dcons_os.c revision 178766 
1/*-
2 * Copyright (C) 2003,2004
3 * 	Hidetoshi Shimokawa. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *
16 *	This product includes software developed by Hidetoshi Shimokawa.
17 *
18 * 4. Neither the name of the author nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $FreeBSD: head/sys/dev/dcons/dcons_os.c 178766 2008-05-04 23:29:38Z peter $
35 */
36
37#include <sys/param.h>
38#if __FreeBSD_version >= 502122
39#include <sys/kdb.h>
40#include <gdb/gdb.h>
41#endif
42#include <sys/kernel.h>
43#include <sys/module.h>
44#include <sys/systm.h>
45#include <sys/types.h>
46#include <sys/conf.h>
47#include <sys/cons.h>
48#include <sys/consio.h>
49#include <sys/tty.h>
50#include <sys/malloc.h>
51#include <sys/priv.h>
52#include <sys/proc.h>
53#include <sys/ucred.h>
54
55#include <machine/bus.h>
56
57#ifdef __DragonFly__
58#include "dcons.h"
59#include "dcons_os.h"
60#else
61#include <dev/dcons/dcons.h>
62#include <dev/dcons/dcons_os.h>
63#endif
64
65#include <ddb/ddb.h>
66#include <sys/reboot.h>
67
68#include <sys/sysctl.h>
69
70#include <vm/vm.h>
71#include <vm/vm_param.h>
72#include <vm/pmap.h>
73
74#include "opt_comconsole.h"
75#include "opt_dcons.h"
76#include "opt_kdb.h"
77#include "opt_gdb.h"
78#include "opt_ddb.h"
79
80
81#ifndef DCONS_POLL_HZ
82#define DCONS_POLL_HZ	100
83#endif
84
85#ifndef DCONS_BUF_SIZE
86#define DCONS_BUF_SIZE (16*1024)
87#endif
88
89#ifndef DCONS_FORCE_CONSOLE
90#define DCONS_FORCE_CONSOLE	0	/* Mostly for FreeBSD-4/DragonFly */
91#endif
92
93#ifndef DCONS_FORCE_GDB
94#define DCONS_FORCE_GDB	1
95#endif
96
97#if __FreeBSD_version >= 500101
98#define CONS_NODEV	1
99#if __FreeBSD_version < 502122
100static struct consdev gdbconsdev;
101#endif
102#endif
103
104static d_open_t		dcons_open;
105static d_close_t	dcons_close;
106#if defined(__DragonFly__) || __FreeBSD_version < 500104
107static d_ioctl_t	dcons_ioctl;
108#endif
109
110static struct cdevsw dcons_cdevsw = {
111#ifdef __DragonFly__
112#define CDEV_MAJOR      184
113	"dcons", CDEV_MAJOR, D_TTY, NULL, 0,
114	dcons_open, dcons_close, ttyread, ttywrite, dcons_ioctl,
115	ttypoll, nommap, nostrategy, nodump, nopsize,
116#elif __FreeBSD_version >= 500104
117	.d_version =	D_VERSION,
118	.d_open =	dcons_open,
119	.d_close =	dcons_close,
120	.d_name =	"dcons",
121	.d_flags =	D_TTY | D_NEEDGIANT,
122#else
123#define CDEV_MAJOR      184
124	/* open */	dcons_open,
125	/* close */	dcons_close,
126	/* read */	ttyread,
127	/* write */	ttywrite,
128	/* ioctl */	dcons_ioctl,
129	/* poll */	ttypoll,
130	/* mmap */	nommap,
131	/* strategy */	nostrategy,
132	/* name */	"dcons",
133	/* major */	CDEV_MAJOR,
134	/* dump */	nodump,
135	/* psize */	nopsize,
136	/* flags */	D_TTY,
137#endif
138};
139
140#ifndef KLD_MODULE
141static char bssbuf[DCONS_BUF_SIZE];	/* buf in bss */
142#endif
143
144/* global data */
145static struct dcons_global dg;
146struct dcons_global *dcons_conf;
147static int poll_hz = DCONS_POLL_HZ;
148
