New build configuration option RTEMS_QUALIFIED

[Sebastian Huber]

The goal of the RTEMS pre-qualification activity #3701 is a specified and validated subset of RTEMS. For users of the pre-qualified subset of RTEMS it is important to not accidentally use not pre-qualified features. One way to achieve this, is to build only the sources of the pre-qualified feature set. This customized build could be enabled by the new build configuration option RTEMS_QUALIFIED. If it is enabled, then only the pre-qualified subset of RTEMS is built and installed.

[Joel Sherrill]

Looking forward long term, the qualified source will be a superset of what is allowed per different profiles. For example, ESA's Space Profile has little overlap at the API level with the various POSIX profiles in the FACE Technical Standard. NASA is likely to have their own allowed profile.

How does this correspond to the subsets?

Is the plan to have a "full" qualified build versus builds that are tailored to specific subsets? Or to have both?

This appears to correspond to what I see from other RTOS vendors as their qualified product where everything that is qualified (to whatever degree) is all that is included in the build. But if this is putting the burden on RTEMS to ensure it has nothing beyond a specific user's profile, that may not be the best approach. The FACE Consortium has a Conformance Test Suite to check user code conformance to the FACE profiles. The OS can have much more available. Looking at this another way, it is not our responsibility to ensure conformance to some profile that we did not define.

[Sebastian Huber]

In the proposed approach there is just a single pre-qualified profile which is enabled by the RTEMS_QUALIFIED option. Multiple profiles would be also possible, however, this just increases the configuration complexity even more. Right now, only the space profile is pre-qualified. Maybe we should postpone the question if multiple profiles make sense or not into the future then more parts are pre-qualified.