13.1. Operating System

GEISA LEE SHALL use Linux as the core operating system. The LEE platform implementer SHOULD use a Linux 6.x or greater kernel. A LEE platform may use an older version if needed, but it MUST provide the needed application isolation requirements as defined within the GEISA specification.

The attack surface and size of the Linux kernel and base libraries provided MUST be minimized. A LEE platform implementation SHOULD remove unnecessary components and libraries providing the platform and applications the required functionalities while being cognizant and intentional on minimizing the overall packages and services and should not be similar to a full typical Linux distribution.

There is no requirement for the underlying Linux kernel to support real-time features, and no real-time features are exposed to GEISA applications.

Applications, however, do specify their needed CPU and memory resource requirements in their Application manifests and operators SHOULD consider the finite resources available when deploying Applications. Applications SHOULD receive, over time, their resource allotment and not be starved to the point where metrological and waveform data is significantly delayed or lost.