kern_cons.c revision 27129 
1/*
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	from: @(#)cons.c	7.2 (Berkeley) 5/9/91
39 *	$Id: cons.c,v 1.51 1997/02/22 09:32:10 peter Exp $
40 */
41
42#include <sys/param.h>
43#ifdef DEVFS
44#include <sys/devfsext.h>
45#endif /*DEVFS*/
46#include <sys/systm.h>
47#include <sys/conf.h>
48#include <sys/kernel.h>
49#include <sys/reboot.h>
50#include <sys/sysctl.h>
51#include <sys/proc.h>
52#include <sys/tty.h>
53
54#include <machine/cpu.h>
55#include <machine/cons.h>
56
57/* XXX this should be config(8)ed. */
58#include "sc.h"
59#include "vt.h"
60#include "sio.h"
61static struct consdev constab[] = {
62#if NSC > 0
63	{ sccnprobe,	sccninit,	sccngetc,	sccncheckc,	sccnputc },
64#endif
65#if NVT > 0
66	{ pccnprobe,	pccninit,	pccngetc,	pccncheckc,	pccnputc },
67#endif
68#if NSIO > 0
69	{ siocnprobe,	siocninit,	siocngetc,	siocncheckc,	siocnputc },
70#endif
71	{ 0 },
72};
73
74static	d_open_t	cnopen;
75static	d_close_t	cnclose;
76static	d_read_t	cnread;
77static	d_write_t	cnwrite;
78static	d_ioctl_t	cnioctl;
79static	d_select_t	cnselect;
80
81#define CDEV_MAJOR 0
82static struct cdevsw cn_cdevsw =
83	{ cnopen,	cnclose,	cnread,		cnwrite,	/*0*/
84	  cnioctl,	nullstop,	nullreset,	nodevtotty,/* console */
85	  cnselect,	nommap,		NULL,	"console",	NULL,	-1 };
86
87static dev_t	cn_dev_t;
88SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLTYPE_OPAQUE|CTLFLAG_RD,
89	&cn_dev_t, sizeof cn_dev_t, "T,dev_t", "");
90static int cn_mute;
91SYSCTL_INT(_kern, OID_AUTO, consmute, CTLFLAG_RW, &cn_mute, 0, "");
92
93int	cons_unavail = 0;	/* XXX:
94				 * physical console not available for
95				 * input (i.e., it is in graphics mode)
96				 */
97
98static u_char cn_is_open;	/* nonzero if logical console is open */
99static u_char cn_phys_is_open;	/* nonzero if physical console is open */
100static d_close_t *cn_phys_close;	/* physical device close function */
101static d_open_t *cn_phys_open;	/* physical device open function */
102static struct consdev *cn_tab;	/* physical console device info */
103static struct tty *cn_tp;	/* physical console tty struct */
104#ifdef DEVFS
105void *cn_devfs_token;		/* represents the devfs entry */
106#endif /* DEVFS */
107
108void
109cninit()
110{
111	struct consdev *best_cp, *cp;
112
113	/*
114	 * Find the first console with the highest priority.
115	 */
116	best_cp = NULL;
117	for (cp = constab; cp->cn_probe; cp++) {
118		(*cp->cn_probe)(cp);
119		if (cp->cn_pri > CN_DEAD &&
120		    (best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
121			best_cp = cp;
122	}
123
124	/*
125	 * Check if we should mute the console (for security reasons perhaps)
126	 * It can be changes dynamically using sysctl kern.consmute
127	 * once we are up and going.
128	 *
129	 */
130        cn_mute = ((boothowto & (RB_MUTE
131			|RB_SINGLE
132			|RB_VERBOSE
133			|RB_ASKNAME
134			|RB_CONFIG)) == RB_MUTE);
135
136	/*
137	 * If no console, give up.
138	 */
139	if (best_cp == NULL) {
140		cn_tab = best_cp;
141		return;
142	}
143
144	/*
145	 * Initialize console, then attach to it.  This ordering allows
146	 * debugging using the previous console, if any.
147	 * XXX if there was a previous console, then its driver should
148	 * be informed when we forget about it.
149	 */
150	(*best_cp->cn_init)(best_cp);
151	cn_tab = best_cp;
152}
153
154void
155cninit_finish()
156{
157	struct cdevsw *cdp;
158
159	if (cn_tab == NULL)
160		return;
161
162	/*
163	 * Hook the open and close functions.
