FreeWili Finder

A cross-platform C/C++ library for discovering and interfacing with FreeWili devices connected to a host system.

Overview

The FreeWili Finder library provides both modern C++ and C APIs to:

• Discover all connected FreeWili devices automatically
• Enumerate USB devices associated with each FreeWili
• Identify device types (Serial ports, Mass storage, FTDI/FPGA, etc.)
• Access device information (VID/PID, serial numbers, port paths)

Supported Devices

FREE-WILi2 components

Every FW2 presents an internal 7-port hub with its processors hanging off of it:

An ESP32 is only reported as part of a FREE-WILi2 when it is a child of the FW2 hub. A bare ESP32 plugged in elsewhere on the bus is not a standalone FreeWili device and is ignored.

The FW2 serial number is taken from the hub descriptor and is shared by the Main and FTDI components. The Debug Probe and Mass Storage report their own serials.

Features

• Dual API Support: Modern C++23 API with std::expected error handling, plus C API for maximum compatibility
• Language Bindings: Python (pyfwfinder) and Zig bindings
• Cross-Platform: Supports Windows, macOS, and Linux
• Type Safety: Strongly-typed USB device classification system
• Error Handling: Comprehensive error reporting and handling
• Memory Safe: RAII in C++, explicit memory management in C API
• Testing: Full test suite with GoogleTest integration

Quick Start

C++ API Example

#include <fwfinder.hpp>
#include <iostream>

int main() {
    if (auto devices = Fw::find_all(); devices.has_value()) {
        for (const auto& device : devices.value()) {
            std::cout << "Found: " << device.name
                     << " (Serial: " << device.serial << ")\n";

            // Get serial ports
            auto serials = device.getUSBDevices(Fw::USBDeviceType::Serial);
            for (const auto& serial : serials) {
                std::cout << "  Port: " << serial.port.value_or("Unknown") << "\n";
            }
        }
    } else {
        std::cerr << "Error: " << devices.error() << "\n";
    }
    return 0;
}

C API Example

#include <cfwfinder.h>
#include <stdio.h>

int main(void) {
    fw_freewili_device_t* devices[16];
    uint32_t device_count = 16;
    char error_msg[256];
    uint32_t error_size = sizeof(error_msg);

    if (fw_device_find_all(devices, &device_count, error_msg, &error_size) == fw_error_success) {
        printf("Found %u device(s)\n", device_count);

        for (uint32_t i = 0; i < device_count; ++i) {
            char name[64];
            fw_device_get_str(devices[i], fw_stringtype_name, name, sizeof(name));
            printf("Device: %s\n", name);
        }

        fw_device_free(devices, device_count);
    }
    return 0;
}

Building

Prerequisites

• CMake 3.20 or later
• C++23 compatible compiler (GCC 11+, Clang 14+, MSVC 2022+)
• Platform dependencies:
  • Linux: libudev-dev
  • macOS: Xcode command line tools
  • Windows: Windows SDK (SetupAPI, Cfgmgr32)

Build Instructions

# Clone the repository
git clone https://github.com/your-org/freewili-finder.git
cd freewili-finder

# Create build directory
mkdir build && cd build

# Configure
cmake .. -DCMAKE_BUILD_TYPE=Release

# Build
cmake --build .

# Run tests
ctest --output-on-failure

CMake Options

• FW_FINDER_BUILD_TESTS=ON/OFF - Build test suite (default: ON)
• FW_BUILD_C_API=ON/OFF - Build C API library (default: ON)
• FW_BUILD_STATIC=ON/OFF - Build static libraries (default: ON)
• FW_BUILD_EXAMPLES=ON/OFF - Build example applications (default: ON)

Python Bindings (pyfwfinder)

Requires Python 3.11+ and uv (recommended) or pip.

