Speaker
Description
In the flight software projects carried out at the University of Vienna, we prefer to work as close to the hardware as possible. The faster pace of projects that we face, coupled with the need to adapt early to next-generation processing architectures, has led us to develop a light-weight operating system, which offers the possibilities that we need, without putting any unnecessary restrictions on the software.
LeanOS emerged out of an evaluation study of the next-generation payload data processor Scalable Sensor Data Processor (SSDP) and has subsequently been improved to support LEON based platforms in general.
The primary design philosophy behind LeanOS is for it to "get out of the way". This means that all components are implemented such, that users ideally select their desired configuration of functionality and hardware drivers and supply an Application Software executable that is automatically loaded once the boot process is complete. If needed, library functions are provided, which enable interaction with operating system services, such as the creation of threads and memory allocation.
LeanOS is designed with Symmetric Multiprocessing (SMP) in mind and can be configured support the SPARC Reference Memory Management Unit (SRMMU), including Paging and Virtual Memory for address space separation. It comes with Loadable Kernel Module support, offering a means of dynamic reconfiguration and driver updates even at run-time. The kernel module infrastructure also provides an easy to use way of implementing custom extensions to the OS, without the need to fully understand its intricacies. Examples are custom hardware features, such as mass memory or ADCs. This approach reduces the time and effort needed in the re-use of the higher-tier application software, as abstraction layers can be introduced, allowing an identical interface to changing underlying components, while maintaining a short path to the hardware.
LeanOS will see its first full in-flight use in the Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) instrument flight software (IFSW), which is currently being developed. A subset of its components was already used in the CHEOPS IFSW.
Both IFSWs are open-source developments of the University of Vienna.
Summary
Overview of the current state of the LeanOS development.
| Paper submission | Yes |
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