Use cases are required to validate the technology developed from the user’s viewpoint. This is the main purpose of the three use cases that will be eventually implemented in the project. These use-cases will validate the features of the NOEL-V processor and XtratuM XNG: a low-level benchmark execution, an on-board satellite software stack, and a command & data handling subsystem.
The first use case to develop will be the execution of low-level benchmarks, both bare metal execution and XNG XRE (XtratuM Runtime Environment, a minimal system to run applications with no guest operating system). This use case will validate the basic functionality of the architecture and will provide simple performance estimation to compare the architecture performance to other solutions available on the market. The several levels of such benchmark applications will include the checking for the compliance with RISC-V standards, some providing single-value performance scores, and the evaluation of the impact of the memory hierarchy and shared hardware resources on safety and security requirements.
The second use case will be an on-board satellite software stack, which will use the LVCUGEN framework. LVCUGEN is a generic on-board framework developed by the French National Center for Space Studies (CNES) using XtratuM and LithOS. The purpose of this framework is to provide common on-board functions which are re-usable for different missions to minimize the satellite integration effort and ease the testing activities. Through LVCUGEN, critical partitions performing typical operations of a satellite (such as ground-to-satellite communications, positioning, mission control, etc.) and non-critical partitions performing payload computation, such as image compression, run in the same computer without interfering one another thanks to XtratuM and innovative hardware features minimizing interference channels.
The last use case will be a Command & Data Handling subsystem. This representative application was originally developed as part of the EMC² Artemis project by Thales Alenia Space. The purpose of this use-case is to evaluate the usage of multi-core processors in the context of mini- and micro-satellite constellations. Both the LEON4FT-based GR740 SoC and a previous version of fentISS XtratuM hypervisor have been evaluated with regards to their ability to handle space and time partitioning in a multicore context, and to perform inter-partition communications. Porting the C&DH application to the De-RISC platform will allow us to directly compare the evolution of the time and space isolation support that are key requirements for safety and security, and to assess the mechanisms we propose with regards to these properties.
These three aerospace use cases will be executed as part of the De-RISC project to assess the safety and the security properties of the hardware+software project platform.
Figure: ground/satellite/High Altitude Pseudo-Satellites communication