- new modules/simulation directory to collect all simulators and related modules
- new Tools/simulation directory to collect and organize scattered simulation submodules, scripts, etc
- simulation module renamed to simulator_mavlink
- sih renamed to simulator_sih (not a great name, but I wanted to be clear it was a simulator)
- ignition_simulator renamed to simulator_ignition_bridge
- large sitl_target.cmake split by simulation option and in some cases pushed to appropriate modules
- sitl targets broken down to what's actually available (eg jmavsim only has 1 model and 1 world)
- new Gazebo consistently referred to as Ignition for now (probably the least confusing thing until we fully drop Gazebo classic support someday)
- cmake NuttX build wrapper compile in place instead of copying source tree to build directory
- slightly faster skipping necessary copying (depending on system)
- allows debugging in place
- easier to work directly in NuttX following official documentation
- simplifies overall build which should make it easier to resolve any remaining NuttX dependency issues in the build system
- the downside is switching back and forth between different builds always require rebuilding NuttX, but I think this is worth the improved developer experience
- also no longer builds px4io and bootloader in every single build, for most users these rarely change and we're wasting a lot of build time
Daniel M. Sahu