Compile Arduplane 3.8.0 with support for MavLink v1.0

Hi all,
I would need to compile the Arduplane firmware, v3.8.0 using mavlink v1.0 instead of v2.0.

As far as I understood, the messages generation (header files) is made automatically during the compilation.
What parameter should I set in order to do that?

Thank you.

The standard FW already supports both mavlink 1.0 and 2.0. No need to recompile anything. But you do need to tell MavProxy and/or Mission planner that you only want to use mavlink 1.0.

The ArduPilot boots in mavlink 1.0 mode, the ground station is the one the issues a request to change to 2.0. If the GCS does not do that, Ardupilot remains in 1.0 mode.