kern_cons.c revision 14846
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 1.42 1996/03/27 18:55:19 bde 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/sysctl.h> 50#include <sys/proc.h> 51#include <sys/tty.h> 52 53#include <machine/cpu.h> 54#include <machine/cons.h> 55#include <machine/stdarg.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 87struct tty *constty = 0; /* virtual console output device */ 88 89static dev_t cn_dev_t; 90SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLTYPE_OPAQUE|CTLFLAG_RD, 91 &cn_dev_t, sizeof cn_dev_t, "T,dev_t", ""); 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 * If no console, give up. 126 */ 127 if (best_cp == NULL) { 128 cn_tab = best_cp; 129 return; 130 } 131 132 /* 133 * Initialize console, then attach to it. This ordering allows 134 * debugging using the previous console, if any. 135 * XXX if there was a previous console, then its driver should 136 * be informed when we forget about it. 137 */ 138 (*best_cp->cn_init)(best_cp); 139 cn_tab = best_cp; 140} 141 142void 143cninit_finish() 144{ 145 struct cdevsw *cdp; 146 147 if (cn_tab == NULL) 148 return; 149 150 /* 151 * Hook the open and close functions. 152 */ 153 cdp = cdevsw[major(cn_tab->cn_dev)]; 154 cn_phys_close = cdp->d_close; 155 cdp->d_close = cnclose; 156 cn_phys_open = cdp->d_open; 157 cdp->d_open = cnopen; 158 cn_tp = (*cdp->d_devtotty)(cn_tab->cn_dev); 159 cn_dev_t = cn_tp->t_dev; 160} 161 162static int 163cnopen(dev, flag, mode, p) 164 dev_t dev; 165 int flag, mode; 166 struct proc *p; 167{ 168 dev_t cndev, physdev; 169 int retval; 170 171 if (cn_tab == NULL) 172 return (0); 173 cndev = cn_tab->cn_dev; 174 physdev = (major(dev) == major(cndev) ? dev : cndev); 175 retval = (*cn_phys_open)(physdev, flag, mode, p); 176 if (retval == 0) { 177 if (dev == cndev) 178 cn_phys_is_open = 1; 179 else if (physdev == cndev) 180 cn_is_open = 1; 181 } 182 return (retval); 183} 184 185static int 186cnclose(dev, flag, mode, p) 187 dev_t dev; 188 int flag, mode; 189 struct proc *p; 190{ 191 dev_t cndev; 192 193 if (cn_tab == NULL) 194 return (0); 195 cndev = cn_tab->cn_dev; 196 if (dev == cndev) { 197 /* the physical device is about to be closed */ 198 cn_phys_is_open = 0; 199 if (cn_is_open) { 200 if (cn_tp) { 201 /* perform a ttyhalfclose() */ 202 /* reset session and proc group */ 203 cn_tp->t_pgrp = NULL; 204 cn_tp->t_session = NULL; 205 } 206 return (0); 207 } 208 } else if (major(dev) != major(cndev)) { 209 /* the logical console is about to be closed */ 210 cn_is_open = 0; 211 if (cn_phys_is_open) 212 return (0); 213 dev = cndev; 214 } 215 return ((*cn_phys_close)(dev, flag, mode, p)); 216} 217 218static int 219cnread(dev, uio, flag) 220 dev_t dev; 221 struct uio *uio; 222 int flag; 223{ 224 if (cn_tab == NULL) 225 return (0); 226 dev = cn_tab->cn_dev; 227 return ((*cdevsw[major(dev)]->d_read)(dev, uio, flag)); 228} 229 230static int 231cnwrite(dev, uio, flag) 232 dev_t dev; 233 struct uio *uio; 234 int flag; 235{ 236 if (cn_tab == NULL) 237 return (0); 238 if (constty) 239 dev = constty->t_dev; 240 else 241 dev = cn_tab->cn_dev; 242 return ((*cdevsw[major(dev)]->d_write)(dev, uio, flag)); 243} 244 245static int 246cnioctl(dev, cmd, data, flag, p) 247 dev_t dev; 248 int cmd; 249 caddr_t data; 250 int flag; 251 struct proc *p; 252{ 253 int error; 254 255 if (cn_tab == NULL) 256 return (0); 257 /* 258 * Superuser can always use this to wrest control of console 259 * output from the "virtual" console. 260 */ 261 if (cmd == TIOCCONS && constty) { 262 error = suser(p->p_ucred, (u_short *) NULL); 263 if (error) 264 return (error); 265 constty = NULL; 266 return (0); 267 } 268 dev = cn_tab->cn_dev; 269 return ((*cdevsw[major(dev)]->d_ioctl)(dev, cmd, data, flag, p)); 270} 271 272static int 273cnselect(dev, rw, p) 274 dev_t dev; 275 int rw; 276 struct proc *p; 277{ 278 if (cn_tab == NULL) 279 return (1); 280 281 dev = cn_tab->cn_dev; 282 283 return ((*cdevsw[major(dev)]->d_select)(dev, rw, p)); 284} 285 286int 287cngetc() 288{ 289 int c; 290 if (cn_tab == NULL) 291 return (0); 292 c = (*cn_tab->cn_getc)(cn_tab->cn_dev); 293 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 294 return (c); 295} 296 297int 298cncheckc() 299{ 300 if (cn_tab == NULL) 301 return (0); 302 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev)); 303} 304 305void 306cnputc(c) 307 register int c; 308{ 309 if (cn_tab == NULL) 310 return; 311 if (c) { 312 if (c == '\n') 313 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 314 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 315 } 316} 317 318static cn_devsw_installed = 0; 319 320static void 321cn_drvinit(void *unused) 322{ 323 dev_t dev; 324 325 if( ! cn_devsw_installed ) { 326 dev = makedev(CDEV_MAJOR,0); 327 cdevsw_add(&dev,&cn_cdevsw,NULL); 328 cn_devsw_installed = 1; 329#ifdef DEVFS 330 cn_devfs_token = devfs_add_devsw( 331 "/", 332 "console", 333 &cn_cdevsw, 334 0, 335 DV_CHR, 336 0, 337 0, 338 0640); 339#endif 340 } 341} 342 343SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 344 345 346