🦀 RustyNanoKVM

A high-performance, lightweight pure Rust rewrite of the NanoKVM IP-KVM software stack for RISC-V devices (Sipeed LicheeRV Nano / SG2002).

RustyNanoKVM replaces the heavy legacy daemon stack with a modular, memory-efficient Rust server (~2 MB binary) that interfaces directly with the Sophgo multimedia ISP driver for hardware-accelerated 1080p video capture, low-latency MJPEG streaming, USB HID emulation, and board management.

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🌟 Key Features

• ⚡ Hardware-Accelerated Video Capture: Direct FFI integration with the SG2002 video processing subsystem for 1080p@60fps HDMI input capture.
• 🎥 Real-Time MJPEG & Snapshot Streaming: Standard HTTP multipart (multipart/x-mixed-replace) streaming and single-frame 1080p JPEG snapshots.
• ⌨️ USB HID Emulation: Full keyboard and relative/absolute mouse control via Linux USB Gadget (/dev/hidg*).
• 🔌 Board Hardware Control: GPIO, ATX power button toggling, I2C communication, and SSD1306 OLED display management.
• 🪶 Ultra-Low Memory & CPU Footprint: ~2 MB compiled binary size using pure async Rust (Axum & Tokio), using a fraction of the system resources.

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📂 Workspace Architecture

The project is structured as a modular Cargo workspace:

crates/
├── nanokvm-server/   # Main Axum HTTP & WebSocket API server
├── nanokvm-vision/   # Hardware video capture (FFI bindings & MJPEG/H.264 stream logic)
├── nanokvm-hid/      # USB Gadget HID keyboard, mouse, and keycode translation
├── board-support/    # Hardware peripherals (GPIO, ATX power, I2C, OLED display, QR codes)
└── nanokvm-core/     # Configuration loader, errors, and common types

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🛠️ Building & Testing

Prerequisites

• Rust 1.85+ (rustup target add riscv64gc-unknown-linux-musl)
• Cross-compiler toolchain for RISC-V: riscv64-linux-gnu-gcc

Local Development & Unit Tests

Run workspace unit tests using mock hardware mode:

cargo test --workspace --features mock

Cross-Compiling for NanoKVM (SG2002 RISC-V)

To build the release binary for the target RISC-V hardware:

CC_riscv64gc_unknown_linux_musl=riscv64-linux-gnu-gcc \
cargo build --target riscv64gc-unknown-linux-musl --release

The compiled binary will be generated at: target/riscv64gc-unknown-linux-musl/release/nanokvm-server

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🚀 Deployment to NanoKVM Device

1. Transfer Binary & Web Frontend:

   # Copy the compiled binary
   scp target/riscv64gc-unknown-linux-musl/release/nanokvm-server root@<nanokvm-ip>:/tmp/server/nanokvm-server
   
   # Copy static web assets
   scp -r web root@<nanokvm-ip>:/tmp/server/

2. Run Server on Device:

   ssh root@<nanokvm-ip>
   LD_LIBRARY_PATH=/tmp/server/dl_lib /lib/ld-musl-riscv64v0p7_xthead.so.1 /tmp/server/nanokvm-server

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📡 API Reference

Endpoint	Method	Description
/api/stream/mjpeg	GET	Continuous HTTP MJPEG stream (multipart/x-mixed-replace)
/api/stream/snapshot	GET	Single 1080p JPEG snapshot image (image/jpeg)
/api/application/info	GET	System and server metadata
/api/application/version	GET	Server version
/api/hid/keyboard	POST	Send keyboard input events
/api/hid/mouse	POST	Send mouse movement and button events
/api/vm/power/short	POST	Trigger ATX power button short press
/api/vm/power/long	POST	Trigger ATX power button long press (force off)
/api/vm/reset	POST	Trigger ATX reset button press

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📜 License

Distributed under the MIT License.