boot.c revision 329183 
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 329183 2018-02-12 20:51:28Z kevans $");
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			snprintf(command_errbuf, sizeof(command_errbuf),
65			    "can't boot '%s', kernel module already loaded", argv[1]);
66			return(CMD_ERROR);
67		}
68
69		/* find/load the kernel module */
70		if (mod_loadkld(argv[1], argc - 2, argv + 2) != 0)
71			return(CMD_ERROR);
72		/* we have consumed all arguments */
73		argc = 1;
74	}
75
76	/*
77	 * See if there is a kernel module already loaded
78	 */
79	if (file_findfile(NULL, NULL) == NULL)
80		if (loadakernel(0, argc - 1, argv + 1))
81			/* we have consumed all arguments */
82			argc = 1;
83
84	/*
85	 * Loaded anything yet?
86	 */
87	if ((fp = file_findfile(NULL, NULL)) == NULL) {
88		command_errmsg = "no bootable kernel";
89		return(CMD_ERROR);
90	}
91
92	/*
93	 * If we were given arguments, discard any previous.
94	 * XXX should we merge arguments?  Hard to DWIM.
95	 */
96	if (argc > 1) {
97		if (fp->f_args != NULL)
98			free(fp->f_args);
99		fp->f_args = unargv(argc - 1, argv + 1);
100	}
101
102	/* Hook for platform-specific autoloading of modules */
103	if (archsw.arch_autoload() != 0)
104		return(CMD_ERROR);
105
106	/* Call the exec handler from the loader matching the kernel */
107	file_formats[fp->f_loader]->l_exec(fp);
108	return(CMD_ERROR);
109}
110
111
112/*
113 * Autoboot after a delay
114 */
115
116COMMAND_SET(autoboot, "autoboot", "boot automatically after a delay", command_autoboot);
117
118static int
119command_autoboot(int argc, char *argv[])
120{
121	int		howlong;
122	char	*cp, *prompt;
123
124	prompt = NULL;
125	howlong = -1;
126	switch(argc) {
127	case 3:
128		prompt = argv[2];
129		/* FALLTHROUGH */
130	case 2:
131		howlong = strtol(argv[1], &cp, 0);
132		if (*cp != 0) {
133			snprintf(command_errbuf, sizeof(command_errbuf),
134			    "bad delay '%s'", argv[1]);
135			return(CMD_ERROR);
136		}
137		/* FALLTHROUGH */
138	case 1:
139		return(autoboot(howlong, prompt));
140	}
141
142	command_errmsg = "too many arguments";
143	return(CMD_ERROR);
144}
145
146/*
147 * Called before we go interactive.  If we think we can autoboot, and
148 * we haven't tried already, try now.
149 */
150void
151autoboot_maybe()
152{
153	char	*cp;
154
155	cp = getenv("autoboot_delay");
156	if ((autoboot_tried == 0) && ((cp == NULL) || strcasecmp(cp, "NO")))
157		autoboot(-1, NULL);		/* try to boot automatically */
158}
159
160int
161autoboot(int timeout, char *prompt)
162{
163	time_t	when, otime, ntime;
164	int		c, yes;
165	char	*argv[2], *cp, *ep;
166	char	*kernelname;
167#ifdef BOOT_PROMPT_123
168	const char	*seq = "123", *p = seq;
169#endif
170
171	autoboot_tried = 1;
172
173	if (timeout == -1) {
174		timeout = 10;
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 = 10;		/* Unparseable? Set default! */
180		}
181	}
182
183	kernelname = getenv("kernelname");
184	if (kernelname == NULL) {
185		argv[0] = NULL;
186		loadakernel(0, 0, argv);
187		kernelname = getenv("kernelname");
188		if (kernelname == NULL) {
189			command_errmsg = "no valid kernel found";
190			return(CMD_ERROR);
191		}
192	}
193
194	if (timeout >= 0) {
195		otime = time(NULL);
196		when = otime + timeout;	/* when to boot */
197
198		yes = 0;
199
200#ifdef BOOT_PROMPT_123
201		printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or "
202		    "1 2 3 sequence for command prompt." : prompt);
203#else
204		printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
205#endif
206
207		for (;;) {
208			if (ischar()) {
209				c = getchar();
210#ifdef BOOT_PROMPT_123
211				if ((c == '\r') || (c == '\n')) {
212					yes = 1;
213					break;
214				} else if (c != *p++)
215					p = seq;
216				if (*p == 0)
217					break;
218#else
219				if ((c == '\r') || (c == '\n'))
220					yes = 1;
221				break;
222#endif
223			}
224			ntime = time(NULL);
225			if (ntime >= when) {
226				yes = 1;
227				break;
228			}
229
230			if (ntime != otime) {
231				printf("\rBooting [%s] in %d second%s... ",
232				    kernelname, (int)(when - ntime),
233				    (when-ntime)==1?"":"s");
234				otime = ntime;
235			}
236		}
237	} else {
238		yes = 1;
239	}
240
241	if (yes)
242		printf("\rBooting [%s]...               ", kernelname);
243	putchar('\n');
244	if (yes) {
245		argv[0] = "boot";
246		argv[1] = NULL;
247		return(command_boot(1, argv));
248	}
249	return(CMD_OK);
250}
251
252/*
253 * Scrounge for the name of the (try)'th file we will try to boot.
