xref: /freebsd/stand/userboot/userboot/main.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*-
2  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3  * Copyright (c) 1998,2000 Doug Rabson <dfr@freebsd.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <stand.h>
32 #include <string.h>
33 #include <setjmp.h>
34 #include <sys/disk.h>
35 #include <sys/zfs_bootenv.h>
36 
37 #include "bootstrap.h"
38 #include "disk.h"
39 #include "libuserboot.h"
40 
41 #if defined(USERBOOT_ZFS_SUPPORT)
42 #include "libzfs.h"
43 
44 static void userboot_zfs_probe(void);
45 static int userboot_zfs_found;
46 #endif
47 
48 /* Minimum version required */
49 #define	USERBOOT_VERSION	USERBOOT_VERSION_3
50 
51 #define	LOADER_PATH		"/boot/loader"
52 #define	INTERP_MARKER		"$Interpreter:"
53 
54 #define	MALLOCSZ		(64*1024*1024)
55 
56 struct loader_callbacks *callbacks;
57 void *callbacks_arg;
58 
59 static jmp_buf jb;
60 
61 struct arch_switch archsw;	/* MI/MD interface boundary */
62 
63 static void	extract_currdev(void);
64 static void	check_interpreter(void);
65 
66 void
67 delay(int usec)
68 {
69 
70 	CALLBACK(delay, usec);
71 }
72 
73 void
74 exit(int v)
75 {
76 
77 	CALLBACK(exit, v);
78 	longjmp(jb, 1);
79 }
80 
81 static void
82 check_interpreter(void)
83 {
84 	struct stat st;
85 	size_t marklen, rdsize;
86 	const char *guest_interp, *my_interp;
87 	char *buf;
88 	int fd;
89 
90 	/*
91 	 * If we can't stat(2) or open(2) LOADER_PATH, then we'll fail by
92 	 * simply letting us roll on with whatever interpreter we were compiled
93 	 * with.  This is likely not going to be an issue in reality.
94 	 */
95 	buf =  NULL;
96 	if (stat(LOADER_PATH, &st) != 0)
97 		return;
98 	if ((fd = open(LOADER_PATH, O_RDONLY)) < 0)
99 		return;
100 
101 	rdsize = st.st_size;
102 	buf = malloc(rdsize);
103 	if (buf == NULL)
104 		goto out;
105 	if (read(fd, buf, rdsize) < rdsize)
106 		goto out;
107 
108 	marklen = strlen(INTERP_MARKER);
109 	my_interp = bootprog_interp + marklen;
110 
111 	/*
112 	 * Here we make the assumption that a loader binary without the
113 	 * interpreter marker is a 4th one.  All loader binaries going forward
114 	 * should have this properly specified, so our assumption should always
115 	 * be a good one.
116 	 */
117 	if ((guest_interp = memmem(buf, rdsize, INTERP_MARKER,
118 	    marklen)) != NULL)
119 		guest_interp += marklen;
120 	else
121 		guest_interp = "4th";
122 
123 	/*
124 	 * The guest interpreter may not have a version of loader that
125 	 * specifies the interpreter installed.  If that's the case, we'll
126 	 * assume it's legacy (4th) and request a swap to that if we're
127 	 * a Lua-userboot.
128 	 */
129 	if (strcmp(my_interp, guest_interp) != 0)
130 		CALLBACK(swap_interpreter, guest_interp);
131 out:
132 	free(buf);
133 	close(fd);
134 	return;
135 }
136 
137 void
138 loader_main(struct loader_callbacks *cb, void *arg, int version, int ndisks)
139 {
140 	static char mallocbuf[MALLOCSZ];
141 	char *var;
142 	int i;
143 
144 	if (version < USERBOOT_VERSION)
145 		abort();
146 
147 	callbacks = cb;
148 	callbacks_arg = arg;
149 	userboot_disk_maxunit = ndisks;
150 
151 	/*
152 	 * initialise the heap as early as possible.  Once this is done,
153 	 * alloc() is usable.
154 	 */
155 	setheap((void *)mallocbuf, (void *)(mallocbuf + sizeof(mallocbuf)));
156 
157 	/*
158 	 * Hook up the console
159 	 */
160 	cons_probe();
161 
162 	printf("\n%s", bootprog_info);
163 #if 0
164 	printf("Memory: %ld k\n", memsize() / 1024);
165 #endif
166 
167 	setenv("LINES", "24", 1);	/* optional */
168 
169 	/*
170 	 * Set custom environment variables
171 	 */
172 	i = 0;
173 	while (1) {
174 		var = CALLBACK(getenv, i++);
175 		if (var == NULL)
176 			break;
177 		putenv(var);
178 	}
179 
180 	archsw.arch_autoload = userboot_autoload;
181 	archsw.arch_getdev = userboot_getdev;
182 	archsw.arch_copyin = userboot_copyin;
183 	archsw.arch_copyout = userboot_copyout;
184 	archsw.arch_readin = userboot_readin;
185 #if defined(USERBOOT_ZFS_SUPPORT)
186 	archsw.arch_zfs_probe = userboot_zfs_probe;
187 #endif
188 
189 	/*
190 	 * Initialise the block cache. Set the upper limit.
