boot.c revision 335755 
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: stable/11/stand/common/boot.c 335755 2018-06-28 01:32:37Z kevans $");
29
30/*
31 * Loading modules, booting the system
32 */
33
34#include <stand.h>
35#include <sys/reboot.h>
36#include <sys/boot.h>
37#include <string.h>
38
39#include "bootstrap.h"
40
41static int	autoboot(int timeout, char *prompt);
42static char	*getbootfile(int try);
43static int	loadakernel(int try, int argc, char* argv[]);
44
45/* List of kernel names to try (may be overwritten by boot.config) XXX should move from here? */
46static const char *default_bootfiles = "kernel";
47
48static int autoboot_tried;
49
50/*
51 * The user wants us to boot.
52 */
53COMMAND_SET(boot, "boot", "boot a file or loaded kernel", command_boot);
54
55static int
56command_boot(int argc, char *argv[])
57{
58	struct preloaded_file	*fp;
59
60	/*
61	 * See if the user has specified an explicit kernel to boot.
62	 */
63	if ((argc > 1) && (argv[1][0] != '-')) {
64
65		/* XXX maybe we should discard everything and start again? */
66		if (file_findfile(NULL, NULL) != NULL) {
67			snprintf(command_errbuf, sizeof(command_errbuf),
68			    "can't boot '%s', kernel module already loaded", argv[1]);
69			return(CMD_ERROR);
70		}
71
72		/* find/load the kernel module */
73		if (mod_loadkld(argv[1], argc - 2, argv + 2) != 0)
74			return(CMD_ERROR);
75		/* we have consumed all arguments */
76		argc = 1;
77	}
78
79	/*
80	 * See if there is a kernel module already loaded
81	 */
82	if (file_findfile(NULL, NULL) == NULL)
83		if (loadakernel(0, argc - 1, argv + 1))
84			/* we have consumed all arguments */
85			argc = 1;
86
87	/*
88	 * Loaded anything yet?
89	 */
90	if ((fp = file_findfile(NULL, NULL)) == NULL) {
91		command_errmsg = "no bootable kernel";
92		return(CMD_ERROR);
93	}
94
95	/*
96	 * If we were given arguments, discard any previous.
97	 * XXX should we merge arguments?  Hard to DWIM.
98	 */
99	if (argc > 1) {
100		if (fp->f_args != NULL)
101			free(fp->f_args);
102		fp->f_args = unargv(argc - 1, argv + 1);
103	}
104
105	/* Hook for platform-specific autoloading of modules */
106	if (archsw.arch_autoload() != 0)
107		return(CMD_ERROR);
108
109	/* Call the exec handler from the loader matching the kernel */
110	file_formats[fp->f_loader]->l_exec(fp);
111	return(CMD_ERROR);
112}
113
114
115/*
116 * Autoboot after a delay
117 */
118
119COMMAND_SET(autoboot, "autoboot", "boot automatically after a delay", command_autoboot);
120
121static int
122command_autoboot(int argc, char *argv[])
123{
124	int		howlong;
125	char	*cp, *prompt;
126
127	prompt = NULL;
128	howlong = -1;
129	switch(argc) {
130	case 3:
131		prompt = argv[2];
132		/* FALLTHROUGH */
133	case 2:
134		howlong = strtol(argv[1], &cp, 0);
135		if (*cp != 0) {
136			snprintf(command_errbuf, sizeof(command_errbuf),
137			    "bad delay '%s'", argv[1]);
138			return(CMD_ERROR);
139		}
140		/* FALLTHROUGH */
141	case 1:
142		return(autoboot(howlong, prompt));
143	}
144
145	command_errmsg = "too many arguments";
146	return(CMD_ERROR);
147}
148
149/*
150 * Called before we go interactive.  If we think we can autoboot, and
151 * we haven't tried already, try now.