149static struct dcons_softc sc[DCONS_NPORT];
150
151SYSCTL_NODE(_kern, OID_AUTO, dcons, CTLFLAG_RD, 0, "Dumb Console");
152SYSCTL_INT(_kern_dcons, OID_AUTO, poll_hz, CTLFLAG_RW, &poll_hz, 0,
153				"dcons polling rate");
154
155static int drv_init = 0;
156static struct callout dcons_callout;
157struct dcons_buf *dcons_buf;		/* for local dconschat */
158
159#ifdef __DragonFly__
160#define DEV	dev_t
161#define THREAD	d_thread_t
162#elif __FreeBSD_version < 500000
163#define DEV	dev_t
164#define THREAD	struct proc
165#else
166#define DEV	struct cdev *
167#define THREAD	struct thread
168#endif
169
170
171static void	dcons_tty_start(struct tty *);
172static int	dcons_tty_param(struct tty *, struct termios *);
173static void	dcons_timeout(void *);
174static int	dcons_drv_init(int);
175
176static cn_probe_t	dcons_cnprobe;
177static cn_init_t	dcons_cninit;
178static cn_term_t	dcons_cnterm;
179static cn_getc_t	dcons_cngetc;
180static cn_putc_t	dcons_cnputc;
181
182CONSOLE_DRIVER(dcons);
183
184#if defined(GDB) && (__FreeBSD_version >= 502122)
185static gdb_probe_f dcons_dbg_probe;
186static gdb_init_f dcons_dbg_init;
187static gdb_term_f dcons_dbg_term;
188static gdb_getc_f dcons_dbg_getc;
189static gdb_putc_f dcons_dbg_putc;
190
191GDB_DBGPORT(dcons, dcons_dbg_probe, dcons_dbg_init, dcons_dbg_term,
192    dcons_dbg_getc, dcons_dbg_putc);
193
194extern struct gdb_dbgport *gdb_cur;
195#endif
196
197#if (defined(GDB) || defined(DDB)) && defined(ALT_BREAK_TO_DEBUGGER)
198static int
199dcons_check_break(struct dcons_softc *dc, int c)
200{
201#if __FreeBSD_version >= 502122
202	int kdb_brk;
203#endif
204	if (c < 0)
205		return (c);
206
207#if __FreeBSD_version >= 502122
208	if ((kdb_brk = kdb_alt_break(c, &dc->brk_state)) != 0) {
209		switch (kdb_brk) {
210		case KDB_REQ_DEBUGGER:
211
212			if ((dc->flags & DC_GDB) != 0) {
213#ifdef GDB
214				if (gdb_cur == &dcons_gdb_dbgport) {
215					kdb_dbbe_select("gdb");
216					kdb_enter(KDB_WHY_BREAK,
217					    "Break sequence on dcons gdb port");
218				}
219#endif
220			} else
221				kdb_enter(KDB_WHY_BREAK,
222				    "Break sequence on dcons console port");
223			break;
224		case KDB_REQ_PANIC:
225			kdb_panic("Panic sequence on dcons console port");
226			break;
227		case KDB_REQ_BREAK:
228			kdb_reboot();
229			break;
230		}
231	}
232#else
233	switch (dc->brk_state) {
234	case STATE1:
235		if (c == KEY_TILDE)
236			dc->brk_state = STATE2;
237		else
238			dc->brk_state = STATE0;
239		break;
240	case STATE2:
241		dc->brk_state = STATE0;
242		if (c == KEY_CTRLB) {
243#if DCONS_FORCE_GDB
244			if (dc->flags & DC_GDB)
245				boothowto |= RB_GDB;
246#endif
247			breakpoint();
248		}
249	}
250	if (c == KEY_CR)
251		dc->brk_state = STATE1;
252#endif
253	return (c);
254}
255#else
256#define	dcons_check_break(dc, c)	(c)
257#endif
258
259static int
260dcons_os_checkc_nopoll(struct dcons_softc *dc)
261{
262	int c;
263
264	if (dg.dma_tag != NULL)
265		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_POSTREAD);
