xref: /openbmc/u-boot/tools/env/fw_env.c (revision 7d9b5bae)
1 /*
2  * (C) Copyright 2000-2008
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * (C) Copyright 2008
6  * Guennadi Liakhovetski, DENX Software Engineering, lg@denx.de.
7  *
8  * See file CREDITS for list of people who contributed to this
9  * project.
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of
14  * the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
24  * MA 02111-1307 USA
25  */
26 
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <stddef.h>
32 #include <string.h>
33 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <sys/stat.h>
36 #include <unistd.h>
37 
38 #ifdef MTD_OLD
39 # include <stdint.h>
40 # include <linux/mtd/mtd.h>
41 #else
42 # define  __user	/* nothing */
43 # include <mtd/mtd-user.h>
44 #endif
45 
46 #include "fw_env.h"
47 
48 #define	CMD_GETENV	"fw_printenv"
49 #define	CMD_SETENV	"fw_setenv"
50 
51 #define min(x, y) ({				\
52 	typeof(x) _min1 = (x);			\
53 	typeof(y) _min2 = (y);			\
54 	(void) (&_min1 == &_min2);		\
55 	_min1 < _min2 ? _min1 : _min2; })
56 
57 struct envdev_s {
58 	char devname[16];		/* Device name */
59 	ulong devoff;			/* Device offset */
60 	ulong env_size;			/* environment size */
61 	ulong erase_size;		/* device erase size */
62 	ulong env_sectors;		/* number of environment sectors */
63 	uint8_t mtd_type;		/* type of the MTD device */
64 };
65 
66 static struct envdev_s envdevices[2] =
67 {
68 	{
69 		.mtd_type = MTD_ABSENT,
70 	}, {
71 		.mtd_type = MTD_ABSENT,
72 	},
73 };
74 static int dev_current;
75 
76 #define DEVNAME(i)    envdevices[(i)].devname
77 #define DEVOFFSET(i)  envdevices[(i)].devoff
78 #define ENVSIZE(i)    envdevices[(i)].env_size
79 #define DEVESIZE(i)   envdevices[(i)].erase_size
80 #define ENVSECTORS(i) envdevices[(i)].env_sectors
81 #define DEVTYPE(i)    envdevices[(i)].mtd_type
82 
83 #define CFG_ENV_SIZE ENVSIZE(dev_current)
84 
85 #define ENV_SIZE      getenvsize()
86 
87 struct env_image_single {
88 	uint32_t	crc;	/* CRC32 over data bytes    */
89 	char		data[];
90 };
91 
92 struct env_image_redundant {
93 	uint32_t	crc;	/* CRC32 over data bytes    */
94 	unsigned char	flags;	/* active or obsolete */
95 	char		data[];
96 };
97 
98 enum flag_scheme {
99 	FLAG_NONE,
100 	FLAG_BOOLEAN,
101 	FLAG_INCREMENTAL,
102 };
103 
104 struct environment {
105 	void			*image;
106 	uint32_t		*crc;
107 	unsigned char		*flags;
108 	char			*data;
109 	enum flag_scheme	flag_scheme;
110 };
111 
112 static struct environment environment = {
113 	.flag_scheme = FLAG_NONE,
114 };
115 
116 static int HaveRedundEnv = 0;
117 
118 static unsigned char active_flag = 1;
119 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
120 static unsigned char obsolete_flag = 0;
121 
122 
123 #define XMK_STR(x)	#x
124 #define MK_STR(x)	XMK_STR(x)
125 
