SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
int stopbits, int flowcontrol);
SR_PRIV int serial_set_paramstr(int fd, const char *paramstr);
SR_PRIV int serial_readline(int fd, char **buf, int *buflen,
SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
int stopbits, int flowcontrol);
SR_PRIV int serial_set_paramstr(int fd, const char *paramstr);
SR_PRIV int serial_readline(int fd, char **buf, int *buflen,