152 */
153void
154autoboot_maybe()
155{
156	char	*cp;
157
158	cp = getenv("autoboot_delay");
159	if ((autoboot_tried == 0) && ((cp == NULL) || strcasecmp(cp, "NO")))
160		autoboot(-1, NULL);		/* try to boot automatically */
161}
162
163int
164bootenv_flags()
165{
166	int i, howto;
167	char *val;
168
169	for (howto = 0, i = 0; howto_names[i].ev != NULL; i++) {
170		val = getenv(howto_names[i].ev);
171		if (val != NULL && strcasecmp(val, "no") != 0)
172			howto |= howto_names[i].mask;
173	}
174	return (howto);
175}
176
177void
178bootenv_set(int howto)
179{
180	int i;
181
182	for (i = 0; howto_names[i].ev != NULL; i++)
183		if (howto & howto_names[i].mask)
184			setenv(howto_names[i].ev, "YES", 1);
185}
186
187static int
188autoboot(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#ifdef BOOT_PROMPT_123
195	const char	*seq = "123", *p = seq;
196#endif
197
198	autoboot_tried = 1;
199
200	if (timeout == -1) {
201		timeout = 10;
202		/* try to get a delay from the environment */
203		if ((cp = getenv("autoboot_delay"))) {
204			timeout = strtol(cp, &ep, 0);
205			if (cp == ep)
206				timeout = 10;		/* Unparseable? Set default! */
207		}
208	}
209
210	kernelname = getenv("kernelname");
211	if (kernelname == NULL) {
212		argv[0] = NULL;
213		loadakernel(0, 0, argv);
214		kernelname = getenv("kernelname");
215		if (kernelname == NULL) {
216			command_errmsg = "no valid kernel found";
217			return(CMD_ERROR);
218		}
219	}
220
221	if (timeout >= 0) {
222		otime = time(NULL);
223		when = otime + timeout;	/* when to boot */
224
225		yes = 0;
226
227#ifdef BOOT_PROMPT_123
228		printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or "
229		    "1 2 3 sequence for command prompt." : prompt);
230#else
231		printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
232#endif
233
234		for (;;) {
235			if (ischar()) {
236				c = getchar();
237#ifdef BOOT_PROMPT_123
238				if ((c == '\r') || (c == '\n')) {
239					yes = 1;
240					break;
241				} else if (c != *p++)
242					p = seq;
243				if (*p == 0)
244					break;
245#else
246				if ((c == '\r') || (c == '\n'))
247					yes = 1;
248				break;
249#endif
250			}
251			ntime = time(NULL);
252			if (ntime >= when) {
253				yes = 1;
254				break;
255			}
256
257			if (ntime != otime) {
258				printf("\rBooting [%s] in %d second%s... ",
259				    kernelname, (int)(when - ntime),
260				    (when-ntime)==1?"":"s");
261				otime = ntime;
262			}
263		}
264	} else {
265		yes = 1;
266	}
267
268	if (yes)
269		printf("\rBooting [%s]...               ", kernelname);
270	putchar('\n');
271	if (yes) {
272		argv[0] = "boot";
273		argv[1] = NULL;
274		return(command_boot(1, argv));
275	}
276	return(CMD_OK);
277}
278
279/*
280 * Scrounge for the name of the (try)'th file we will try to boot.
281 */
282static char *
283getbootfile(int try)
284{
285	static char *name = NULL;
286	const char	*spec, *ep;
287	size_t	len;
288
289	/* we use dynamic storage */
290	if (name != NULL) {
291		free(name);
292		name = NULL;
293	}
294
295	/*
296	 * Try $bootfile, then try our builtin default
297	 */
298	if ((spec = getenv("bootfile")) == NULL)
299		spec = default_bootfiles;
300
301	while ((try > 0) && (spec != NULL)) {
302		spec = strchr(spec, ';');
303		if (spec)
304			spec++;	/* skip over the leading ';' */
305		try--;
306	}
307	if (spec != NULL) {
308		if ((ep = strchr(spec, ';')) != NULL) {
309			len = ep - spec;
310		} else {
311			len = strlen(spec);
312		}
313		name = malloc(len + 1);
314		strncpy(name, spec, len);
315		name[len] = 0;
316	}
317	if (name && name[0] == 0) {
318		free(name);
319		name = NULL;
320	}
321	return(name);
322}
323
324/*
325 * Try to find the /etc/fstab file on the filesystem (rootdev),
326 * which should be be the root filesystem, and parse it to find
327 * out what the kernel ought to think the root filesystem is.
