2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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. Neither the name of the University 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.
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
34 * from: @(#)cons.c 7.2 (Berkeley) 5/9/91
35 * $FreeBSD: src/sys/kern/tty_cons.c,v 1.81.2.4 2001/12/17 18:44:41 guido Exp $
39 #include "opt_comconsole.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
45 #include <sys/kernel.h>
48 #include <sys/reboot.h>
49 #include <sys/sysctl.h>
52 #include <sys/msgport.h>
53 #include <sys/msgport2.h>
54 #include <sys/device.h>
58 #include <machine/cpu.h>
60 static d_open_t cnopen;
61 static d_close_t cnclose;
62 static d_read_t cnread;
63 static d_write_t cnwrite;
64 static d_ioctl_t cnioctl;
65 static d_kqfilter_t cnkqfilter;
67 static int cnintercept(struct dev_generic_args *ap);
70 static struct dev_ops cn_ops = {
71 { "console", 0, D_TTY | D_MPSAFE },
77 .d_kqfilter = cnkqfilter,
80 static struct dev_ops cn_iops = {
81 { "intercept", 0, D_TTY | D_MPSAFE },
82 .d_default = cnintercept
85 static struct dev_ops *cn_fwd_ops;
88 //XXX: get this shit out! (alexh)
90 SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
91 &cn_udev, sizeof cn_udev, "T,udev_t", "");
96 #ifdef BREAK_TO_DEBUGGER
97 int break_to_debugger = 1; /* CTL-ALT-ESC on system keyboard */
99 int break_to_debugger = 0;
101 TUNABLE_INT("kern.break_to_debugger", &break_to_debugger);
102 SYSCTL_INT(_kern, OID_AUTO, break_to_debugger, CTLFLAG_RW,
103 &break_to_debugger, 0, "");
105 #ifdef ALT_BREAK_TO_DEBUGGER
106 int alt_break_to_debugger = 1; /* CR ~ ^B on serial port */
108 int alt_break_to_debugger = 0;
110 TUNABLE_INT("kern.alt_break_to_debugger", &alt_break_to_debugger);
111 SYSCTL_INT(_kern, OID_AUTO, alt_break_to_debugger, CTLFLAG_RW,
112 &alt_break_to_debugger, 0, "");
114 int cons_unavail = 0; /* XXX:
115 * physical console not available for
116 * input (i.e., it is in graphics mode)
118 int sysbeep_enable = 1;
120 static u_char cn_is_open; /* nonzero if logical console is open */
121 static int openmode, openflag; /* how /dev/console was openned */
122 static cdev_t cn_devfsdev; /* represents the device private info */
123 static u_char cn_phys_is_open; /* nonzero if physical device is open */
124 static u_char console_pausing; /* pause after each line during probe */
125 static char *console_pausestr=
126 "<pause; press any key to proceed to next line or '.' to end pause mode>";
128 struct consdev *cn_tab; /* physical console device info */
129 struct consdev *gdb_tab; /* physical gdb debugger device info */
131 SYSCTL_INT(_kern, OID_AUTO, sysbeep_enable, CTLFLAG_RW, &sysbeep_enable, 0, "");
132 static uint32_t console_rdev;
133 SYSCTL_INT(_kern, OID_AUTO, console_rdev, CTLFLAG_RW,
134 &console_rdev, 0, "");
136 CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
137 SET_DECLARE(cons_set, struct consdev);
142 struct consdev *best_cp, *cp, **list;
145 * Workaround for token acquisition and releases during the
146 * console init. For some reason if lwkt_gettoken()'s mpcount
147 * optimization is turned off the console init blows up. It
148 * might be trying to kprintf() something in the middle of
151 lwkt_gettoken(&tty_token);
154 * Check if we should mute the console (for security reasons perhaps)
155 * It can be changes dynamically using sysctl kern.consmute
156 * once we are up and going.
159 cn_mute = ((boothowto & (RB_MUTE
162 |RB_ASKNAME)) == RB_MUTE);
165 * Find the first console with the highest priority.
168 SET_FOREACH(list, cons_set) {
170 if (cp->cn_probe == NULL)
173 if (cp->cn_pri > CN_DEAD && cp->cn_probegood &&
174 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
179 * If no console, give up.