164	 */
165	cdp = cdevsw[major(cn_tab->cn_dev)];
166	cn_phys_close = cdp->d_close;
167	cdp->d_close = cnclose;
168	cn_phys_open = cdp->d_open;
169	cdp->d_open = cnopen;
170	cn_tp = (*cdp->d_devtotty)(cn_tab->cn_dev);
171	cn_dev_t = cn_tp->t_dev;
172}
173
174static int
175cnopen(dev, flag, mode, p)
176	dev_t dev;
177	int flag, mode;
178	struct proc *p;
179{
180	dev_t cndev, physdev;
181	int retval;
182
183	if (cn_tab == NULL)
184		return (0);
185	cndev = cn_tab->cn_dev;
186	physdev = (major(dev) == major(cndev) ? dev : cndev);
187	retval = (*cn_phys_open)(physdev, flag, mode, p);
188	if (retval == 0) {
189		if (dev == cndev)
190			cn_phys_is_open = 1;
191		else if (physdev == cndev)
192			cn_is_open = 1;
193	}
194	return (retval);
195}
196
197static int
198cnclose(dev, flag, mode, p)
199	dev_t dev;
200	int flag, mode;
201	struct proc *p;
202{
203	dev_t cndev;
204
205	if (cn_tab == NULL)
206		return (0);
207	cndev = cn_tab->cn_dev;
208	if (dev == cndev) {
209		/* the physical device is about to be closed */
210		cn_phys_is_open = 0;
211		if (cn_is_open) {
212			if (cn_tp) {
213				/* perform a ttyhalfclose() */
214				/* reset session and proc group */
215				cn_tp->t_pgrp = NULL;
216				cn_tp->t_session = NULL;
217			}
218			return (0);
219		}
220	} else if (major(dev) != major(cndev)) {
221		/* the logical console is about to be closed */
222		cn_is_open = 0;
223		if (cn_phys_is_open)
224			return (0);
225		dev = cndev;
226	}
227	return ((*cn_phys_close)(dev, flag, mode, p));
228}
229
230static int
231cnread(dev, uio, flag)
232	dev_t dev;
233	struct uio *uio;
234	int flag;
235{
236	if ((cn_tab == NULL) || cn_mute)
237		return (0);
238	dev = cn_tab->cn_dev;
239	return ((*cdevsw[major(dev)]->d_read)(dev, uio, flag));
240}
241
242static int
243cnwrite(dev, uio, flag)
244	dev_t dev;
245	struct uio *uio;
246	int flag;
247{
248	if ((cn_tab == NULL) || cn_mute)
249		return (0);
250	if (constty)
251		dev = constty->t_dev;
252	else
253		dev = cn_tab->cn_dev;
254	return ((*cdevsw[major(dev)]->d_write)(dev, uio, flag));
255}
256
257static int
258cnioctl(dev, cmd, data, flag, p)
259	dev_t dev;
260	int cmd;
261	caddr_t data;
262	int flag;
263	struct proc *p;
264{
265	int error;
266
267	if ((cn_tab == NULL) || cn_mute)
268		return (0);
269	/*
270	 * Superuser can always use this to wrest control of console
271	 * output from the "virtual" console.
272	 */
273	if (cmd == TIOCCONS && constty) {
274		error = suser(p->p_ucred, (u_short *) NULL);
275		if (error)
276			return (error);
277		constty = NULL;
278		return (0);
279	}
280	dev = cn_tab->cn_dev;
281	return ((*cdevsw[major(dev)]->d_ioctl)(dev, cmd, data, flag, p));
282}
283
284static int
285cnselect(dev, rw, p)
286	dev_t dev;
287	int rw;
288	struct proc *p;
289{
290	if ((cn_tab == NULL) || cn_mute)
291		return (1);
292
293	dev = cn_tab->cn_dev;
294
295	return ((*cdevsw[major(dev)]->d_select)(dev, rw, p));
296}
297
298int
299cngetc()
300{
301	int c;
302	if ((cn_tab == NULL) || cn_mute)
303		return (-1);
304	c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
305	if (c == '\r') c = '\n'; /* console input is always ICRNL */
306	return (c);
307}
308
309int
310cncheckc()
311{
312	if ((cn_tab == NULL) || cn_mute)
313		return (-1);
314	return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
315}
316
317void
318cnputc(c)
319	register int c;
320{
321	if ((cn_tab == NULL) || cn_mute)
322		return;
323	if (c) {
324		if (c == '\n')
325			(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
326		(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
327	}
328}
329
330static cn_devsw_installed = 0;
331
332static void
333cn_drvinit(void *unused)
334{
335	dev_t dev;
336
337	if( ! cn_devsw_installed ) {
338		dev = makedev(CDEV_MAJOR,0);
339		cdevsw_add(&dev,&cn_cdevsw,NULL);
340		cn_devsw_installed = 1;
341#ifdef DEVFS
342		cn_devfs_token = devfs_add_devswf(&cn_cdevsw, 0, DV_CHR,
343						  UID_ROOT, GID_WHEEL, 0600,
344						  "console");
345#endif
346	}
347}
348
349SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL)
350
351
352