boot.c revision 193192
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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/boot/common/boot.c 193192 2009-06-01 01:02:30Z rodrigc $");
29
30/*
31 * Loading modules, booting the system
32 */
33
34#include <stand.h>
35#include <string.h>
36
37#include "bootstrap.h"
38
39static char	*getbootfile(int try);
40static int	loadakernel(int try, int argc, char* argv[]);
41
42/* List of kernel names to try (may be overwritten by boot.config) XXX should move from here? */
43static const char *default_bootfiles = "kernel";
44
45static int autoboot_tried;
46
47/*
48 * The user wants us to boot.
49 */
50COMMAND_SET(boot, "boot", "boot a file or loaded kernel", command_boot);
51
52static int
53command_boot(int argc, char *argv[])
54{
55    struct preloaded_file	*fp;
56
57    /*
58     * See if the user has specified an explicit kernel to boot.
59     */
60    if ((argc > 1) && (argv[1][0] != '-')) {
61
62	/* XXX maybe we should discard everything and start again? */
63	if (file_findfile(NULL, NULL) != NULL) {
64	    sprintf(command_errbuf, "can't boot '%s', kernel module already loaded", argv[1]);
65	    return(CMD_ERROR);
66	}
67
68	/* find/load the kernel module */
69	if (mod_loadkld(argv[1], argc - 2, argv + 2) != 0)
70	    return(CMD_ERROR);
71	/* we have consumed all arguments */
72	argc = 1;
73    }
74
75    /*
76     * See if there is a kernel module already loaded
77     */
78    if (file_findfile(NULL, NULL) == NULL)
79	if (loadakernel(0, argc - 1, argv + 1))
80	    /* we have consumed all arguments */
81	    argc = 1;
82
83    /*
84     * Loaded anything yet?
85     */
86    if ((fp = file_findfile(NULL, NULL)) == NULL) {
87	command_errmsg = "no bootable kernel";
88	return(CMD_ERROR);
89    }
90
91    /*
92     * If we were given arguments, discard any previous.
93     * XXX should we merge arguments?  Hard to DWIM.
94     */
95    if (argc > 1) {
96	if (fp->f_args != NULL)
97	    free(fp->f_args);
98	fp->f_args = unargv(argc - 1, argv + 1);
99    }
100
101    /* Hook for platform-specific autoloading of modules */
102    if (archsw.arch_autoload() != 0)
103	return(CMD_ERROR);
104
105    /* Call the exec handler from the loader matching the kernel */
106    file_formats[fp->f_loader]->l_exec(fp);
107    return(CMD_ERROR);
108}
109
110
111/*
112 * Autoboot after a delay
113 */
114
115COMMAND_SET(autoboot, "autoboot", "boot automatically after a delay", command_autoboot);
116
117static int
118command_autoboot(int argc, char *argv[])
119{
120    int		howlong;
121    char	*cp, *prompt;
122
123    prompt = NULL;
124    howlong = -1;
125    switch(argc) {
126    case 3:
127	prompt = argv[2];
128	/* FALLTHROUGH */
129    case 2:
130	howlong = strtol(argv[1], &cp, 0);
131	if (*cp != 0) {
132	    sprintf(command_errbuf, "bad delay '%s'", argv[1]);
133	    return(CMD_ERROR);
134	}
135	/* FALLTHROUGH */
136    case 1:
137	return(autoboot(howlong, prompt));
138    }
139
140    command_errmsg = "too many arguments";
141    return(CMD_ERROR);
142}
143
144/*
145 * Called before we go interactive.  If we think we can autoboot, and
146 * we haven't tried already, try now.
147 */
148void
149autoboot_maybe()
150{
151    char	*cp;
152
153    cp = getenv("autoboot_delay");
154    if ((autoboot_tried == 0) && ((cp == NULL) || strcasecmp(cp, "NO")))
155	autoboot(-1, NULL);		/* try to boot automatically */
156}
157
158int
159autoboot(int timeout, char *prompt)
160{
161    time_t	when, otime, ntime;
162    int		c, yes;
163    char	*argv[2], *cp, *ep;
164    char	*kernelname;
165
166    autoboot_tried = 1;
167
168    if (timeout == -1) {
169        timeout = 10;
170	/* try to get a delay from the environment */
171	if ((cp = getenv("autoboot_delay"))) {
172	    timeout = strtol(cp, &ep, 0);
173	    if (cp == ep)
174		timeout = 10;		/* Unparseable? Set default! */
175	}
176    }
177
178    kernelname = getenv("kernelname");
179    if (kernelname == NULL) {
180	argv[0] = NULL;
181	loadakernel(0, 0, argv);
182	kernelname = getenv("kernelname");
183	if (kernelname == NULL) {
184	    command_errmsg = "no valid kernel found";
185	    return(CMD_ERROR);
186	}
187    }
188
189    if (timeout >= 0) {
190        otime = time(NULL);
191        when = otime + timeout;	/* when to boot */
192
193        yes = 0;
194
195        printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
196
197        for (;;) {
198	    if (ischar()) {
199	        c = getchar();
200	        if ((c == '\r') || (c == '\n'))
201		    yes = 1;
202	        break;
203	    }
204	    ntime = time(NULL);
205	    if (ntime >= when) {
206	        yes = 1;
207	        break;
208	    }
209
210	    if (ntime != otime) {
211	        printf("\rBooting [%s] in %d second%s... ",
212	    		    kernelname, (int)(when - ntime),
213			    (when-ntime)==1?"":"s");
214	        otime = ntime;
215	    }
216        }
217    } else {
218        yes = 1;
219    }
220
221    if (yes)
222	printf("\rBooting [%s]...               ", kernelname);
223    putchar('\n');
224    if (yes) {
225	argv[0] = "boot";
226	argv[1] = NULL;
227	return(command_boot(1, argv));
228    }
229    return(CMD_OK);
230}
231
232/*
233 * Scrounge for the name of the (try)'th file we will try to boot.