181 if (best_cp == NULL) {
182 if (cn_tab != NULL && cn_tab->cn_term != NULL)
183 (*cn_tab->cn_term)(cn_tab);
188 * Initialize console, then attach to it. This ordering allows
189 * debugging using the previous console, if any.
191 (*best_cp->cn_init)(best_cp);
192 if (cn_tab != NULL && cn_tab != best_cp) {
193 /* Turn off the previous console. */
194 if (cn_tab->cn_term != NULL)
195 (*cn_tab->cn_term)(cn_tab);
197 if (boothowto & RB_PAUSE)
203 * We can safely release the token after the init is done.
204 * Also assert that the mpcount is still correct or otherwise
205 * the SMP/AP boot will blow up on us.
207 lwkt_reltoken(&tty_token);
212 * Hook the open and close functions on the selected device.
217 if ((cn_tab == NULL) || cn_mute)
219 if (cn_tab->cn_dev == NULL) {
220 cn_tab->cn_init_fini(cn_tab);
221 if (cn_tab->cn_dev == NULL) {
222 kprintf("Unable to hook console! cn_tab %p\n", cn_tab);
227 cn_fwd_ops = dev_ops_intercept(cn_tab->cn_dev, &cn_iops);
228 cn_dev = cn_tab->cn_dev;
230 console_rdev = makeudev(cn_dev->si_umajor,
231 (cn_dev->si_uminor == 255 ?
232 0 : cn_dev->si_uminor));
245 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops);
252 * User has changed the state of the console muting.
253 * This may require us to open or close the device in question.
256 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
262 error = sysctl_handle_int(oidp, &cn_mute, 0, req);
263 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) {
264 if(ocn_mute && !cn_mute) {
266 * going from muted to unmuted.. open the physical dev
267 * if the console has been openned
271 /* XXX curproc is not what we want really */
272 error = dev_dopen(cn_dev, openflag,
273 openmode, curproc->p_ucred, NULL);
275 /* if it failed, back it out */
276 if ( error != 0) cnuninit();
277 } else if (!ocn_mute && cn_mute) {
279 * going from unmuted to muted.. close the physical dev
280 * if it's only open via /dev/console
283 error = dev_dclose(cn_dev, openflag,
291 * back out the change if there was an error
299 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
300 0, sizeof cn_mute, sysctl_kern_consmute, "I", "");
304 * We intercept the OPEN and CLOSE calls on the original device, and
305 * forward the rest through.
308 cnintercept(struct dev_generic_args *ap)
312 if (ap->a_desc == &dev_open_desc) {
313 error = cnopen((struct dev_open_args *)ap);
314 } else if (ap->a_desc == &dev_close_desc) {
315 error = cnclose((struct dev_close_args *)ap);
316 } else if (cn_fwd_ops) {
317 error = dev_doperate_ops(cn_fwd_ops, ap);
325 * cnopen() is called as an intercept function (dev will be that of the
326 * actual physical device representing our console), and also called from
327 * the muting code and from the /dev/console switch (dev will have the
331 cnopen(struct dev_open_args *ap)
333 cdev_t dev = ap->a_head.a_dev;
334 int flag = ap->a_oflags;
335 int mode = ap->a_devtype;
340 if (cn_tab == NULL || cn_fwd_ops == NULL)
343 cndev = cn_tab->cn_dev; /* actual physical device */
344 physdev = (dev == cn_devfsdev) ? cndev : dev;
347 * If mute is active, then non console opens don't get here
348 * so we don't need to check for that. They bypass this and go
349 * straight to the device.
351 * It is important to note that due to our intercept and the fact
352 * that we might be called via the original (intercepted) device,
353 * the original device's ops may point to us, so to avoid an
354 * infinite recursion we have to forward through cn_fwd_ops.
355 * This is a severe hack that really needs to be fixed XXX.
357 * XXX at the moment we assume that the port forwarding function
358 * is synchronous for open.
361 ap->a_head.a_dev = physdev;
362 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head);
366 * check if we openned it via /dev/console or
367 * via the physical entry (e.g. /dev/sio0).
