Make

Ubuntu/Debian Setup

sudo apt-get update
sudo apt-get install nasm gcc-multilib qemu-system-x86 make

Windows Setup

• Install NASM
• Install MinGW (ensure you get the 32-bit version)
• Install QEMU
• Add all executables to your system PATH

Building

• The project uses a simple Makefile for building. The build process:
• Assembles the bootloader
• Compiles the kernel
• Links everything together
• Creates the final disk image

all: bootloader

bootloader:
	nasm boot/boot.asm -f bin -o boot/bin/boot.bin
	nasm boot/kernel_entry.asm -f elf -o boot/bin/kernel_entry.bin
	
	gcc -m32 -ffreestanding -c boot/final.c -o boot/bin/kernel.o
	ld -m elf_i386 -o boot/bin/kernel.img -Ttext 0x1000 boot/bin/kernel_entry.bin boot/bin/kernel.o

	objcopy -O binary -j .text boot/bin/kernel.img boot/bin/kernel.bin
	cat boot/bin/boot.bin boot/bin/kernel.bin > os.img

To build:

make

Running

• To run in QEMU

make run

Project Structure

boot/
  ├── boot.asm             # Bootloader implementation
  ├── kernel_entry.asm     # Kernel entry point
  ├── main.c               # Main kernel code
  ├── graphics.c           # Graphics implementation
  ├── input.c              # Input handling
  ├── task.c               # Task scheduler
  ├── graphics_elements.c   # UI elements
  ├── font.c               # Font definitions
  └── graphics.h           # Graphics declarations