Here is "MY problem" - as far as I can tell I am ONLY setting "Cross compiler prefix" as "arm-linux-gnueabihf-" and "Path" where it can be found as "/usr/bin".
I have no idea where this "prefix" came from - I have been at this project for a while , off and on.
It shows up in "include" tree on the Eclipse project form.
The code complies and runs on BCM2837 - RPi 3B.
Without changing any GCC setting the code compiles and sort of runs on BCM2835.
At least it starts.
I get a ton of errors and a simple , clean "hello word" obviously does not show in "TCF Debug Process Terminal" where I get all the coded messages and responses when I run same code on BCM2837.
I have been advised to check and possibly reinstall TCF Agent when connected to BCM2835.
I need to find, again, the real, not 3rd party copies, of TCF Agent installation tutorial.
However, if it solves the problem it kinda-of defeats the "universal" purpose of TCF.
Many thanks for your input.
Forgive OF ,senior moment, you are in Holland , right?