266
267	c = dcons_check_break(dc, dcons_checkc(dc));
268
269	if (dg.dma_tag != NULL)
270		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_PREREAD);
271
272	return (c);
273}
274
275static int
276dcons_os_checkc(struct dcons_softc *dc)
277{
278	EVENTHANDLER_INVOKE(dcons_poll, 0);
279	return (dcons_os_checkc_nopoll(dc));
280}
281
282#if defined(GDB) || !defined(CONS_NODEV)
283static int
284dcons_os_getc(struct dcons_softc *dc)
285{
286	int c;
287
288	while ((c = dcons_os_checkc(dc)) == -1);
289
290	return (c & 0xff);
291}
292#endif
293
294static void
295dcons_os_putc(struct dcons_softc *dc, int c)
296{
297	if (dg.dma_tag != NULL)
298		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_POSTWRITE);
299
300	dcons_putc(dc, c);
301
302	if (dg.dma_tag != NULL)
303		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_PREWRITE);
304}
305static int
306dcons_open(DEV dev, int flag, int mode, THREAD *td)
307{
308	struct tty *tp;
309	int unit, error, s;
310
311	unit = minor(dev);
312	if (unit != 0)
313		return (ENXIO);
314
315	tp = dev->si_tty;
316	tp->t_oproc = dcons_tty_start;
317	tp->t_param = dcons_tty_param;
318	tp->t_stop = nottystop;
319	tp->t_dev = dev;
320
321	error = 0;
322
323	s = spltty();
324	if ((tp->t_state & TS_ISOPEN) == 0) {
325		tp->t_state |= TS_CARR_ON;
326		ttyconsolemode(tp, 0);
327	} else if ((tp->t_state & TS_XCLUDE) &&
328	    priv_check(td, PRIV_TTY_EXCLUSIVE)) {
329		splx(s);
330		return (EBUSY);
331	}
332	splx(s);
333
334#if __FreeBSD_version < 502113
335	error = (*linesw[tp->t_line].l_open)(dev, tp);
336#else
337	error = ttyld_open(tp, dev);
338#endif
339
340	return (error);
341}
342
343static int
344dcons_close(DEV dev, int flag, int mode, THREAD *td)
345{
346	int	unit;
347	struct	tty *tp;
348
349	unit = minor(dev);
350	if (unit != 0)
351		return (ENXIO);
352
353	tp = dev->si_tty;
354	if (tp->t_state & TS_ISOPEN) {
355#if __FreeBSD_version < 502113
356		(*linesw[tp->t_line].l_close)(tp, flag);
357		ttyclose(tp);
358#else
359		ttyld_close(tp, flag);
360		tty_close(tp);
361#endif
362	}
363
364	return (0);
365}
366
367#if defined(__DragonFly__) || __FreeBSD_version < 500104
368static int
369dcons_ioctl(DEV dev, u_long cmd, caddr_t data, int flag, THREAD *td)
370{
371	int	unit;
372	struct	tty *tp;
373	int	error;
374
375	unit = minor(dev);
376	if (unit != 0)
377		return (ENXIO);
378
379	tp = dev->si_tty;
380	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td);
381	if (error != ENOIOCTL)
382		return (error);
383
384	error = ttioctl(tp, cmd, data, flag);
385	if (error != ENOIOCTL)
386		return (error);
387
388	return (ENOTTY);
389}
390#endif
391
392static int
393dcons_tty_param(struct tty *tp, struct termios *t)
394{
395	tp->t_ispeed = t->c_ispeed;
396	tp->t_ospeed = t->c_ospeed;
397	tp->t_cflag = t->c_cflag;
398	return 0;
399}
400
401static void
402dcons_tty_start(struct tty *tp)
403{
404	struct dcons_softc *dc;
405	int s;
406
407	dc = (struct dcons_softc *)tp->t_dev->si_drv1;