126 static char default_environment[] = {
127 #if defined(CONFIG_BOOTARGS)
128 	"bootargs=" CONFIG_BOOTARGS "\0"
129 #endif
130 #if defined(CONFIG_BOOTCOMMAND)
131 	"bootcmd=" CONFIG_BOOTCOMMAND "\0"
132 #endif
133 #if defined(CONFIG_RAMBOOTCOMMAND)
134 	"ramboot=" CONFIG_RAMBOOTCOMMAND "\0"
135 #endif
136 #if defined(CONFIG_NFSBOOTCOMMAND)
137 	"nfsboot=" CONFIG_NFSBOOTCOMMAND "\0"
138 #endif
139 #if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
140 	"bootdelay=" MK_STR (CONFIG_BOOTDELAY) "\0"
141 #endif
142 #if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0)
143 	"baudrate=" MK_STR (CONFIG_BAUDRATE) "\0"
144 #endif
145 #ifdef	CONFIG_LOADS_ECHO
146 	"loads_echo=" MK_STR (CONFIG_LOADS_ECHO) "\0"
147 #endif
148 #ifdef	CONFIG_ETHADDR
149 	"ethaddr=" MK_STR (CONFIG_ETHADDR) "\0"
150 #endif
151 #ifdef	CONFIG_ETH1ADDR
152 	"eth1addr=" MK_STR (CONFIG_ETH1ADDR) "\0"
153 #endif
154 #ifdef	CONFIG_ETH2ADDR
155 	"eth2addr=" MK_STR (CONFIG_ETH2ADDR) "\0"
156 #endif
157 #ifdef	CONFIG_ETH3ADDR
158 	"eth3addr=" MK_STR (CONFIG_ETH3ADDR) "\0"
159 #endif
160 #ifdef	CONFIG_ETHPRIME
161 	"ethprime=" CONFIG_ETHPRIME "\0"
162 #endif
163 #ifdef	CONFIG_IPADDR
164 	"ipaddr=" MK_STR (CONFIG_IPADDR) "\0"
165 #endif
166 #ifdef	CONFIG_SERVERIP
167 	"serverip=" MK_STR (CONFIG_SERVERIP) "\0"
168 #endif
169 #ifdef	CFG_AUTOLOAD
170 	"autoload=" CFG_AUTOLOAD "\0"
171 #endif
172 #ifdef	CONFIG_ROOTPATH
173 	"rootpath=" MK_STR (CONFIG_ROOTPATH) "\0"
174 #endif
175 #ifdef	CONFIG_GATEWAYIP
176 	"gatewayip=" MK_STR (CONFIG_GATEWAYIP) "\0"
177 #endif
178 #ifdef	CONFIG_NETMASK
179 	"netmask=" MK_STR (CONFIG_NETMASK) "\0"
180 #endif
181 #ifdef	CONFIG_HOSTNAME
182 	"hostname=" MK_STR (CONFIG_HOSTNAME) "\0"
183 #endif
184 #ifdef	CONFIG_BOOTFILE
185 	"bootfile=" MK_STR (CONFIG_BOOTFILE) "\0"
186 #endif
187 #ifdef	CONFIG_LOADADDR
188 	"loadaddr=" MK_STR (CONFIG_LOADADDR) "\0"
189 #endif
190 #ifdef	CONFIG_PREBOOT
191 	"preboot=" CONFIG_PREBOOT "\0"
192 #endif
193 #ifdef	CONFIG_CLOCKS_IN_MHZ
194 	"clocks_in_mhz=" "1" "\0"
195 #endif
196 #if defined(CONFIG_PCI_BOOTDELAY) && (CONFIG_PCI_BOOTDELAY > 0)
197 	"pcidelay=" MK_STR (CONFIG_PCI_BOOTDELAY) "\0"
198 #endif
199 #ifdef  CONFIG_EXTRA_ENV_SETTINGS
200 	CONFIG_EXTRA_ENV_SETTINGS
201 #endif
202 	"\0"		/* Termimate struct environment data with 2 NULs */
203 };
204 
205 static int flash_io (int mode);
206 static char *envmatch (char * s1, char * s2);
207 static int env_init (void);
208 static int parse_config (void);
209 
210 #if defined(CONFIG_FILE)
211 static int get_config (char *);
212 #endif
213 static inline ulong getenvsize (void)
214 {
215 	ulong rc = CFG_ENV_SIZE - sizeof (long);
216 
217 	if (HaveRedundEnv)
218 		rc -= sizeof (char);
219 	return rc;
220 }
221 
222 /*
223  * Search the environment for a variable.
224  * Return the value, if found, or NULL, if not found.