371 } else if (physdev == cndev) {
376 dev->si_tty = cndev->si_tty;
382 * cnclose() is called as a port intercept function (dev will be that of the
383 * actual physical device representing our console), and also called from
384 * the muting code and from the /dev/console switch (dev will have the
388 cnclose(struct dev_close_args *ap)
393 cdev_t dev = ap->a_head.a_dev;
395 if (cn_tab == NULL || cn_fwd_ops == NULL)
397 cndev = cn_tab->cn_dev;
398 cn_tp = cndev->si_tty;
399 physdev = (dev == cn_devfsdev) ? cndev : dev;
402 * act appropriatly depending on whether it's /dev/console
403 * or the pysical device (e.g. /dev/sio) that's being closed.
404 * in either case, don't actually close the device unless
408 /* the physical device is about to be closed */
412 /* perform a ttyhalfclose() */
413 /* reset session and proc group */
414 ttyclearsession(cn_tp);
418 } else if (physdev == cndev) {
419 /* the logical console is about to be closed */
426 ap->a_head.a_dev = dev;
427 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head));
433 * The following functions are dispatched solely from the /dev/console
434 * device. Their job is primarily to forward the request through.
435 * If the console is not attached to anything then write()'s are sunk
436 * to null and reads return 0 (mostly).
439 cnread(struct dev_read_args *ap)
441 if (cn_tab == NULL || cn_fwd_ops == NULL)
443 ap->a_head.a_dev = cn_tab->cn_dev;
444 return (dev_doperate(&ap->a_head));
448 cnwrite(struct dev_write_args *ap)
450 struct uio *uio = ap->a_uio;
453 if (cn_tab == NULL || cn_fwd_ops == NULL) {
454 uio->uio_resid = 0; /* dump the data */
458 dev = constty->t_dev;
460 dev = cn_tab->cn_dev;
462 ap->a_head.a_dev = dev;
463 return (dev_doperate(&ap->a_head));
467 cnioctl(struct dev_ioctl_args *ap)
471 if (cn_tab == NULL || cn_fwd_ops == NULL)
473 KKASSERT(curproc != NULL);
475 * Superuser can always use this to wrest control of console
476 * output from the "virtual" console.
478 if (ap->a_cmd == TIOCCONS && constty) {
480 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
487 ap->a_head.a_dev = cn_tab->cn_dev;
488 return (dev_doperate(&ap->a_head));
492 cnkqfilter(struct dev_kqfilter_args *ap)
494 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL)
496 ap->a_head.a_dev = cn_tab->cn_dev;
497 return (dev_doperate(&ap->a_head));
501 * These synchronous functions are primarily used the kernel needs to
502 * access the keyboard (e.g. when running the debugger), or output data
503 * directly to the console.
509 if ((cn_tab == NULL) || cn_mute)
511 c = (*cn_tab->cn_getc)(cn_tab->cn_private);
512 if (c == '\r') c = '\n'; /* console input is always ICRNL */
519 if ((cn_tab == NULL) || cn_mute)
521 return ((*cn_tab->cn_checkc)(cn_tab->cn_private));
527 if ((cn_tab == NULL) || cn_mute)
530 ((*cn_tab->cn_poll)(cn_tab->cn_private, on));
538 if ((cn_tab == NULL) || cn_mute)
542 (*cn_tab->cn_putc)(cn_tab->cn_private, '\r');
543 (*cn_tab->cn_putc)(cn_tab->cn_private, c);
545 if (console_pausing && !db_active && (c == '\n')) {
547 if (console_pausing && (c == '\n')) {
549 for(cp=console_pausestr; *cp != '\0'; cp++)
550 (*cn_tab->cn_putc)(cn_tab->cn_private, *cp);
553 (*cn_tab->cn_putc)(cn_tab->cn_private, '\r');
554 for(cp=console_pausestr; *cp != '\0'; cp++)
555 (*cn_tab->cn_putc)(cn_tab->cn_private, ' ');
556 (*cn_tab->cn_putc)(cn_tab->cn_private, '\r');
570 if (refcount == 0 && cn_tab->cn_dbctl != NULL)
571 (*cn_tab->cn_dbctl)(cn_tab->cn_private, on);
577 cn_drvinit(void *unused)
579 cn_devfsdev = make_only_devfs_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL,
583 SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR, cn_drvinit, NULL);