When controlled from a debugger (build with INCLUDE_GDB_CONTROL macro);
when stopped due a EBREAK instruction; on a 'resume' command ('continue' in GDB),
was getting stuck. This is now working.
At this point, all debugger functionality (almost: see below) is working:
halt, step, breakpoints, resume, read/write gpr/fpr/csr, read/write memory.
Still todo: "NDM reset" (non-debug module reset).