408	s = spltty();
409	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
410		ttwwakeup(tp);
411		return;
412	}
413
414	tp->t_state |= TS_BUSY;
415	while (tp->t_outq.c_cc != 0)
416		dcons_os_putc(dc, getc(&tp->t_outq));
417	tp->t_state &= ~TS_BUSY;
418
419	ttwwakeup(tp);
420	splx(s);
421}
422
423static void
424dcons_timeout(void *v)
425{
426	struct	tty *tp;
427	struct dcons_softc *dc;
428	int i, c, polltime;
429
430	for (i = 0; i < DCONS_NPORT; i ++) {
431		dc = &sc[i];
432		tp = ((DEV)dc->dev)->si_tty;
433		while ((c = dcons_os_checkc_nopoll(dc)) != -1)
434			if (tp->t_state & TS_ISOPEN)
435#if __FreeBSD_version < 502113
436				(*linesw[tp->t_line].l_rint)(c, tp);
437#else
438				ttyld_rint(tp, c);
439#endif
440	}
441	polltime = hz / poll_hz;
442	if (polltime < 1)
443		polltime = 1;
444	callout_reset(&dcons_callout, polltime, dcons_timeout, tp);
445}
446
447static void
448dcons_cnprobe(struct consdev *cp)
449{
450#ifdef __DragonFly__
451	cp->cn_dev = make_dev(&dcons_cdevsw, DCONS_CON,
452	    UID_ROOT, GID_WHEEL, 0600, "dcons");
453#elif __FreeBSD_version >= 501109
454	sprintf(cp->cn_name, "dcons");
455#else
456	cp->cn_dev = makedev(CDEV_MAJOR, DCONS_CON);
457#endif
458#if DCONS_FORCE_CONSOLE
459	cp->cn_pri = CN_REMOTE;
460#else
461	cp->cn_pri = CN_NORMAL;
462#endif
463}
464
465static void
466dcons_cninit(struct consdev *cp)
467{
468	dcons_drv_init(0);
469#if CONS_NODEV
470	cp->cn_arg
471#else
472	cp->cn_dev->si_drv1
473#endif
474		= (void *)&sc[DCONS_CON]; /* share port0 with unit0 */
475}
476
477static void
478dcons_cnterm(struct consdev *cp)
479{
480}
481
482#if CONS_NODEV
483static int
484dcons_cngetc(struct consdev *cp)
485{
486	struct dcons_softc *dc = (struct dcons_softc *)cp->cn_arg;
487	return (dcons_os_checkc(dc));
488}
489static void
490dcons_cnputc(struct consdev *cp, int c)
491{
492	struct dcons_softc *dc = (struct dcons_softc *)cp->cn_arg;
493	dcons_os_putc(dc, c);
494}
495#else
496static int
497dcons_cngetc(DEV dev)
498{
499	struct dcons_softc *dc = (struct dcons_softc *)dev->si_drv1;
500	return (dcons_os_getc(dc));
501}
502static int
503dcons_cncheckc(DEV dev)
504{
505	struct dcons_softc *dc = (struct dcons_softc *)dev->si_drv1;
506	return (dcons_os_checkc(dc));
507}
508static void
509dcons_cnputc(DEV dev, int c)
510{
511	struct dcons_softc *dc = (struct dcons_softc *)dev->si_drv1;
512	dcons_os_putc(dc, c);
513}
514#endif
515
516static int
517dcons_drv_init(int stage)
518{
519#if defined(__i386__) || defined(__amd64__)
520	quad_t addr, size;
521#endif
522
523	if (drv_init)
524		return(drv_init);
525
526	drv_init = -1;
527
528	bzero(&dg, sizeof(dg));
529	dcons_conf = &dg;
530	dg.cdev = &dcons_consdev;
531	dg.buf = NULL;
532	dg.size = DCONS_BUF_SIZE;
533
534#if defined(__i386__) || defined(__amd64__)
535	if (getenv_quad("dcons.addr", &addr) > 0 &&
536	    getenv_quad("dcons.size", &size) > 0) {
537#ifdef __i386__
538		vm_paddr_t pa;
539		/*
540		 * Allow read/write access to dcons buffer.
