xref: /dragonfly/stand/boot/common/boot.c (revision 22cd51fe)
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 
383