Artorias is a bare-metal bootloader written in x86 assembly and C that boots a custom kernel and initializes USB 2.0 devices through an EHCI (Enhanced Host Controller Interface) driver.

• Overview
• Documentation
• Features
• Requirements
• Building
• Limitations
• Resources

This project implements a boot sequence from power-on to USB device enumeration. It consists of:

• Stage 1 (MBR): A 512-byte Master Boot Record that relocates itself and loads stage 2
• Stage 2: Extended bootloader that enables protected mode and loads the kernel
• Kernel: 32-bit kernel with PCI bus enumeration, EHCI driver, and USB device detection

The complete documentation and tutorial for the bootloader code can be found on my Medium page titled "Writing a 32-bit x86 Bootloader from Scratch".

• Two-stage bootloader with MBR self-relocation
• Real mode to 32-bit protected mode transition
• Custom Global Descriptor Table (GDT) with flat memory model
• EHCI USB 2.0 Controller: Full implementation with asynchronous transfer scheduling
• VGA text mode, serial port, and PIT timer drivers
• Support for USB keyboards, mice, tablets, and storage devices
• Extracts manufacturer, product name, and serial number strings

• NASM
• QEMU
• GNU Make
• i686-elf-gcc cross-compiler
• i686-elf-ld linker

make run

make run-mouse

make run-kbd

make run-tablet

• No interrupts: Polling-based I/O only
• EHCI only: No UHCI/OHCI (USB 1.x) or XHCI (USB 3.x) support
• Read-only USB: Device detection only, no data transfer implementation
• QEMU-focused: Limited testing on real hardware

• Writing a Bootloader from Scratch - Carnegie Mellon University
• Rolling Your Own Bootloader - OSDev Wiki
• EHCI - OSDev Wiki
• EHCI Specification for USB - Intel

This project is licensed under the Apache License 2.0. See the LICENSE file for details.