On Tue, 9 Jan 2007, KIYOHARA Takashi wrote:

+++ sys/kern/tty_conf.c	6 Jan 2007 09:14:14 -0000
@@ -276,6 +276,7 @@
 		{ "ppp",		PPPDISC },
 		{ "strip",		STRIPDISC },
 		{ "hdlc",		HDLCDISC },
+		{ "bth4",		BTH4DISC },
 		{ NULL,			0 }
 	};
 	struct linesw *ldisc;

I do not think it is necessary to add the discipline to this table since
if it is not there, a unique legacy number will be assigned..

+++ sys/sys/ttycom.h	6 Jan 2007 09:14:16 -0000
@@ -160,5 +160,6 @@
 #define	PPPDISC		5		/* ppp discipline */
 #define	STRIPDISC	6		/* metricom wireless IP discipline */
 #define	HDLCDISC	9		/* HDLC discipline */
+#define	BTH4DISC	10		/* Bluetooth HCI UART (H4) discipline */

 #endif /* !_SYS_TTYCOM_H_ */

Neither is this necessary - TIOCSETD is maintained for backwards
compatibility but the TIOCSLINED ioctl should be used for new code, which
takes the name instead of a number (see tty(4))

regards,
iain