225  */
226 char *fw_getenv (char *name)
227 {
228 	char *env, *nxt;
229 
230 	if (env_init ())
231 		return NULL;
232 
233 	for (env = environment.data; *env; env = nxt + 1) {
234 		char *val;
235 
236 		for (nxt = env; *nxt; ++nxt) {
237 			if (nxt >= &environment.data[ENV_SIZE]) {
238 				fprintf (stderr, "## Error: "
239 					"environment not terminated\n");
240 				return NULL;
241 			}
242 		}
243 		val = envmatch (name, env);
244 		if (!val)
245 			continue;
246 		return val;
247 	}
248 	return NULL;
249 }
250 
251 /*
252  * Print the current definition of one, or more, or all
253  * environment variables
254  */
255 int fw_printenv (int argc, char *argv[])
256 {
257 	char *env, *nxt;
258 	int i, n_flag;
259 	int rc = 0;
260 
261 	if (env_init ())
262 		return -1;
263 
264 	if (argc == 1) {		/* Print all env variables  */
265 		for (env = environment.data; *env; env = nxt + 1) {
266 			for (nxt = env; *nxt; ++nxt) {
267 				if (nxt >= &environment.data[ENV_SIZE]) {
268 					fprintf (stderr, "## Error: "
269 						"environment not terminated\n");
270 					return -1;
271 				}
272 			}
273 
274 			printf ("%s\n", env);
275 		}
276 		return 0;
277 	}
278 
279 	if (strcmp (argv[1], "-n") == 0) {
280 		n_flag = 1;
281 		++argv;
282 		--argc;
283 		if (argc != 2) {
284 			fprintf (stderr, "## Error: "
285 				"`-n' option requires exactly one argument\n");
286 			return -1;
287 		}
288 	} else {
289 		n_flag = 0;
290 	}
291 
292 	for (i = 1; i < argc; ++i) {	/* print single env variables   */
293 		char *name = argv[i];
294 		char *val = NULL;
295 
296 		for (env = environment.data; *env; env = nxt + 1) {
297 
298 			for (nxt = env; *nxt; ++nxt) {
299 				if (nxt >= &environment.data[ENV_SIZE]) {
300 					fprintf (stderr, "## Error: "
301 						"environment not terminated\n");
302 					return -1;
303 				}
304 			}
305 			val = envmatch (name, env);
306 			if (val) {
307 				if (!n_flag) {
308 					fputs (name, stdout);
309 					putc ('=', stdout);
310 				}
311 				puts (val);
312 				break;
313 			}
314 		}
315 		if (!val) {
316 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
317 			rc = -1;
318 		}
319 	}
320 
321 	return rc;
322 }
323 
324 /*
325  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
326  * 0	  - OK
327  * EINVAL - need at least 1 argument
328  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
329  *	    modified or deleted
330  *
331  */
332 int fw_setenv (int argc, char *argv[])
333 {
334 	int i, len;
335 	char *env, *nxt;
336 	char *oldval = NULL;
337 	char *name;
338 
339 	if (argc < 2) {
340 		errno = EINVAL;
341 		return -1;
342 	}
343 
344 	if (env_init ())
345 		return -1;
346 
347 	name = argv[1];
348 
349 	/*
350 	 * search if variable with this name already exists
351 	 */
352 	for (nxt = env = environment.data; *env; env = nxt + 1) {
353 		for (nxt = env; *nxt; ++nxt) {
354 			if (nxt >= &environment.data[ENV_SIZE]) {
355 				fprintf (stderr, "## Error: "
356 					"environment not terminated\n");
357 				errno = EINVAL;
358 				return -1;
359 			}
360 		}
361 		if ((oldval = envmatch (name, env)) != NULL)
362 			break;
363 	}
364 
365 	/*
366 	 * Delete any existing definition
367 	 */
368 	if (oldval) {
369 		/*
370 		 * Ethernet Address and serial# can be set only once
371 		 */
372 		if ((strcmp (name, "ethaddr") == 0) ||
373 			(strcmp (name, "serial#") == 0)) {
374 			fprintf (stderr, "Can't overwrite \"%s\"\n", name);
