Autonomous Micro Aerial Vehicles (MAVs), with a form factor of 10cm in diameter, are an emerging technology thanks to the broad applicability enabled by their onboard intelligence. However, these platforms are strongly limited in the onboard power envelope for processing, i.e., less than a few hundred mW, which confines the onboard processors to the class of simple microcontroller units (MCUs). These MCUs lack advanced security features opening the way to a wide range of cyber security vulnerabilities, from the communication between agents of the same fleet to the onboard execution of malicious code. This work presents an open source System on Chip (SoC) design that integrates a 64 bit Linux capable host processor accelerated by an 8 core 32 bit parallel programmable accelerator. The heterogeneous system architecture is coupled with a security enclave based on an open source OpenTitan root of trust. To demonstrate our design, we propose a use case where OpenTitan detects a security breach on the SoC aboard the MAV and drives its exclusive GPIOs to start a LED blinking routine. This procedure embodies an unconventional visual communication between two palm sized MAVs: the receiver MAV classifies the LED state of the sender (on or off) with an onboard convolutional neural network running on the parallel accelerator. Then, it reconstructs a high-level message in 1.3s, 2.3 times faster than current commercial solutions.

翻译：自主微型飞行器（MAV）直径约10厘米，凭借其机载智能的广泛适用性成为新兴技术。然而，这类平台在机载处理功耗方面受到严格限制（即低于数百毫瓦），导致其机载处理器仅能采用简单的微控制器单元（MCU）。这些MCU缺乏高级安全特性，从而为各类网络安全漏洞敞开了大门——从同机群代理间的通信到机载恶意代码的执行。本文提出一种开源片上系统（SoC）设计，集成了支持64位Linux操作的主处理器，并由8核32位并行可编程加速器进行加速。该异构系统架构与基于开源OpenTitan信任根的安全飞地相结合。为演示该设计，我们提出一个用例：OpenTitan检测到MAV机载SoC出现安全漏洞后，驱动其专用GPIO启动LED闪烁程序。该流程实现了一种非常规的两掌大小MAV间的视觉通信：接收端MAV利用运行于并行加速器的机载卷积神经网络分类发送端的LED状态（亮/灭），随后在1.3秒内重构高层级消息——速度较当前商业方案提升2.3倍。