Many of AdaCore's "community" versions are the full compiler and if they dont have builds available for your bareboard arch you can build it yourself or get one from gcc.

The only difference is that use of the special "GNAT.X" packages outside the standard runtime are under a GPL restriction and you would be required to export those dependencies as a separate lib and do open dev on it.

Otherwise you are free to sell or keep any trade secrets you want without giving AdaCore anything.