4 research outputs found
A RECONFIGURABLE AND EXTENSIBLE EXPLORATION PLATFORM FOR FUTURE HETEROGENEOUS SYSTEMS
Accelerator-based -or heterogeneous- computing has become increasingly
important in a variety of scenarios, ranging from High-Performance Computing (HPC) to embedded systems. While most solutions use sometimes
custom-made components, most of today’s systems rely on commodity highend CPUs and/or GPU devices, which deliver adequate performance while
ensuring programmability, productivity, and application portability. Unfortunately, pure general-purpose hardware is affected by inherently limited
power-efficiency, that is, low GFLOPS-per-Watt, now considered as a primary metric. The many-core model and architectural customization can
play here a key role, as they enable unprecedented levels of power-efficiency
compared to CPUs/GPUs. However, such paradigms are still immature and
deeper exploration is indispensable.
This dissertation investigates customizability and proposes novel solutions
for heterogeneous architectures, focusing on mechanisms related to coherence and network-on-chip (NoC). First, the work presents a non-coherent
scratchpad memory with a configurable bank remapping system to reduce
bank conflicts. The experimental results show the benefits of both using a
customizable hardware bank remapping function and non-coherent memories for some types of algorithms. Next, we demonstrate how a distributed
synchronization master better suits many-cores than standard centralized
solutions. This solution, inspired by the directory-based coherence mechanism, supports concurrent synchronizations without relying on memory
transactions. The results collected for different NoC sizes provided indications about the area overheads incurred by our solution and demonstrated
the benefits of using a dedicated hardware synchronization support. Finally, this dissertation proposes an advanced coherence subsystem, based
on the sparse directory approach, with a selective coherence maintenance
system which allows coherence to be deactivated for blocks that do not require it. Experimental results show that the use of a hybrid coherent and
non-coherent architectural mechanism along with an extended coherence
protocol can enhance performance.
The above results were all collected by means of a modular and customizable heterogeneous many-core system developed to support the exploration
of power-efficient high-performance computing architectures. The system is
based on a NoC and a customizable GPU-like accelerator core, as well as
a reconfigurable coherence subsystem, ensuring application-specific configuration capabilities. All the explored solutions were evaluated on this real heterogeneous system, which comes along with the above methodological
results as part of the contribution in this dissertation. In fact, as a key
benefit, the experimental platform enables users to integrate novel hardware/software solutions on a full-system scale, whereas existing platforms
do not always support a comprehensive heterogeneous architecture exploration
Ein mehrschichtiges sicheres Framework für Fahrzeugsysteme
In recent years, significant developments were introduced within the vehicular domain, evolving the vehicles to become a network of many embedded systems distributed throughout the car, known as Electronic Control Units (ECUs). Each one of these ECUs runs a number of software components that collaborate with each other to perform various vehicle functions. Modern vehicles are also equipped with wireless communication technologies, such as WiFi, Bluetooth, and so on, giving them the capability to interact with other vehicles and roadside infrastructure. While these improvements have increased the safety of the automotive system, they have vastly expanded the attack surface of the vehicle and opened the door for new potential security risks. The situation is made worse by a lack of security mechanisms in the vehicular system which allows the escalation of a compromise in one of the non-critical sub-systems to threaten the safety of the entire vehicle and its passengers. This dissertation focuses on providing a comprehensive framework that ensures the security of the vehicular system during its whole life-cycle. This framework aims to prevent the cyber-attacks against different components by ensuring secure communications among them. Furthermore, it aims to detect attacks which were not prevented successfully, and finally, to respond to these attacks properly to ensure a high degree of safety and stability of the system.In den letzten Jahren wurden bedeutende Entwicklungen im Bereich der Fahrzeuge vorgestellt, die die Fahrzeuge zu einem Netzwerk mit vielen im gesamten Fahrzeug verteile integrierte Systeme weiterentwickelten, den sogenannten Steuergeräten (ECU, englisch = Electronic Control Units). Jedes dieser Steuergeräte betreibt eine Reihe von Softwarekomponenten, die bei der Ausführung verschiedener Fahrzeugfunktionen zusammenarbeiten. Moderne Fahrzeuge sind auch mit drahtlosen Kommunikationstechnologien wie WiFi, Bluetooth usw. ausgestattet, die ihnen die Möglichkeit geben, mit anderen Fahrzeugen und der straßenseitigen Infrastruktur zu interagieren. Während diese Verbesserungen die Sicherheit des Fahrzeugsystems erhöht haben, haben sie die Angriffsfläche des Fahrzeugs erheblich vergrößert und die Tür für neue potenzielle Sicherheitsrisiken geöffnet. Die Situation wird durch einen Mangel an Sicherheitsmechanismen im Fahrzeugsystem verschärft, die es ermöglichen, dass ein Kompromiss in einem der unkritischen Subsysteme die Sicherheit des gesamten Fahrzeugs und seiner Insassen gefährdet kann. Diese Dissertation konzentriert sich auf die Entwicklung eines umfassenden Rahmens, der die Sicherheit des Fahrzeugsystems während seines gesamten Lebenszyklus gewährleistet. Dieser Rahmen zielt darauf ab, die Cyber-Angriffe gegen verschiedene Komponenten zu verhindern, indem eine sichere Kommunikation zwischen ihnen gewährleistet wird. Darüber hinaus zielt es darauf ab, Angriffe zu erkennen, die nicht erfolgreich verhindert wurden, und schließlich auf diese Angriffe angemessen zu reagieren, um ein hohes Maß an Sicherheit und Stabilität des Systems zu gewährleisten