boot.c revision 64187 
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: head/sys/boot/common/boot.c 64187 2000-08-03 09:14:02Z jhb $
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
38static char	*getbootfile(int try);
39
40/* List of kernel names to try (may be overwritten by boot.config) XXX should move from here? */
41static const char *default_bootfiles = "kernel;kernel.old";
42
43static int autoboot_tried;
44
45/*
46 * The user wants us to boot.
47 */
48COMMAND_SET(boot, "boot", "boot a file or loaded kernel", command_boot);
49
50static int
51command_boot(int argc, char *argv[])
52{
53    struct preloaded_file	*fp;
54    char			*cp;
55    int				try;
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_load(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	for (try = 0; (cp = getbootfile(try)) != NULL; try++) {
80	    if (mod_load(cp, argc - 1, argv + 1) != 0) {
81		printf("can't load '%s'\n", cp);
82	    } else {
83		/* we have consumed all arguments */
84		argc = 1;
85		break;
86	    }
87	}
88    }
89
90    /*
91     * Loaded anything yet?
92     */
93    if ((fp = file_findfile(NULL, NULL)) == NULL) {
94	command_errmsg = "no bootable kernel";
95	return(CMD_ERROR);
96    }
97
98    /*
99     * If we were given arguments, discard any previous.
100     * XXX should we merge arguments?  Hard to DWIM.
101     */
102    if (argc > 1) {
103	if (fp->f_args != NULL)
104	    free(fp->f_args);
105	fp->f_args = unargv(argc - 1, argv + 1);
106    }
107
108    /* Hook for platform-specific autoloading of modules */
109    if (archsw.arch_autoload() != 0)
110	return(CMD_ERROR);
111
112    /* Call the exec handler from the loader matching the kernel */
113    file_formats[fp->f_loader]->l_exec(fp);
114    return(CMD_ERROR);
115}
116
117
118/*
119 * Autoboot after a delay
120 */
121
122COMMAND_SET(autoboot, "autoboot", "boot automatically after a delay", command_autoboot);
123
124static int
125command_autoboot(int argc, char *argv[])
126{
127    int		howlong;
128    char	*cp, *prompt;
129
130    prompt = NULL;
131    howlong = -1;
132    switch(argc) {
133    case 3:
134	prompt = argv[2];
135	/* FALLTHROUGH */
136    case 2:
137	howlong = strtol(argv[1], &cp, 0);
138	if (*cp != 0) {
139	    sprintf(command_errbuf, "bad delay '%s'", argv[1]);
140	    return(CMD_ERROR);
141	}
142	/* FALLTHROUGH */
143    case 1:
144	return(autoboot(howlong, prompt));
145    }
146
147    command_errmsg = "too many arguments";
148    return(CMD_ERROR);
149}
150
151/*
152 * Called before we go interactive.  If we think we can autoboot, and
153 * we haven't tried already, try now.
154 */
155void
156autoboot_maybe()
157{
158    char	*cp;
159
160    cp = getenv("autoboot_delay");
161    if ((autoboot_tried == 0) && ((cp == NULL) || strcasecmp(cp, "NO")))
162	autoboot(-1, NULL);		/* try to boot automatically */
163}
164
165int
166autoboot(int timeout, char *prompt)
167{
168    time_t	when, otime, ntime;
169    int		c, yes;
170    char	*argv[2], *cp, *ep;
171
172    autoboot_tried = 1;
173
174    if (timeout == -1) {
175	/* try to get a delay from the environment */
176	if ((cp = getenv("autoboot_delay"))) {
177	    timeout = strtol(cp, &ep, 0);
178	    if (cp == ep)
179		timeout = -1;
180	}
181    }
182    if (timeout == -1)		/* all else fails */
183	timeout = 10;
184
185    otime = time(NULL);
186    when = otime + timeout;	/* when to boot */
187    yes = 0;
188
189    /* XXX could try to work out what we might boot */
190    printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
191
192    for (;;) {
193	if (ischar()) {
194	    c = getchar();
195	    if ((c == '\r') || (c == '\n'))
196		yes = 1;
197	    break;
198	}
199	ntime = time(NULL);
200	if (ntime >= when) {
201	    yes = 1;
202	    break;
203	}
204	if (ntime != otime) {
205	    printf("\rBooting [%s] in %d second%s... ",
206	    		getbootfile(0), (int)(when - ntime),
207			(when-ntime)==1?"":"s");
208	    otime = ntime;
209	}
210    }
211    if (yes)
212	printf("\rBooting [%s]...               ", getbootfile(0));
213    putchar('\n');
214    if (yes) {
215	argv[0] = "boot";
216	argv[1] = NULL;
217	return(command_boot(1, argv));
218    }
219    return(CMD_OK);
220}
221
222/*
223 * Scrounge for the name of the (try)'th file we will try to boot.