375 			errno = EROFS;
376 			return -1;
377 		}
378 
379 		if (*++nxt == '\0') {
380 			*env = '\0';
381 		} else {
382 			for (;;) {
383 				*env = *nxt++;
384 				if ((*env == '\0') && (*nxt == '\0'))
385 					break;
386 				++env;
387 			}
388 		}
389 		*++env = '\0';
390 	}
391 
392 	/* Delete only ? */
393 	if (argc < 3)
394 		goto WRITE_FLASH;
395 
396 	/*
397 	 * Append new definition at the end
398 	 */
399 	for (env = environment.data; *env || *(env + 1); ++env);
400 	if (env > environment.data)
401 		++env;
402 	/*
403 	 * Overflow when:
404 	 * "name" + "=" + "val" +"\0\0"  > CFG_ENV_SIZE - (env-environment)
405 	 */
406 	len = strlen (name) + 2;
407 	/* add '=' for first arg, ' ' for all others */
408 	for (i = 2; i < argc; ++i) {
409 		len += strlen (argv[i]) + 1;
410 	}
411 	if (len > (&environment.data[ENV_SIZE] - env)) {
412 		fprintf (stderr,
413 			"Error: environment overflow, \"%s\" deleted\n",
414 			name);
415 		return -1;
416 	}
417 	while ((*env = *name++) != '\0')
418 		env++;
419 	for (i = 2; i < argc; ++i) {
420 		char *val = argv[i];
421 
422 		*env = (i == 2) ? '=' : ' ';
423 		while ((*++env = *val++) != '\0');
424 	}
425 
426 	/* end is marked with double '\0' */
427 	*++env = '\0';
428 
429   WRITE_FLASH:
430 
431 	/*
432 	 * Update CRC
433 	 */
434 	*environment.crc = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
435 
436 	/* write environment back to flash */
437 	if (flash_io (O_RDWR)) {
438 		fprintf (stderr, "Error: can't write fw_env to flash\n");
439 		return -1;
440 	}
441 
442 	return 0;
443 }
444 
445 /*
446  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
447  * 0	- block is good
448  * > 0	- block is bad
449  * < 0	- failed to test
450  */
451 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
452 {
453 	if (mtd_type == MTD_NANDFLASH) {
454 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
455 
456 		if (badblock < 0) {
457 			perror ("Cannot read bad block mark");
458 			return badblock;
459 		}
460 
461 		if (badblock) {
462 #ifdef DEBUG
463 			fprintf (stderr, "Bad block at 0x%llx, "
464 				 "skipping\n", *blockstart);
465 #endif
466 			return badblock;
467 		}
468 	}
469 
470 	return 0;
471 }
472 
473 /*
474  * Read data from flash at an offset into a provided buffer. On NAND it skips
475  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
476  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
477  */
478 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
479 			   off_t offset, uint8_t mtd_type)
480 {
481 	size_t blocklen;	/* erase / write length - one block on NAND,
482 				   0 on NOR */
483 	size_t processed = 0;	/* progress counter */
484 	size_t readlen = count;	/* current read length */
485 	off_t top_of_range;	/* end of the last block we may use */
486 	off_t block_seek;	/* offset inside the current block to the start
487 				   of the data */
488 	loff_t blockstart;	/* running start of the current block -
489 				   MEMGETBADBLOCK needs 64 bits */
490 	int rc;
491 
492 	/*
493 	 * Start of the first block to be read, relies on the fact, that
494 	 * erase sector size is always a power of 2
495 	 */
496 	blockstart = offset & ~(DEVESIZE (dev) - 1);
497 
498 	/* Offset inside a block */
499 	block_seek = offset - blockstart;
500 
501 	if (mtd_type == MTD_NANDFLASH) {
502 		/*
503 		 * NAND: calculate which blocks we are reading. We have
504 		 * to read one block at a time to skip bad blocks.