234 */
235static char *
236getbootfile(int try)
237{
238    static char *name = NULL;
239    const char	*spec, *ep;
240    size_t	len;
241
242    /* we use dynamic storage */
243    if (name != NULL) {
244	free(name);
245	name = NULL;
246    }
247
248    /*
249     * Try $bootfile, then try our builtin default
250     */
251    if ((spec = getenv("bootfile")) == NULL)
252	spec = default_bootfiles;
253
254    while ((try > 0) && (spec != NULL)) {
255	spec = strchr(spec, ';');
256	if (spec)
257	    spec++;	/* skip over the leading ';' */
258	try--;
259    }
260    if (spec != NULL) {
261	if ((ep = strchr(spec, ';')) != NULL) {
262	    len = ep - spec;
263	} else {
264	    len = strlen(spec);
265	}
266	name = malloc(len + 1);
267	strncpy(name, spec, len);
268	name[len] = 0;
269    }
270    if (name && name[0] == 0) {
271	free(name);
272	name = NULL;
273    }
274    return(name);
275}
276
277/*
278 * Try to find the /etc/fstab file on the filesystem (rootdev),
279 * which should be be the root filesystem, and parse it to find
280 * out what the kernel ought to think the root filesystem is.
281 *
282 * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
283 * so that the kernel can tell both which VFS and which node to use
284 * to mount the device.  If this variable's already set, don't
285 * overwrite it.
286 */
287int
288getrootmount(char *rootdev)
289{
290    char	lbuf[128], *cp, *ep, *dev, *fstyp, *options;
291    int		fd, error;
292
293    if (getenv("vfs.root.mountfrom") != NULL)
294	return(0);
295
296    sprintf(lbuf, "%s/etc/fstab", rootdev);
297    if ((fd = open(lbuf, O_RDONLY)) < 0)
298	return(1);
299
300    /* loop reading lines from /etc/fstab    What was that about sscanf again? */
301    error = 1;
302    while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
303	if ((lbuf[0] == 0) || (lbuf[0] == '#'))
304	    continue;
305
306	/* skip device name */
307	for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
308	    ;
309	if (*cp == 0)		/* misformatted */
310	    continue;
311	/* delimit and save */
312	*cp++ = 0;
313	dev = strdup(lbuf);
314
315	/* skip whitespace up to mountpoint */
316	while ((*cp != 0) && isspace(*cp))
317	    cp++;
318	/* must have /<space> to be root */
319	if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
320	    continue;
321	/* skip whitespace up to fstype */
322	cp += 2;
323	while ((*cp != 0) && isspace(*cp))
324	    cp++;
325	if (*cp == 0)		/* misformatted */
326	    continue;
327	/* skip text to end of fstype and delimit */
328	ep = cp;
329	while ((*cp != 0) && !isspace(*cp))
330	    cp++;
331	*cp = 0;
332	fstyp = strdup(ep);
333
334	/* skip whitespace up to mount options */
335	cp += 1;
336	while ((*cp != 0) && isspace(*cp))
337		cp++;
338	if (*cp == 0)           /* misformatted */
339		continue;
340	/* skip text to end of mount options and delimit */
341	ep = cp;
342	while ((*cp != 0) && !isspace(*cp))
343		cp++;
344	*cp = 0;
345	options = strdup(ep);
346	/* Build the <fstype>:<device> and save it in vfs.root.mountfrom */
347	sprintf(lbuf, "%s:%s", fstyp, dev);
348	free(dev);
349	free(fstyp);
350	setenv("vfs.root.mountfrom", lbuf, 0);
351
352	/* Don't override vfs.root.mountfrom.options if it is already set */
353	if (getenv("vfs.root.mountfrom.options") == NULL) {
354		/* save mount options */
355		setenv("vfs.root.mountfrom.options", options, 0);
356	}
357	free(options);
358	error = 0;
359	break;
360    }
361    close(fd);
362    return(error);
363}
364
365static int
366loadakernel(int try, int argc, char* argv[])
367{
368    char *cp;
369
370	for (try = 0; (cp = getbootfile(try)) != NULL; try++)
371	    if (mod_loadkld(cp, argc - 1, argv + 1) != 0)
372		printf("can't load '%s'\n", cp);
373	    else
374		return 1;
375	return 0;
376}
377