# Install with uv (recommended)
uv sync

# Or install with pip
pip install .

Usage:

import pyfwfinder

devices = pyfwfinder.find_all()
for device in devices:
    print(f"{device.name} (Serial: {device.serial})")
    for usb in device.usb_devices:
        print(f"  {usb.kind}: {usb.name}")

API Reference

C++ API (fwfinder.hpp)

Core Functions

namespace Fw {
    // Find all connected FreeWili devices
    auto find_all() noexcept -> std::expected<FreeWiliDevices, std::string>;

    // USB device type detection
    auto getUSBDeviceTypeFrom(uint16_t vid, uint16_t pid) -> USBDeviceType;
    auto getUSBDeviceTypeName(USBDeviceType type) -> std::string;
}

Device Types

enum class DeviceType {
    Unknown,           // Unknown device
    FreeWili,          // FREE-WILi (FW1)
    DEFCON2024Badge,   // DEFCON 2024 Badge
    DEFCON2025FwBadge, // DEFCON 2025 Badge
    UF2,               // UF2 Bootloader mode
    Winky,             // Winky
    FreeWili2,         // FREE-WILi2 (FW2)
};

enum class USBDeviceType {
    Hub,              // USB Hub (parent device)
    Serial,           // Serial Port (general)
    SerialMain,       // MainCPU Serial Port
    SerialDisplay,    // DisplayCPU Serial Port
    MassStorage,      // Mass Storage Device
    ESP32,            // ESP32 USB (JTAG/RTT)
    FTDI,             // FTDI/FPGA Device
    Other,            // Other USB device
    DebugProbe        // CMSIS-DAP Debug Probe (FREE-WILi2)
};

C API (cfwfinder.h)

Core Functions

// Find all devices
fw_error_t fw_device_find_all(fw_freewili_device_t** devices, uint32_t* count,
                              char* error_msg, uint32_t* error_size);

// Device validation and info
bool fw_device_is_valid(fw_freewili_device_t* device);
fw_error_t fw_device_get_str(fw_freewili_device_t* device, fw_stringtype_t type,
                             char* buffer, uint32_t buffer_size);

// USB device enumeration
fw_error_t fw_usb_device_begin(fw_freewili_device_t* device);
fw_error_t fw_usb_device_count(fw_freewili_device_t* device, uint32_t* count);
fw_error_t fw_usb_device_next(fw_freewili_device_t* device);
fw_error_t fw_usb_device_get_str(fw_freewili_device_t* device, fw_stringtype_t type,
                                 char* buffer, uint32_t buffer_size);
fw_error_t fw_usb_device_get_int(fw_freewili_device_t* device, fw_inttype_t type,
                                 uint32_t* value);

// Memory management
fw_error_t fw_device_free(fw_freewili_device_t** devices, uint32_t count);

Examples

Complete example applications are provided in the examples/ directory:

• basic_usage.cpp - Modern C++ API demonstration
• c_api_basic_usage.cpp - C API demonstration (compiled as C++)
• c_api_basic_usage_pure_c.c - Pure C implementation

Build and run examples:

cd build
make basic_usage_cpp basic_usage_c
./examples/basic_usage_cpp
./examples/basic_usage_c

Project Structure

freewili-finder/
├── include/
│   ├── fwfinder.hpp          # Main C++ API header
│   └── usbdef.hpp            # USB device definitions
├── src/
│   ├── fwfinder.cpp          # Core implementation
│   ├── fwfinder_linux.cpp    # Linux-specific code
│   ├── fwfinder_mac.cpp      # macOS-specific code
│   ├── fwfinder_windows.cpp  # Windows-specific code
│   └── usbdef.cpp            # USB device type mappings
├── c_api/
│   ├── include/cfwfinder.h   # C API header
│   ├── src/cfwfinder.cpp     # C API implementation
│   └── test/                 # C API tests
├── test/                     # C++ API tests
├── examples/                 # Example applications
├── bindings/
│   ├── python/               # Python bindings (pyfwfinder)
│   └── zig/                  # Zig bindings
└── pyproject.toml            # Python package configuration

Testing

The library includes comprehensive tests using GoogleTest:

cd build
ctest --output-on-failure

Tests cover:

• Device discovery functionality
• USB device type detection
• C API functionality
• Cross-platform compatibility
• Error handling scenarios

Platform Support

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Please ensure all tests pass and add tests for new functionality.

License

Copyright Free-Wili

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.