unknown            45 core/ptp_chdk.h int add_ptp_handler(int opcode, ptp_handler handler, int unknown);
unknown          1694 platform/generic/wrappers.c int add_ptp_handler(int opcode, ptp_handler handler, int unknown)
unknown          1697 platform/generic/wrappers.c     return _add_ptp_handler(opcode,handler,unknown);