191 	 */
192 	bcache_init(32768, 512);
193 	/*
194 	 * March through the device switch probing for things.
195 	 */
196 	for (i = 0; devsw[i] != NULL; i++)
197 		if (devsw[i]->dv_init != NULL)
198 			(devsw[i]->dv_init)();
199 
200 	extract_currdev();
201 
202 	/*
203 	 * Checking the interpreter isn't worth the overhead unless we
204 	 * actually have the swap_interpreter callback, so we actually version
205 	 * check here rather than later on.
206 	 */
207 	if (version >= USERBOOT_VERSION_5)
208 		check_interpreter();
209 
210 	if (setjmp(jb))
211 		return;
212 
213 	interact();			/* doesn't return */
214 
215 	exit(0);
216 }
217 
218 static void
219 set_currdev(const char *devname)
220 {
221 
222 	env_setenv("currdev", EV_VOLATILE, devname,
223 	    userboot_setcurrdev, env_nounset);
224 	env_setenv("loaddev", EV_VOLATILE, devname,
225 	    env_noset, env_nounset);
226 }
227 
228 /*
229  * Set the 'current device' by (if possible) recovering the boot device as
230  * supplied by the initial bootstrap.
231  */
232 static void
233 extract_currdev(void)
234 {
235 	struct disk_devdesc dev;
236 	struct devdesc *dd;
237 #if defined(USERBOOT_ZFS_SUPPORT)
238 	struct zfs_devdesc zdev;
239 	char *buf = NULL;
240 
241 	if (userboot_zfs_found) {
242 
243 		/* Leave the pool/root guid's unassigned */
244 		bzero(&zdev, sizeof(zdev));
245 		zdev.dd.d_dev = &zfs_dev;
246 
247 		init_zfs_boot_options(zfs_fmtdev(&zdev));
248 		dd = &zdev.dd;
249 	} else
250 #endif
251 
252 	if (userboot_disk_maxunit > 0) {
253 		dev.dd.d_dev = &userboot_disk;
254 		dev.dd.d_unit = 0;
255 		dev.d_slice = D_SLICEWILD;
256 		dev.d_partition = D_PARTWILD;
257 		/*
258 		 * If we cannot auto-detect the partition type then
259 		 * access the disk as a raw device.
260 		 */
261 		if (dev.dd.d_dev->dv_open(NULL, &dev)) {
262 			dev.d_slice = D_SLICENONE;
263 			dev.d_partition = D_PARTNONE;
264 		}
265 		dd = &dev.dd;
266 	} else {
267 		dev.dd.d_dev = &host_dev;
268 		dev.dd.d_unit = 0;
269 		dd = &dev.dd;
270 	}
271 
272 	set_currdev(userboot_fmtdev(dd));
273 
274 #if defined(USERBOOT_ZFS_SUPPORT)
275 	if (userboot_zfs_found) {
276 		buf = malloc(VDEV_PAD_SIZE);
277 		if (buf != NULL) {
278 			if (zfs_get_bootonce(&zdev, OS_BOOTONCE, buf,
279 			    VDEV_PAD_SIZE) == 0) {
280 				printf("zfs bootonce: %s\n", buf);
281 				set_currdev(buf);
282 				setenv("zfs-bootonce", buf, 1);
283 			}
284 			free(buf);
285 			(void) zfs_attach_nvstore(&zdev);
286 		}
287 	}
288 #endif
289 }
290 
291 #if defined(USERBOOT_ZFS_SUPPORT)
292 static void
293 userboot_zfs_probe(void)
294 {
295 	char devname[32];
296 	uint64_t pool_guid;
297 	int unit;
298 
299 	/*
300 	 * Open all the disks we can find and see if we can reconstruct
301 	 * ZFS pools from them. Record if any were found.
302 	 */
303 	for (unit = 0; unit < userboot_disk_maxunit; unit++) {
304 		sprintf(devname, "disk%d:", unit);
305 		pool_guid = 0;
306 		zfs_probe_dev(devname, &pool_guid);
307 		if (pool_guid != 0)
308 			userboot_zfs_found = 1;
309 	}
310 }
311 #endif
312 
313 COMMAND_SET(quit, "quit", "exit the loader", command_quit);
314 
315 static int
316 command_quit(int argc, char *argv[])
317 {
318 
319 	exit(USERBOOT_EXIT_QUIT);
320 	return (CMD_OK);
321 }
322 
323 COMMAND_SET(reboot, "reboot", "reboot the system", command_reboot);
324 
325 static int
326 command_reboot(int argc, char *argv[])
327 {
328 
329 	exit(USERBOOT_EXIT_REBOOT);
330 	return (CMD_OK);
331 }
332