sys/boot/common/boot.c

   1 /*-
   2  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
   3  * 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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/boot/common/boot.c,v 1.29 2003/08/25 23:30:41 obrien Exp $
  27  */
  28
  29 /*
  30  * Loading modules, booting the system
  31  */
  32
  33 #include <stand.h>
  34 #include <string.h>
  35
  36 #include "bootstrap.h"
  37
  38 static char     *getbootfile(int try);
  39 static int      loadakernel(int try, int argc, char* argv[]);
  40
  41 /* List of kernel names to try (may be overwritten by boot.config) XXX should move from here? */
  42 static const char *default_bootfiles = "kernel";
  43
  44 static int autoboot_tried;
  45
  46 /*
  47  * The user wants us to boot.
  48  */
  49 COMMAND_SET(boot, "boot", "boot a file or loaded kernel", command_boot);
  50
  51 static int
  52 command_boot(int argc, char *argv[])
  53 {
  54     struct preloaded_file       *fp;
  55     char *local_module_path;
  56     char *exported_module_path;
  57
  58     /*
  59      * See if the user has specified an explicit kernel to boot.
  60      */
  61     if ((argc > 1) && (argv[1][0] != '-')) {
  62
  63         /* XXX maybe we should discard everything and start again? */
  64         if (file_findfile(NULL, NULL) != NULL) {
  65             snprintf(command_errbuf, sizeof(command_errbuf),
  66                 "can't boot '%s', kernel module already loaded", argv[1]);
  67             return(CMD_ERROR);
  68         }
  69
  70         /* find/load the kernel module */
  71         if (mod_loadkld(argv[1], argc - 2, argv + 2) != 0)
  72             return(CMD_ERROR);
  73         /* we have consumed all arguments */
  74         argc = 1;
  75     }
  76
  77     /*
  78      * See if there is a kernel module already loaded
  79      */
  80     if (file_findfile(NULL, NULL) == NULL)
  81         if (loadakernel(0, argc - 1, argv + 1))
  82             /* we have consumed all arguments */
  83             argc = 1;
  84
  85     /*
  86      * Loaded anything yet?
  87      */
  88     if ((fp = file_findfile(NULL, NULL)) == NULL) {
  89         command_errmsg = "no bootable kernel";
  90         return(CMD_ERROR);
  91     }
  92
  93     /*
  94      * If we were given arguments, discard any previous.
  95      * XXX should we merge arguments?  Hard to DWIM.
  96      */
  97     if (argc > 1) {
  98         if (fp->f_args != NULL)
  99             free(fp->f_args);
 100         fp->f_args = unargv(argc - 1, argv + 1);
 101     }
 102
 103     /* Hook for platform-specific autoloading of modules */
 104     if (archsw.arch_autoload() != 0)
 105         return(CMD_ERROR);
 106
 107     /*
 108      * Exec the kernel.  We have to shift our exported_module_path
 109      * (which has the correct /boot prefix for the kernel) over to
 110      * module_path.  If the exec fails we switch it back.
 111      */
 112     exported_module_path = getenv("exported_module_path");
 113     if (exported_module_path) {
 114             exported_module_path = strdup(exported_module_path);
 115             local_module_path = getenv("module_path");
 116             if (local_module_path)
 117                 local_module_path = strdup(local_module_path);
 118             setenv("module_path", exported_module_path, 1);
 119             unsetenv("exported_module_path");
 120     }
 121
 122     /* Call the exec handler from the loader matching the kernel */
 123     file_formats[fp->f_loader]->l_exec(fp);
 124
 125     if (exported_module_path) {
 126             if (local_module_path) {
 127                 setenv("module_path", local_module_path, 1);
 128                 free(local_module_path);
 129             } else {
 130                 unsetenv("module_path");
 131             }
 132             setenv("exported_module_path", exported_module_path, 1);
 133             free(exported_module_path);
 134     }
 135     return(CMD_ERROR);
 136 }
 137
 138
 139 /*
 140  * Autoboot after a delay
 141  */
 142
 143 COMMAND_SET(autoboot, "autoboot", "boot automatically after a delay", command_autoboot);
 144
 145 static int
 146 command_autoboot(int argc, char *argv[])
 147 {
 148     int         howlong;
 149     char        *cp, *prompt;
 150
 151     prompt = NULL;
 152     howlong = -1;
 153     switch(argc) {
 154     case 3:
 155         prompt = argv[2];
 156         /* FALLTHROUGH */
 157     case 2:
 158         howlong = strtol(argv[1], &cp, 0);
 159         if (*cp != 0) {
 160             snprintf(command_errbuf, sizeof(command_errbuf),
 161                 "bad delay '%s'", argv[1]);
 162             return(CMD_ERROR);
 163         }
 164         /* FALLTHROUGH */
 165     case 1:
 166         return(autoboot(howlong, prompt));
 167     }
 168
 169     command_errmsg = "too many arguments";
 170     return(CMD_ERROR);
 171 }
 172
 173 /*
 174  * Called before we go interactive.  If we think we can autoboot, and
 175  * we haven't tried already, try now.
