勾选的话回出来四个新的错误
..\OBJ\template.axf: Error: L6218E: Undefined symbol __fread_bytes_avail (referred from cad.o).
..\OBJ\template.axf: Error: L6218E: Undefined symbol mbsinit (referred from cad.o).
..\OBJ\template.axf: Error: L6218E: Undefined symbol __aeabi_assert (referred from dl_dxf.o).
..\OBJ\template.axf: Error: L6218E: Undefined symbol wmemmove (referred from ios.o).