There is an ongoing trend in several embedded industries to consolidate multiple subsystems onto the same hardware platform. For example, in the automotive industry, network-connected infotainment starts to be deployed alongside safety-critical control systems (e.g., steering, brake, ABS). To guarantee the temporal and spatial isolation of these components with different criticalities/safety integrity levels (ASIL), it is nowadays common to rely on virtualization technology. However, there is an erroneous belief that hypervisors are the new magic bullet, working as transparent layers of software that provide perfect guarantees and have no impact on the overall system. In this paper, we provide a comprehensive picture of the state of affairs concerning the use of virtualization in the context of the so called mixed-criticality systems. While sharing our experience on the development of an open-source static partitioning hypervisor (Bao) and implementing the hardware virtualization support of a novel computer architecture (RISC-V), we will (i) cover the main problems and limitations currently affecting existing hypervisor solutions and (ii) discuss the (research) challenges and opportunities lying ahead of us.

With the growing ubiquity of Internet of Things (IoT), myriads of smart devices connect and share important information over the internet. In order to provide connectivity and interoperability of all the existing heterogeneous wireless devices, a full communication stack is proposed by the IoT Architecture Reference Model (IoT-ARM). From the sensor to the cloud, the proposed stack can be implemented on all IoT devices avoiding the battle for the wireless standard that will be adopted. This work in progress paper proposes an FPGA-based edge device for IoT, which uses SoC (System-on-Chip) FPGA technology to offload critical features of the communication stack to dedicated hardware, aiming to increase systems performance.

The increasing adoption of IoT devices highlights the urgent need for robust security solutions, particularly on low-end MCUs. However, these platforms typically lack the advanced security mechanisms found in higher-end processors, making them highly vulnerable to attacks. This paper presents an interoperable solution that enables Trusted Execution Environments (TEEs) on low-end MCUs, leveraging platform-specific hardware security primitives available in both ARMv7-M and RISC-V architectures. By complementing these primitives with software-based isolation techniques, the proposed solution achieves strong domain isolation even in resource-constrained devices. Additionally, the adoption of the GlobalPlatform API provides a common abstraction layer that decouples application development from platform-specific details, allowing trusted applications to run seamlessly across different MCU platforms. In the evaluation, we assessed the solutions through performance microbenchmarks and real-world applications, demonstrating their feasibility and the trade-offs between security and performance across different workloads.

The automotive industry is experiencing a massive paradigm shift. Cars are becoming increasingly autonomous, connected, and computerized. Modern electrical/electronic (E/E) architectures are pushing for an unforeseen functionality integration density, resulting in physically separate Electronic Control Units (ECUs) becoming virtualized and mapped to logical partitions within a single physical microcontroller (MCU). While functional safety (FuSa) has been pivotal for vehicle certification for decades, the increasing connectivity and advances have opened the door for a number of car hacks and attacks. This development drives (cyber-)security requirements in cars, and has paved the way for the release of the new security certification standard ISO21434. RISC-V has great potential to transform automotive computing systems, but we argue that current ISA/extensions are not ready yet. This paper provides our critical perspective on the existing RISC-V limitations, particularly on the upcoming WorldGuard technology, to address virtualized MCU requirements in line with foreseen automotive applications and ISO21434 directives. We then present our proposal for the required ISA extensions to address such limitations, mainly targeting initiator-side protection. Finally, we explain our roadmap towards a full open-source proof-of-concept (PoC), which includes extending QEMU, an open-source RISC-V core, and building a complete software stack.

In a world with an accelerated population aging, there is an increasingly interest in developing solutions for the elderly living assistance. The Internet of Things is a new reality that is completely changing our everyday life, and promises to revolutionize modern healthcare by enabling a more personalized, preventive and collaborative form of care. Aiming to combine these two important topics, this work presents an IoT-ready solution for the elderly living assistance which is able to monitor and register patients vital information as well as to provide mechanisms to trigger alarms in emergency situations. Its effective low-power/low-cost and wireless characteristics turns this solution suitable to be used anywhere and by anyone, in a discrete and comfortable wristband. Experiments demonstrated a good system performance for the implemented functionalities, and regarding the autonomy we obtained an average battery lifetime of 306 hours (around 12 days). For the working range, the system have proved to perform well within a range of 60 meters before the out-of-range warning being triggered.