541		 */
542		for (pa = trunc_page(addr); pa < addr + size; pa += PAGE_SIZE)
543			*vtopte(KERNBASE + pa) |= PG_RW;
544		invltlb();
545#endif
546		/* XXX P to V */
547		dg.buf = (struct dcons_buf *)(vm_offset_t)(KERNBASE + addr);
548		dg.size = size;
549		if (dcons_load_buffer(dg.buf, dg.size, sc) < 0)
550			dg.buf = NULL;
551	}
552#endif
553	if (dg.buf != NULL)
554		goto ok;
555
556#ifndef KLD_MODULE
557	if (stage == 0) { /* XXX or cold */
558		/*
559		 * DCONS_FORCE_CONSOLE == 1 and statically linked.
560		 * called from cninit(). can't use contigmalloc yet .
561		 */
562		dg.buf = (struct dcons_buf *) bssbuf;
563		dcons_init(dg.buf, dg.size, sc);
564	} else
565#endif
566	{
567		/*
568		 * DCONS_FORCE_CONSOLE == 0 or kernel module case.
569		 * if the module is loaded after boot,
570		 * bssbuf could be non-continuous.
571		 */
572		dg.buf = (struct dcons_buf *) contigmalloc(dg.size,
573			M_DEVBUF, 0, 0x10000, 0xffffffff, PAGE_SIZE, 0ul);
574		dcons_init(dg.buf, dg.size, sc);
575	}
576
577ok:
578	dcons_buf = dg.buf;
579
580#if __FreeBSD_version < 502122
581#if defined(DDB) && DCONS_FORCE_GDB
582#if CONS_NODEV
583	gdbconsdev.cn_arg = (void *)&sc[DCONS_GDB];
584#if __FreeBSD_version >= 501109
585	sprintf(gdbconsdev.cn_name, "dgdb");
586#endif
587	gdb_arg = &gdbconsdev;
588#elif defined(__DragonFly__)
589	gdbdev = make_dev(&dcons_cdevsw, DCONS_GDB,
590	    UID_ROOT, GID_WHEEL, 0600, "dgdb");
591#else
592	gdbdev = makedev(CDEV_MAJOR, DCONS_GDB);
593#endif
594	gdb_getc = dcons_cngetc;
595	gdb_putc = dcons_cnputc;
596#endif
597#endif
598	drv_init = 1;
599
600	return 0;
601}
602
603
604static int
605dcons_attach_port(int port, char *name, int flags)
606{
607	struct dcons_softc *dc;
608	struct tty *tp;
609	DEV dev;
610
611	dc = &sc[port];
612	dc->flags = flags;
613	dev = make_dev(&dcons_cdevsw, port,
614			UID_ROOT, GID_WHEEL, 0600, name);
615	dc->dev = (void *)dev;
616	tp = ttyalloc();
617
618	dev->si_drv1 = (void *)dc;
619	dev->si_tty = tp;
620
621	tp->t_oproc = dcons_tty_start;
622	tp->t_param = dcons_tty_param;
623	tp->t_stop = nottystop;
624	tp->t_dev = dc->dev;
625
626	return(0);
627}
628
629static int
630dcons_attach(void)
631{
632	int polltime;
633
634#ifdef __DragonFly__
635	cdevsw_add(&dcons_cdevsw, -1, 0);
636#endif
637	dcons_attach_port(DCONS_CON, "dcons", 0);
638	dcons_attach_port(DCONS_GDB, "dgdb", DC_GDB);
639#if __FreeBSD_version < 500000
640	callout_init(&dcons_callout);
641#else
642	callout_init(&dcons_callout, 0);
643#endif
644	polltime = hz / poll_hz;
645	if (polltime < 1)
646		polltime = 1;
647	callout_reset(&dcons_callout, polltime, dcons_timeout, NULL);
648	return(0);
649}
650
651static int
652dcons_detach(int port)
653{
654	struct	tty *tp;
655	struct dcons_softc *dc;
656
657	dc = &sc[port];
658
659	tp = ((DEV)dc->dev)->si_tty;
660
661	if (tp->t_state & TS_ISOPEN) {
662		printf("dcons: still opened\n");
663#if __FreeBSD_version < 502113
664		(*linesw[tp->t_line].l_close)(tp, 0);
665		tp->t_gen++;
666		ttyclose(tp);
667		ttwakeup(tp);
668		ttwwakeup(tp);
669#else
670		ttyld_close(tp, 0);
671		tty_close(tp);
672#endif
673	}
674	/* XXX
675	 * must wait until all device are closed.