505 		 */
506 		blocklen = DEVESIZE (dev);
507 
508 		/*
509 		 * To calculate the top of the range, we have to use the
510 		 * global DEVOFFSET (dev), which can be different from offset
511 		 */
512 		top_of_range = (DEVOFFSET (dev) & ~(blocklen - 1)) +
513 			ENVSECTORS (dev) * blocklen;
514 
515 		/* Limit to one block for the first read */
516 		if (readlen > blocklen - block_seek)
517 			readlen = blocklen - block_seek;
518 	} else {
519 		blocklen = 0;
520 		top_of_range = offset + count;
521 	}
522 
523 	/* This only runs once on NOR flash */
524 	while (processed < count) {
525 		rc = flash_bad_block (fd, mtd_type, &blockstart);
526 		if (rc < 0)		/* block test failed */
527 			return -1;
528 
529 		if (blockstart + block_seek + readlen > top_of_range) {
530 			/* End of range is reached */
531 			fprintf (stderr,
532 				 "Too few good blocks within range\n");
533 			return -1;
534 		}
535 
536 		if (rc) {		/* block is bad */
537 			blockstart += blocklen;
538 			continue;
539 		}
540 
541 		/*
542 		 * If a block is bad, we retry in the next block at the same
543 		 * offset - see common/env_nand.c::writeenv()
544 		 */
545 		lseek (fd, blockstart + block_seek, SEEK_SET);
546 
547 		rc = read (fd, buf + processed, readlen);
548 		if (rc != readlen) {
549 			fprintf (stderr, "Read error on %s: %s\n",
550 				 DEVNAME (dev), strerror (errno));
551 			return -1;
552 		}
553 #ifdef DEBUG
554 		fprintf (stderr, "Read 0x%x bytes at 0x%llx\n",
555 			 rc, blockstart + block_seek);
556 #endif
557 		processed += readlen;
558 		readlen = min (blocklen, count - processed);
559 		block_seek = 0;
560 		blockstart += blocklen;
561 	}
562 
563 	return processed;
564 }
565 
566 /*
567  * Write count bytes at offset, but stay within ENVSETCORS (dev) sectors of
568  * DEVOFFSET (dev). Similar to the read case above, on NOR we erase and write
569  * the whole data at once.
570  */
571 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
572 			    off_t offset, uint8_t mtd_type)
573 {
574 	void *data;
575 	struct erase_info_user erase;
576 	size_t blocklen;	/* length of NAND block / NOR erase sector */
577 	size_t erase_len;	/* whole area that can be erased - may include
578 				   bad blocks */
579 	size_t erasesize;	/* erase / write length - one block on NAND,
580 				   whole area on NOR */
581 	size_t processed = 0;	/* progress counter */
582 	size_t write_total;	/* total size to actually write - excludinig
583 				   bad blocks */
584 	off_t erase_offset;	/* offset to the first erase block (aligned)
585 				   below offset */
586 	off_t block_seek;	/* offset inside the erase block to the start
587 				   of the data */
588 	off_t top_of_range;	/* end of the last block we may use */
589 	loff_t blockstart;	/* running start of the current block -
590 				   MEMGETBADBLOCK needs 64 bits */
591 	int rc;
592 
593 	blocklen = DEVESIZE (dev);
594 
595 	/* Erase sector size is always a power of 2 */
596 	top_of_range = (DEVOFFSET (dev) & ~(blocklen - 1)) +
597 		ENVSECTORS (dev) * blocklen;
598 
599 	erase_offset = offset & ~(blocklen - 1);
600 
601 	/* Maximum area we may use */
602 	erase_len = top_of_range - erase_offset;
603 
604 	blockstart = erase_offset;
605 	/* Offset inside a block */
606 	block_seek = offset - erase_offset;
607 
608 	/*
609 	 * Data size we actually have to write: from the start of the block
610 	 * to the start of the data, then count bytes of data, and to the
611 	 * end of the block
612 	 */
613 	write_total = (block_seek + count + blocklen - 1) & ~(blocklen - 1);
614 
615 	/*
616 	 * Support data anywhere within erase sectors: read out the complete
617 	 * area to be erased, replace the environment image, write the whole
618 	 * block back again.