Virtualization technology starts becoming more and more widespread in the embedded systems arena, driven by the upward trend for integrating multiple environments into the same hardware platform. The penalties incurred by standard software-based virtualization, altogether with the strict timing requirements imposed by real-time virtualization are pushing research towards hardware-assisted solutions. Among existing commercial off-the-shelf (COTS) technologies, ARM TrustZone promises to be a game-changer for virtualization, despite of this technology still being seen with a lot of obscurity and scepticism. In this paper we present a Lightweight TrustZoneassisted Hypervisor (LTZVisor) as a tool to understand, evaluate and discuss the benefits and limitations of using TrustZone hardware to assist virtualization. We demonstrate how TrustZone can be adequately exploited for meeting the real-time needs, while presenting a low performance cost on running unmodified rich operating systems. While ARM continues to spread TrustZone technology from the applications processors to the smallest of microcontrollers, it is undeniable that this technology is gaining an increasing relevance. Our intent is to encourage research and drive the next generation of TrustZone-assisted virtualization solutions.

With the advent of the Internet of Things (IoT), security has emerged as a major design goal for smart connected devices. This explosion in connectivity created a larger attack surface area. Software-based approaches have been applied for security purposes; however, these methods must be extended with security-oriented technologies that promote hardware as the root of trust. The ARM TrustZone can enable trusted execution environments (TEEs), but existing solutions disregard real-time needs. Here, the authors demonstrate why TrustZone is becoming a reference technology for securing IoT edge devices, and how enhanced TEEs can help meet industrial IoT applications real-time requirements.

In this paper the ClimaWin concept is introduced. The ClimaWin project's main goals are to improve both indoor air quality and the energy efficiency of new and refurbished buildings, through the use of novel green smart windows. Generally, in order to improve windows' energy efficiency better insulation materials are used in windows frames and glasses. However, this approach leads to a severe deterioration of indoor air quality (IAQ) especially in buildings that are not equipped with heating, ventilation and air conditioning (HVAQ) systems. The Climawin windows do not require wires neither for power nor for communications. The window is powered through a battery (for blind operation) and a solar panel, which makes it an ideal solution for retrofitting. In order to achieve the energy efficiency requirements, the Climawin system hardware, the microcontroller software architecture and the radio communication strategy were designed for low power consumption. Furthermore, all the information about the system status can be monitored and actuated using intuitive graphical applications developed for PCs and Android OS smartphones. A remote database keeps all the relevant information about the system, making it easy to detect any anomaly or even to adjust the control algorithm parameters from a remote location. A full-set of web services are also provided in order to simplify the communication with home automation systems.

The pervasive use of embedded computing systems in modern societies altogether with the industry trend towards consolidating workloads, openness and interconnectedness, have raised security, safety, and real-time concerns. Virtualization has been used as an enabler for safety and security, but research works have proven that it must be extended and improved with hardware-based security foundations. ARM Trustzone has been used for the realization of Trusted Environments, however in this case real-time requirements are completely disregarded. This work in progress paper presents FreeTEE, an embedded architecture that emphasizes and preserves the real-time properties of the system but still guarantees security from the outset. TrustZone technology is exploited to implement the basic building blocks of a Trusted Execution Environment (TEE) as a lower-priority thread of a RTOS. Preliminary results demonstrated that the real-time properties of the RTOS remain practically intact.

Nowadays, the growing complexity of embedded systems demands for configurability, variability and reuse. Conditional compilation and object-orientation are two of the most applied approaches in the management of system variability. While the former increases the code management complexity, the latter leverages the needed modularity and adaptability to simplify the development of reusable and customizable software at the expense of performance and memory penalty. This paper shows how C++ TMP (Template Metaprogramming) can be applied to manage the variability of an object-oriented operating system and at the same time get ride out of the performance and memory footprint overhead. In doing so, it will be statically generated only the desired functionalities, thus ensuring that code is optimized and adjusted to application requirements and hardware resources.