Commit Graph

2 Commits

Author SHA1 Message Date
Caio Marcelo de Oliveira Filho 7662c2e73f AP_HAL_VRBRAIN: implement new AP_HAL functions
Implement the new AP_HAL functions and use them in the Scheduler when
possible.
2015-11-20 12:25:42 +09:00
Caio Marcelo de Oliveira Filho efbc7648b1 AP_HAL: create AP_HAL namespace and use for some HAL functionality
For certain basic functionality, there aren't much benefit to be able to
vary the implementation easily at runtime. So instead of using virtual
functions, use regular functions that are "resolved" at link time. The
implementation of such functions is provided per board/platform.

Examples of functions that fit this include: getting the current
time (since boot), panic'ing, getting system information, rebooting.

These functions are less likely to benefit from the indirection provided
by virtual interfaces. For more complex hardware access APIs the
indirection makes more sense and ease the testing (when we have it!).

The idea is that instead of calling

    hal.scheduler->panic("on the streets of london");

now use

    AP_HAL::panic("on the streets of london");

A less important side-effect is that call-site code gets
smaller. Currently the compiler needs to get the hal, get the scheduler
pointer, get the right function pointer in the vtable for that
scheduler. And the call must include an extra parameter ("this"). Now it
will be just a function call, with the address resolved at link time.

This patch introduces the first functions that will be in the namespace,
further patches will implementations for each board and then switch the
call-sites. The extra init() function allow any initial setup needed for
the functions to work.
2015-11-20 12:25:24 +09:00