224 */
225static char *
226getbootfile(int try)
227{
228    static char *name = NULL;
229    char	*spec, *ep;
230    size_t	len;
231
232    /* we use dynamic storage */
233    if (name != NULL) {
234	free(name);
235	name = NULL;
236    }
237
238    /*
239     * Try $bootfile, then try our builtin default
240     */
241    if ((spec = getenv("bootfile")) == NULL)
242	spec = default_bootfiles;
243
244    while ((try > 0) && (spec != NULL)) {
245	spec = strchr(spec, ';');
246	if (spec)
247	    spec++;	/* skip over the leading ';' */
248	try--;
249    }
250    if (spec != NULL) {
251	if ((ep = strchr(spec, ';')) != NULL) {
252	    len = ep - spec;
253	} else {
254	    len = strlen(spec);
255	}
256	name = malloc(len + 1);
257	strncpy(name, spec, len);
258	name[len] = 0;
259    }
260    if (name[0] == 0) {
261	free(name);
262	name = NULL;
263    }
264    return(name);
265}
266
267/*
268 * Try to find the /etc/fstab file on the filesystem (rootdev),
269 * which should be be the root filesystem, and parse it to find
270 * out what the kernel ought to think the root filesystem is.
271 *
272 * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
273 * so that the kernel can tell both which VFS and which node to use
274 * to mount the device.  If this variable's already set, don't
275 * overwrite it.
276 */
277int
278getrootmount(char *rootdev)
279{
280    char	lbuf[128], *cp, *ep, *dev, *fstyp;
281    int		fd, error;
282
283    if (getenv("vfs.root.mountfrom") != NULL)
284	return(0);
285
286    sprintf(lbuf, "%s/etc/fstab", rootdev);
287    if ((fd = open(lbuf, O_RDONLY)) < 0)
288	return(1);
289
290    /* loop reading lines from /etc/fstab    What was that about sscanf again? */
291    error = 1;
292    while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
293	if ((lbuf[0] == 0) || (lbuf[0] == '#'))
294	    continue;
295
296	/* skip device name */
297	for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
298	    ;
299	if (*cp == 0)		/* misformatted */
300	    continue;
301	/* delimit and save */
302	*cp++ = 0;
303	dev = strdup(lbuf);
304
305	/* skip whitespace up to mountpoint */
306	while ((*cp != 0) && isspace(*cp))
307	    cp++;
308	/* must have /<space> to be root */
309	if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
310	    continue;
311	/* skip whitespace up to fstype */
312	cp += 2;
313	while ((*cp != 0) && isspace(*cp))
314	    cp++;
315	if (*cp == 0)		/* misformatted */
316	    continue;
317	/* skip text to end of fstype and delimit */
318	ep = cp;
319	while ((*cp != 0) && !isspace(*cp))
320	    cp++;
321	*cp = 0;
322	fstyp = strdup(ep);
323
324	/* build the final result and save it */
325	sprintf(lbuf, "%s:%s", fstyp, dev);
326	free(dev);
327	free(fstyp);
328	setenv("vfs.root.mountfrom", lbuf, 0);
329	error = 0;
330	break;
331    }
332    close(fd);
333    return(error);
334}
335