254 */
255static char *
256getbootfile(int try)
257{
258	static char *name = NULL;
259	const char	*spec, *ep;
260	size_t	len;
261
262	/* we use dynamic storage */
263	if (name != NULL) {
264		free(name);
265		name = NULL;
266	}
267
268	/*
269	 * Try $bootfile, then try our builtin default
270	 */
271	if ((spec = getenv("bootfile")) == NULL)
272		spec = default_bootfiles;
273
274	while ((try > 0) && (spec != NULL)) {
275		spec = strchr(spec, ';');
276		if (spec)
277			spec++;	/* skip over the leading ';' */
278		try--;
279	}
280	if (spec != NULL) {
281		if ((ep = strchr(spec, ';')) != NULL) {
282			len = ep - spec;
283		} else {
284			len = strlen(spec);
285		}
286		name = malloc(len + 1);
287		strncpy(name, spec, len);
288		name[len] = 0;
289	}
290	if (name && name[0] == 0) {
291		free(name);
292		name = NULL;
293	}
294	return(name);
295}
296
297/*
298 * Try to find the /etc/fstab file on the filesystem (rootdev),
299 * which should be be the root filesystem, and parse it to find
300 * out what the kernel ought to think the root filesystem is.
301 *
302 * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
303 * so that the kernel can tell both which VFS and which node to use
304 * to mount the device.  If this variable's already set, don't
305 * overwrite it.
306 */
307int
308getrootmount(char *rootdev)
309{
310	char	lbuf[128], *cp, *ep, *dev, *fstyp, *options;
311	int		fd, error;
312
313	if (getenv("vfs.root.mountfrom") != NULL)
314		return(0);
315
316	error = 1;
317	sprintf(lbuf, "%s/etc/fstab", rootdev);
318	if ((fd = open(lbuf, O_RDONLY)) < 0)
319		goto notfound;
320
321	/* loop reading lines from /etc/fstab    What was that about sscanf again? */
322	fstyp = NULL;
323	dev = NULL;
324	while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
325		if ((lbuf[0] == 0) || (lbuf[0] == '#'))
326			continue;
327
328		/* skip device name */
329		for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
330			;
331		if (*cp == 0)		/* misformatted */
332			continue;
333		/* delimit and save */
334		*cp++ = 0;
335		free(dev);
336		dev = strdup(lbuf);
337
338		/* skip whitespace up to mountpoint */
339		while ((*cp != 0) && isspace(*cp))
340			cp++;
341		/* must have /<space> to be root */
342		if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
343			continue;
344		/* skip whitespace up to fstype */
345		cp += 2;
346		while ((*cp != 0) && isspace(*cp))
347			cp++;
348		if (*cp == 0)		/* misformatted */
349			continue;
350		/* skip text to end of fstype and delimit */
351		ep = cp;
352		while ((*cp != 0) && !isspace(*cp))
353			cp++;
354		*cp = 0;
355		free(fstyp);
356		fstyp = strdup(ep);
357
358		/* skip whitespace up to mount options */
359		cp += 1;
360		while ((*cp != 0) && isspace(*cp))
361			cp++;
362		if (*cp == 0)           /* misformatted */
363			continue;
364		/* skip text to end of mount options and delimit */
365		ep = cp;
366		while ((*cp != 0) && !isspace(*cp))
367			cp++;
368		*cp = 0;
369		options = strdup(ep);
370		/* Build the <fstype>:<device> and save it in vfs.root.mountfrom */
371		sprintf(lbuf, "%s:%s", fstyp, dev);
372		setenv("vfs.root.mountfrom", lbuf, 0);
373
374		/* Don't override vfs.root.mountfrom.options if it is already set */
375		if (getenv("vfs.root.mountfrom.options") == NULL) {
376			/* save mount options */
377			setenv("vfs.root.mountfrom.options", options, 0);
378		}
379		free(options);
380		error = 0;
381		break;
382	}
383	close(fd);
384	free(dev);
385	free(fstyp);
386
387notfound:
388	if (error) {
389		const char *currdev;
390
391		currdev = getenv("currdev");
392		if (currdev != NULL && strncmp("zfs:", currdev, 4) == 0) {
393			cp = strdup(currdev);
394			cp[strlen(cp) - 1] = '\0';
395			setenv("vfs.root.mountfrom", cp, 0);
396			error = 0;
397			free(cp);
398		}
399	}
400
401	return(error);
402}
403
404static int
405loadakernel(int try, int argc, char* argv[])
406{
407	char *cp;
408
409	for (try = 0; (cp = getbootfile(try)) != NULL; try++)
410		if (mod_loadkld(cp, argc - 1, argv + 1) != 0)
411			printf("can't load '%s'\n", cp);
412		else
413			return 1;
414	return 0;
415}
416