Found a way that appears to work to detect if a sketch has our default serialEvantX functions, and that the users code has not implemented their own. Before on SerialX.begin() I would add that serial ports code to table of function calls to do the if SerialX.available() call serialEvernt..
But I now have a hacked up version where each of the event functions are in their own source file, along with a variable that is defined. Elsewhere I have those same variables defined with an attribute of ((weak)), so if our default implemention is pulled in it is defined with a value of 1, if the weak version is used because the user has their own implemention, then it is defined as a 0... So I can detect this at the begin method and only add the code to do the checks in yield if the user implemented it.
WARNING this also brought in changes for using XBar pins for CTS and RX pins... As I did not wish to split back out and have you maybe have to manually merge.
A few of the T4 and now T4.1 Serial ports support a CTS pin. One was previous fixed, added the others to tables.
Also T4.1 has Some Serial port pins in the area that the optional memory chips could be installed
There are two pins on the SDCard IO pins that are valid alternate pins for Serial5
Serial5.setRX or setTX.
These pin numbers changed from T4 to T4.1 so update table depending on which board.
Add some support for serialEventX calls when yield is called.
Currently keep table of which SerialX objects are Used (.begin called) and each has their own function which does the
if (Serial1.available()) serialEvent1();
Calling SerialX.end(), removes the call from the list. Also the default weak pointer serialEventX functions call the disable function, as to only be called once as no one is actually processing them...
At some point will integrate this with EventResponder
Kurt Eckhardt
PaulStoffregen