328 *
329 * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
330 * so that the kernel can tell both which VFS and which node to use
331 * to mount the device.  If this variable's already set, don't
332 * overwrite it.
333 */
334int
335getrootmount(char *rootdev)
336{
337	char	lbuf[128], *cp, *ep, *dev, *fstyp, *options;
338	int		fd, error;
339
340	if (getenv("vfs.root.mountfrom") != NULL)
341		return(0);
342
343	error = 1;
344	sprintf(lbuf, "%s/etc/fstab", rootdev);
345	if ((fd = open(lbuf, O_RDONLY)) < 0)
346		goto notfound;
347
348	/* loop reading lines from /etc/fstab    What was that about sscanf again? */
349	fstyp = NULL;
350	dev = NULL;
351	while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
352		if ((lbuf[0] == 0) || (lbuf[0] == '#'))
353			continue;
354
355		/* skip device name */
356		for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
357			;
358		if (*cp == 0)		/* misformatted */
359			continue;
360		/* delimit and save */
361		*cp++ = 0;
362		free(dev);
363		dev = strdup(lbuf);
364
365		/* skip whitespace up to mountpoint */
366		while ((*cp != 0) && isspace(*cp))
367			cp++;
368		/* must have /<space> to be root */
369		if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
370			continue;
371		/* skip whitespace up to fstype */
372		cp += 2;
373		while ((*cp != 0) && isspace(*cp))
374			cp++;
375		if (*cp == 0)		/* misformatted */
376			continue;
377		/* skip text to end of fstype and delimit */
378		ep = cp;
379		while ((*cp != 0) && !isspace(*cp))
380			cp++;
381		*cp = 0;
382		free(fstyp);
383		fstyp = strdup(ep);
384
385		/* skip whitespace up to mount options */
386		cp += 1;
387		while ((*cp != 0) && isspace(*cp))
388			cp++;
389		if (*cp == 0)           /* misformatted */
390			continue;
391		/* skip text to end of mount options and delimit */
392		ep = cp;
393		while ((*cp != 0) && !isspace(*cp))
394			cp++;
395		*cp = 0;
396		options = strdup(ep);
397		/* Build the <fstype>:<device> and save it in vfs.root.mountfrom */
398		sprintf(lbuf, "%s:%s", fstyp, dev);
399		setenv("vfs.root.mountfrom", lbuf, 0);
400
401		/* Don't override vfs.root.mountfrom.options if it is already set */
402		if (getenv("vfs.root.mountfrom.options") == NULL) {
403			/* save mount options */
404			setenv("vfs.root.mountfrom.options", options, 0);
405		}
406		free(options);
407		error = 0;
408		break;
409	}
410	close(fd);
411	free(dev);
412	free(fstyp);
413
414notfound:
415	if (error) {
416		const char *currdev;
417
418		currdev = getenv("currdev");
419		if (currdev != NULL && strncmp("zfs:", currdev, 4) == 0) {
420			cp = strdup(currdev);
421			cp[strlen(cp) - 1] = '\0';
422			setenv("vfs.root.mountfrom", cp, 0);
423			error = 0;
424			free(cp);
425		}
426	}
427
428	return(error);
429}
430
431static int
432loadakernel(int try, int argc, char* argv[])
433{
434	char *cp;
435
436	for (try = 0; (cp = getbootfile(try)) != NULL; try++)
437		if (mod_loadkld(cp, argc - 1, argv + 1) != 0)
438			printf("can't load '%s'\n", cp);
439		else
440			return 1;
441	return 0;
442}
443