Add libraries that those boards depend on. This should be handled in the
future elsewhere (and once for each board), but for now let's make it
compile again.
Remove unnecessary includes, in particular the includes for specific
boards. The list of libraries for 'polygon' example was updated so that
the example compiles again.
This is going to be used by vehicles that already have an object with
setup/loop functions. The vehicle object will just implement the
HAL::Callbacks interface.
Move the macros to a single place and reduce the variations not based on
board, but based on
- The name of the entry-point function, specified by AP_MAIN;
- Whether it contains argc/argv arguments or not.
The goal here is that programs (vehicles and examples) don't need to
include all possible boards to define a main function. Further patches
will change the programs.
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'.
Caio Marcelo de Oliveira Filho
Andrew Tridgell
Jonathan Challinger