Add run method, that encapsulate any mainloop logic on behalf of the
client code. The setup/loop functions are passed via a HAL::Callbacks
interface. The AP_HAL_MAIN() macro should be kept as trivial as
possible.
This interface should be implemented by the existing vehicle objects. To
make easy for the examples (that don't have the equivalent of vehicle
objects), a FunCallbacks was added to bridge to the functions directly.
Instead of requiring every program to specify the HAL related modules,
let the build system do it (in practice everything we compiled depended
on HAL anyway). This allow including only the necessary files in the
compilation.
The switching between different AP_HAL was happening by giving different
definitions of AP_HAL_BOARD_DRIVER, and the programs would use it to
instantiate.
A program or library code would have to explicitly include (and depend)
on the concrete implementation of the HAL, even when using it only via
interface.
The proposed change move this dependency to be link time. There is a
AP_HAL::get_HAL() function that is used by the client code. Each
implementation of HAL provides its own definition of this function,
returning the appropriate concrete instance.
Since this replaces the job of AP_HAL_BOARD_DRIVER, the definition was
removed.
The static variables for PX4 and VRBRAIN were named differently to avoid
shadowing the extern symbol 'hal'.
The legacy EKF switches GPs aiding on on arming, whereas the new EKF switches it on based on GPS data quality.
This means the decision to arm and therefore the predicted solution flags must now reflect the actual status of the navigation solution as it will no longer change when motor arming occurs.
If high vibration levels cause offsets between the two, it switches to the accelerometer with lower vibration levels. The default behaviour is to use the average of both accelerometers.
Caio Marcelo de Oliveira Filho
Andrew Tridgell
Jonathan Challinger
Paul Riseborough
Randy Mackay