676	 */
677#ifdef __DragonFly__
678	tsleep((void *)dc, 0, "dcodtc", hz/4);
679#else
680	tsleep((void *)dc, PWAIT, "dcodtc", hz/4);
681#endif
682	destroy_dev(dc->dev);
683
684	return(0);
685}
686
687
688/* cnXXX works only for FreeBSD-5 */
689static int
690dcons_modevent(module_t mode, int type, void *data)
691{
692	int err = 0, ret;
693
694	switch (type) {
695	case MOD_LOAD:
696		ret = dcons_drv_init(1);
697		dcons_attach();
698#if __FreeBSD_version >= 500000
699		if (ret == 0) {
700			dcons_cnprobe(&dcons_consdev);
701			dcons_cninit(&dcons_consdev);
702			cnadd(&dcons_consdev);
703		}
704#endif
705		break;
706	case MOD_UNLOAD:
707		printf("dcons: unload\n");
708		callout_stop(&dcons_callout);
709#if __FreeBSD_version < 502122
710#if defined(DDB) && DCONS_FORCE_GDB
711#if CONS_NODEV
712		gdb_arg = NULL;
713#else
714		gdbdev = NULL;
715#endif
716#endif
717#endif
718#if __FreeBSD_version >= 500000
719		cnremove(&dcons_consdev);
720#endif
721		dcons_detach(DCONS_CON);
722		dcons_detach(DCONS_GDB);
723		dg.buf->magic = 0;
724
725		contigfree(dg.buf, DCONS_BUF_SIZE, M_DEVBUF);
726
727		break;
728	case MOD_SHUTDOWN:
729#if 0		/* Keep connection after halt */
730		dg.buf->magic = 0;
731#endif
732		break;
733	default:
734		err = EOPNOTSUPP;
735		break;
736	}
737	return(err);
738}
739
740#if defined(GDB) && (__FreeBSD_version >= 502122)
741/* Debugger interface */
742
743static int
744dcons_dbg_probe(void)
745{
746	int dcons_gdb;
747
748	if (getenv_int("dcons_gdb", &dcons_gdb) == 0)
749		return (-1);
750	return (dcons_gdb);
751}
752
753static void
754dcons_dbg_init(void)
755{
756}
757
758static void
759dcons_dbg_term(void)
760{
761}
762
763static void
764dcons_dbg_putc(int c)
765{
766	struct dcons_softc *dc = &sc[DCONS_GDB];
767	dcons_os_putc(dc, c);
768}
769
770static int
771dcons_dbg_getc(void)
772{
773	struct dcons_softc *dc = &sc[DCONS_GDB];
774	return (dcons_os_getc(dc));
775}
776#endif
777
778DEV_MODULE(dcons, dcons_modevent, NULL);
779MODULE_VERSION(dcons, DCONS_VERSION);
780