Error: L6218E: Undefined symbol _estack (referred from cm_backtrace.o).
Error: L6218E: Undefined symbol _etext (referred from cm_backtrace.o).
Error: L6218E: Undefined symbol _sstack (referred from cm_backtrace.o).
Error: L6218E: Undefined symbol _stext (referred from cm_backtrace.o).
Error: L6218E: Undefined symbol _estack (referred from cm_backtrace.o). Error: L6218E: Undefined symbol _etext (referred from cm_backtrace.o). Error: L6218E: Undefined symbol _sstack (referred from cm_backtrace.o). Error: L6218E: Undefined symbol _stext (referred from cm_backtrace.o).