619 	 */
620 	if (write_total > count) {
621 		data = malloc (erase_len);
622 		if (!data) {
623 			fprintf (stderr,
624 				 "Cannot malloc %u bytes: %s\n",
625 				 erase_len, strerror (errno));
626 			return -1;
627 		}
628 
629 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
630 				     mtd_type);
631 		if (write_total != rc)
632 			return -1;
633 
634 		/* Overwrite the old environment */
635 		memcpy (data + block_seek, buf, count);
636 	} else {
637 		/*
638 		 * We get here, iff offset is block-aligned and count is a
639 		 * multiple of blocklen - see write_total calculation above
640 		 */
641 		data = buf;
642 	}
643 
644 	if (mtd_type == MTD_NANDFLASH) {
645 		/*
646 		 * NAND: calculate which blocks we are writing. We have
647 		 * to write one block at a time to skip bad blocks.
648 		 */
649 		erasesize = blocklen;
650 	} else {
651 		erasesize = erase_len;
652 	}
653 
654 	erase.length = erasesize;
655 
656 	/* This only runs once on NOR flash */
657 	while (processed < write_total) {
658 		rc = flash_bad_block (fd, mtd_type, &blockstart);
659 		if (rc < 0)		/* block test failed */
660 			return rc;
661 
662 		if (blockstart + erasesize > top_of_range) {
663 			fprintf (stderr, "End of range reached, aborting\n");
664 			return -1;
665 		}
666 
667 		if (rc) {		/* block is bad */
668 			blockstart += blocklen;
669 			continue;
670 		}
671 
672 		erase.start = blockstart;
673 		ioctl (fd, MEMUNLOCK, &erase);
674 
675 		if (ioctl (fd, MEMERASE, &erase) != 0) {
676 			fprintf (stderr, "MTD erase error on %s: %s\n",
677 				 DEVNAME (dev),
678 				 strerror (errno));
679 			return -1;
680 		}
681 
682 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
683 			fprintf (stderr,
684 				 "Seek error on %s: %s\n",
685 				 DEVNAME (dev), strerror (errno));
686 			return -1;
687 		}
688 
689 #ifdef DEBUG
690 		printf ("Write 0x%x bytes at 0x%llx\n", erasesize, blockstart);
691 #endif
692 		if (write (fd, data + processed, erasesize) != erasesize) {
693 			fprintf (stderr, "Write error on %s: %s\n",
694 				 DEVNAME (dev), strerror (errno));
695 			return -1;
696 		}
697 
698 		ioctl (fd, MEMLOCK, &erase);
699 
700 		processed  += blocklen;
701 		block_seek = 0;
702 		blockstart += blocklen;
703 	}
704 
705 	if (write_total > count)
706 		free (data);
707 
708 	return processed;
709 }
710 
711 /*
712  * Set obsolete flag at offset - NOR flash only
713  */
714 static int flash_flag_obsolete (int dev, int fd, off_t offset)
715 {
716 	int rc;
717 
718 	/* This relies on the fact, that obsolete_flag == 0 */
719 	rc = lseek (fd, offset, SEEK_SET);
720 	if (rc < 0) {
721 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
722 			 DEVNAME (dev));
723 		return rc;
724 	}
725 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
726 	if (rc < 0)
727 		perror ("Could not set obsolete flag");
728 
729 	return rc;
730 }
731 
732 static int flash_write (int fd_current, int fd_target, int dev_target)
733 {
734 	int rc;
735 
736 	switch (environment.flag_scheme) {
737 	case FLAG_NONE:
738 		break;
739 	case FLAG_INCREMENTAL:
740 		(*environment.flags)++;
741 		break;
742 	case FLAG_BOOLEAN:
