Sandro Pinto

Report from the killer immunoglobulin-like receptor (KIR) anthropology component of the 15th International Histocompatibility Workshop: worldwide variation in the KIR loci and further evidence for the co-evolution of KIR and HLA

The killer immunoglobulin-like receptor (KIR) anthropology component of the 15th International Histocompatibility Workshop (IHIWS) sought to explore worldwide population variation in the KIR loci, and to examine the relationship between KIR genes and their human leukocyte antigen (HLA) ligands. Fifteen laboratories submitted KIR genotype and HLA ligand data in 27 populations from six broad ethnic groups. Data were analyzed for correlations between the frequencies of KIR and their known HLA ligands. In addition, allelic typing was performed for KIR2DL2 and 3DL1 in a subset of populations. Strong and significant correlations were observed between KIR2DL2, 2DL3 genotype frequencies and the frequency of their ligand, HLA-C1. In contrast, only weak associations were seen for 3DL1, 3DS1 and the HLA-Bw4 ligand. Although some aspects of the correlations observed here differ from those reported in other populations, these data provide additional evidence of linked evolutionary histories for some KIR and HLA loci. Investigation of allele-level variation for the B haplotype locus KIR 2DL2 showed that two alleles, *001 and *003, predominate in all populations in this study. Much more allelic variation was observed for the A haplotype locus 3DL1, with several alleles observed at moderate frequencies and extensive variation observed between populations.

Towards a lightweight embedded virtualization architecture exploiting ARM TrustZone

Virtualization has been used as the de facto technology to allow multiple operating systems (virtual machines) to run on top of the same hardware platform. In the embedded systems domain, virtualization research has focused on the coexistence of real-time requirements with non-real-time characteristics. However, existent standard software-based virtualization solutions have been shown to negatively impact the overall system, especially in performance, memory footprint and determinism. This work in progress paper presents the implementation of an embedded virtualization architecture through commodity hardware. ARM TrustZone technology is exploited to implement a lightweight virtualization solution with low overhead and high determinism, corroborated by promising preliminary results. Research roadmap is also pointed and discussed.

We-care: An IoT-based health care system for elderly people

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.

Building IEEE 802.15.4 Accelerators for Heterogeneous Wireless Sensor Nodes

Bringing IPv6 connectivity to low-end wireless sensor nodes leads to considerable device resources utilization, e.g., central processing unit and energy, caused by the increased amount of data transferred over the network that needs to be handled. In order to reduce these overheads, this letter proposes an IEEE 802.15.4 accelerator for heterogeneous wireless sensor systems that target the Internet of Things sensing applications, which include on the same node, field-programmable gate array technology beside a microcontroller provided with wireless connectivity. The deployed solution implements the Third-level of filtering specified by the standard, and performs basic packet handling such as the detection of multiple receptions of the same frame. The obtained results show the benefits of including such accelerator on the reconfigurable computing unit, offering nearly 17 of overhead reduction. All filtering functionalities are executed by the accelerator to discard unneeded data frames, which avoids unnecessary interrupts to the operating system and increases the system availability up to 59.

IIoTEED: An Enhanced, Trusted Execution Environment for Industrial IoT Edge Devices

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.

Towards an FPGA-based edge device for the Internet of Things

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.

LTZVisor: TrustZone is the Key

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 TrustZone-assisted 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.

Porting SLOTH system to FreeRTOS running on ARM Cortex-M3

Traditionally, operating system (OSes) suffers from a bifid priority space dictated by the co-existence of threads managed by kernel scheduler and asynchronous interrupt handlers scheduled by hardware. On real-time systems, where reliability and determinism plays a critical role, this approach presents a noteworthy lack, as any interrupt handler can interrupt an execution thread, regardless of its priority. This paper presents the implementation of an unified priority space approach (SLOTH), handling each thread as an interrupt. A light-weight version of FreeRTOS was internally redesigned, to replace the software scheduler by a hardware one, which exploits a Commercial Off-The-Shelf (COTS) hardware interrupt controller, provided by ARM Cortex-M3. The results showed that our implementation solves the priority inversion problem, and simultaneously improves the system performance, reduces the memory footprint and simplifies maintainability.

Towards a TrustZone-Assisted Hypervisor for Real-Time Embedded Systems

Virtualization technology starts becoming more and more widespread in the embedded space. The penalties incurred by standard software-based virtualization is pushing research towards hardware-assisted solutions. Among the existing commercial off-the-shelf technologies for secure virtualization, ARM TrustZone is attracting particular attention. However, it is often seen with some scepticism due to the dual-OS limitation of existing state-of-the-art solutions. This letter presents the implementation of a TrustZone-based hypervisor for real-time embedded systems, which allows multiple RTOS partitions on the same hardware platform. The results demonstrate that virtualization overhead is less than 2 percent for a 10 milliseconds guest-switching rate, and the system remains deterministic. This work goes beyond related work by implementing a TrustZone-assisted solution that allows the execution of an arbitrary number of guest OSes while providing the foundation to drive next generation of secure virtualization solutions for resource-constrained embedded devices.

Towards an FPGA-based network layer filter for the Internet of Things edge devices

In the near future, billions of new smart devices will connect the big network of the Internet of Things, playing an important key role in our daily life. Allowing IPv6 on the low-power resource constrained devices will lead research to focus on novel approaches that aim to improve the efficiency, security and performance of the 6LoWPAN adaptation layer. This work in progress paper proposes a hardware-based Network Packet Filtering (NPF) and an IPv6 Link-local address calculator which is able to filter the received IPv6 packets, offering nearly 18% overhead reduction. The goal is to obtain a System-on-Chip implementation that can be deployed in future IEEE 802.15.4 radio modules.