 176  */
 177 void
 178 autoboot_maybe(void)
 179 {
 180     char        *cp;
 181
 182     cp = getenv("autoboot_delay");
 183     if ((autoboot_tried == 0) && ((cp == NULL) || strcasecmp(cp, "NO")))
 184         autoboot(-1, NULL);             /* try to boot automatically */
 185 }
 186
 187 int
 188 autoboot(int timeout, char *prompt)
 189 {
 190     time_t      when, otime, ntime;
 191     int         c, yes;
 192     char        *argv[2], *cp, *ep;
 193     char        *kernelname;
 194
 195     autoboot_tried = 1;
 196
 197     if (timeout == -1) {
 198         /* try to get a delay from the environment */
 199         if ((cp = getenv("autoboot_delay"))) {
 200             timeout = strtol(cp, &ep, 0);
 201             if (cp == ep)
 202                 timeout = -1;
 203         }
 204     }
 205     if (timeout == -1)          /* all else fails */
 206         timeout = 10;
 207
 208     kernelname = getenv("kernelname");
 209     if (kernelname == NULL) {
 210         argv[0] = NULL;
 211         loadakernel(0, 0, argv);
 212         kernelname = getenv("kernelname");
 213         if (kernelname == NULL) {
 214             command_errmsg = "no valid kernel found";
 215             return(CMD_ERROR);
 216         }
 217     }
 218
 219     otime = time(NULL);
 220     when = otime + timeout;     /* when to boot */
 221     yes = 0;
 222
 223     printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
 224
 225     for (;;) {
 226         if (ischar()) {
 227             c = getchar();
 228             if ((c == '\r') || (c == '\n'))
 229                 yes = 1;
 230             break;
 231         }
 232         ntime = time(NULL);
 233         if (ntime >= when) {
 234             yes = 1;
 235             break;
 236         }
 237
 238         if (ntime != otime) {
 239             printf("\rBooting [%s] in %d second%s... ",
 240                         kernelname, (int)(when - ntime),
 241                         (when-ntime)==1?"":"s");
 242             otime = ntime;
 243         }
 244     }
 245     if (yes)
 246         printf("\rBooting [%s]...               ", kernelname);
 247     putchar('\n');
 248     if (yes) {
 249         argv[0] = "boot";
 250         argv[1] = NULL;
 251         return(command_boot(1, argv));
 252     }
 253     return(CMD_OK);
 254 }
 255
 256 /*
 257  * Scrounge for the name of the (try)'th file we will try to boot.
 258  */
 259 static char *
 260 getbootfile(int try)
 261 {
 262     static char *name = NULL;
 263     const char  *spec, *ep;
 264     size_t      len;
 265
 266     /* we use dynamic storage */
 267     if (name != NULL) {
 268         free(name);
 269         name = NULL;
 270     }
 271
 272     /*
 273      * Try $bootfile, then try our builtin default
 274      */
 275     if ((spec = getenv("bootfile")) == NULL)
 276         spec = default_bootfiles;
 277
 278     while ((try > 0) && (spec != NULL)) {
 279         spec = strchr(spec, ';');
 280         if (spec)
 281             spec++;     /* skip over the leading ';' */
 282         try--;
 283     }
 284     if (spec != NULL) {
 285         if ((ep = strchr(spec, ';')) != NULL) {
 286             len = ep - spec;
 287         } else {
 288             len = strlen(spec);
 289         }
 290         name = malloc(len + 1);
 291         strncpy(name, spec, len);
 292         name[len] = 0;
 293     }
 294     if (name && name[0] == 0) {
 295         free(name);
 296         name = NULL;
 297     }
 298     return(name);
 299 }
 300
 301 /*
 302  * Try to find the /etc/fstab file on the filesystem (rootdev),
 303  * which should be be the root filesystem, and parse it to find
 304  * out what the kernel ought to think the root filesystem is.
 305  *
 306  * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
 307  * so that the kernel can tell both which VFS and which node to use
 308  * to mount the device.  If this variable's already set, don't
 309  * overwrite it.
 310  */
 311 int
 312 getrootmount(char *rootdev)
 313 {
 314     char        lbuf[128], *cp, *ep, *dev, *fstyp;
 315     int         fd, error;
 316
 317     if (getenv("vfs.root.mountfrom") != NULL)
 318         return(0);
 319
 320     sprintf(lbuf, "%s/etc/fstab", rootdev);
 321     if ((fd = open(lbuf, O_RDONLY)) < 0)
 322         return(1);
 323
 324     /* loop reading lines from /etc/fstab    What was that about sscanf again? */
 325     error = 1;
 326     while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
 327         if ((lbuf[0] == 0) || (lbuf[0] == '#'))
 328             continue;
 329
 330         /* skip device name */
 331         for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
 332             ;
 333         if (*cp == 0)           /* misformatted */
 334             continue;
 335         /* delimit and save */
 336         *cp++ = 0;
 337         dev = strdup(lbuf);
 338
 339         /* skip whitespace up to mountpoint */
 340         while ((*cp != 0) && isspace(*cp))
 341             cp++;
 342         /* must have /<space> to be root */
 343         if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
 344             continue;
 345         /* skip whitespace up to fstype */
 346         cp += 2;
 347         while ((*cp != 0) && isspace(*cp))
 348             cp++;
 349         if (*cp == 0)           /* misformatted */
 350             continue;
 351         /* skip text to end of fstype and delimit */
 352         ep = cp;
 353         while ((*cp != 0) && !isspace(*cp))
 354             cp++;
 355         *cp = 0;
 356         fstyp = strdup(ep);
 357
 358         /* build the final result and save it */
 359         sprintf(lbuf, "%s:%s", fstyp, dev);
 360         free(dev);
 361         free(fstyp);
 362         setenv("vfs.root.mountfrom", lbuf, 0);
 363         error = 0;
 364         break;
 365     }
 366     close(fd);
 367     return(error);
 368 }
 369
 370 static int
 371 loadakernel(int try, int argc, char* argv[])
 372 {
 373     char *cp;
 374
 375         for (try = 0; (cp = getbootfile(try)) != NULL; try++)
 376             if (mod_loadkld(cp, argc - 1, argv + 1) != 0)
 377                 printf("can't load '%s'\n", cp);
 378             else
 379                 return 1;
 380         return 0;
 381 }
 382