743 		*environment.flags = active_flag;
744 		break;
745 	default:
746 		fprintf (stderr, "Unimplemented flash scheme %u \n",
747 			 environment.flag_scheme);
748 		return -1;
749 	}
750 
751 #ifdef DEBUG
752 	printf ("Writing new environment at 0x%lx on %s\n",
753 		DEVOFFSET (dev_target), DEVNAME (dev_target));
754 #endif
755 	rc = flash_write_buf (dev_target, fd_target, environment.image,
756 			      CFG_ENV_SIZE, DEVOFFSET (dev_target),
757 			      DEVTYPE(dev_target));
758 	if (rc < 0)
759 		return rc;
760 
761 	if (environment.flag_scheme == FLAG_BOOLEAN) {
762 		/* Have to set obsolete flag */
763 		off_t offset = DEVOFFSET (dev_current) +
764 			offsetof (struct env_image_redundant, flags);
765 #ifdef DEBUG
766 		printf ("Setting obsolete flag in environment at 0x%lx on %s\n",
767 			DEVOFFSET (dev_current), DEVNAME (dev_current));
768 #endif
769 		flash_flag_obsolete (dev_current, fd_current, offset);
770 	}
771 
772 	return 0;
773 }
774 
775 static int flash_read (int fd)
776 {
777 	struct mtd_info_user mtdinfo;
778 	int rc;
779 
780 	rc = ioctl (fd, MEMGETINFO, &mtdinfo);
781 	if (rc < 0) {
782 		perror ("Cannot get MTD information");
783 		return -1;
784 	}
785 
786 	if (mtdinfo.type != MTD_NORFLASH && mtdinfo.type != MTD_NANDFLASH) {
787 		fprintf (stderr, "Unsupported flash type %u\n", mtdinfo.type);
788 		return -1;
789 	}
790 
791 	DEVTYPE(dev_current) = mtdinfo.type;
792 
793 	rc = flash_read_buf (dev_current, fd, environment.image, CFG_ENV_SIZE,
794 			     DEVOFFSET (dev_current), mtdinfo.type);
795 
796 	return (rc != CFG_ENV_SIZE) ? -1 : 0;
797 }
798 
799 static int flash_io (int mode)
800 {
801 	int fd_current, fd_target, rc, dev_target;
802 
803 	/* dev_current: fd_current, erase_current */
804 	fd_current = open (DEVNAME (dev_current), mode);
805 	if (fd_current < 0) {
806 		fprintf (stderr,
807 			 "Can't open %s: %s\n",
808 			 DEVNAME (dev_current), strerror (errno));
809 		return -1;
810 	}
811 
812 	if (mode == O_RDWR) {
813 		if (HaveRedundEnv) {
814 			/* switch to next partition for writing */
815 			dev_target = !dev_current;
816 			/* dev_target: fd_target, erase_target */
817 			fd_target = open (DEVNAME (dev_target), mode);
818 			if (fd_target < 0) {
819 				fprintf (stderr,
820 					 "Can't open %s: %s\n",
821 					 DEVNAME (dev_target),
822 					 strerror (errno));
823 				rc = -1;
824 				goto exit;
825 			}
826 		} else {
827 			dev_target = dev_current;
828 			fd_target = fd_current;
829 		}
830 
831 		rc = flash_write (fd_current, fd_target, dev_target);
832 
833 		if (HaveRedundEnv) {
834 			if (close (fd_target)) {
835 				fprintf (stderr,
836 					"I/O error on %s: %s\n",
837 					DEVNAME (dev_target),
838 					strerror (errno));
839 				rc = -1;
840 			}
841 		}
842 	} else {
843 		rc = flash_read (fd_current);
844 	}
845 
846 exit:
847 	if (close (fd_current)) {
848 		fprintf (stderr,
849 			 "I/O error on %s: %s\n",
850 			 DEVNAME (dev_current), strerror (errno));
851 		return -1;
852 	}
853 
854 	return rc;
855 }
856 
857 /*
858  * s1 is either a simple 'name', or a 'name=value' pair.
859  * s2 is a 'name=value' pair.
860  * If the names match, return the value of s2, else NULL.
861  */
862 
863 static char *envmatch (char * s1, char * s2)
864 {
865 
866 	while (*s1 == *s2++)
867 		if (*s1++ == '=')
868 			return s2;
869 	if (*s1 == '\0' && *(s2 - 1) == '=')
870 		return s2;
871 	return NULL;
872 }
873 
874 /*
875  * Prevent confusion if running from erased flash memory
876  */
877 static int env_init (void)
878 {
879 	int crc0, crc0_ok;
880 	char flag0;
881 	void *addr0;
882 
883 	int crc1, crc1_ok;
884 	char flag1;
885 	void *addr1;
886 
887 	struct env_image_single *single;
888 	struct env_image_redundant *redundant;
889 
890 	if (parse_config ())		/* should fill envdevices */
891 		return -1;
892 
893 	addr0 = calloc (1, CFG_ENV_SIZE);
894 	if (addr0 == NULL) {
895 		fprintf (stderr,
896 			"Not enough memory for environment (%ld bytes)\n",
897 			CFG_ENV_SIZE);
898 		return -1;
899 	}
900 
901 	/* read environment from FLASH to local buffer */
902 	environment.image = addr0;
903 
904 	if (HaveRedundEnv) {
905 		redundant = addr0;
906 		environment.crc		= &redundant->crc;
907 		environment.flags	= &redundant->flags;
908 		environment.data	= redundant->data;
909 	} else {
910 		single = addr0;
911 		environment.crc		= &single->crc;
912 		environment.flags	= NULL;
913 		environment.data	= single->data;
914 	}
915 
916 	dev_current = 0;
917 	if (flash_io (O_RDONLY))
918 		return -1;
919 
920 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
921 	crc0_ok = (crc0 == *environment.crc);
922 	if (!HaveRedundEnv) {
923 		if (!crc0_ok) {
924 			fprintf (stderr,
925 				"Warning: Bad CRC, using default environment\n");
926 			memcpy(environment.data, default_environment, sizeof default_environment);
927 		}
928 	} else {
929 		flag0 = *environment.flags;
930 
931 		dev_current = 1;
932 		addr1 = calloc (1, CFG_ENV_SIZE);
933 		if (addr1 == NULL) {
934 			fprintf (stderr,
935 				"Not enough memory for environment (%ld bytes)\n",
936 				CFG_ENV_SIZE);
937 			return -1;
938 		}
939 		redundant = addr1;
940 
941 		/*
942 		 * have to set environment.image for flash_read(), careful -
943 		 * other pointers in environment still point inside addr0
944 		 */
945 		environment.image = addr1;
946 		if (flash_io (O_RDONLY))
947 			return -1;
948 
949 		/* Check flag scheme compatibility */
950 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
951 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
952 			environment.flag_scheme = FLAG_BOOLEAN;
953 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
954 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
955 			environment.flag_scheme = FLAG_INCREMENTAL;
956 		} else {
957 			fprintf (stderr, "Incompatible flash types!\n");
958 			return -1;
959 		}
960 
961 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
962 		crc1_ok = (crc1 == redundant->crc);
963 		flag1 = redundant->flags;
964 
965 		if (crc0_ok && !crc1_ok) {
966 			dev_current = 0;
967 		} else if (!crc0_ok && crc1_ok) {
968 			dev_current = 1;
969 		} else if (!crc0_ok && !crc1_ok) {
970 			fprintf (stderr,
971 				"Warning: Bad CRC, using default environment\n");
972 			memcpy (environment.data, default_environment,
973 				sizeof default_environment);
974 			dev_current = 0;
975 		} else {
976 			switch (environment.flag_scheme) {
977 			case FLAG_BOOLEAN:
978 				if (flag0 == active_flag &&
979 				    flag1 == obsolete_flag) {
980 					dev_current = 0;
981 				} else if (flag0 == obsolete_flag &&
982 					   flag1 == active_flag) {
983 					dev_current = 1;
984 				} else if (flag0 == flag1) {
985 					dev_current = 0;
986 				} else if (flag0 == 0xFF) {
987 					dev_current = 0;
988 				} else if (flag1 == 0xFF) {
989 					dev_current = 1;
990 				} else {
991 					dev_current = 0;
992 				}
993 				break;
994 			case FLAG_INCREMENTAL:
995 				if ((flag0 == 255 && flag1 == 0) ||
996 				    flag1 > flag0)
997 					dev_current = 1;
998 				else if ((flag1 == 255 && flag0 == 0) ||
999 					 flag0 > flag1)
1000 					dev_current = 0;
1001 				else /* flags are equal - almost impossible */
1002 					dev_current = 0;
1003 				break;
1004 			default:
1005 				fprintf (stderr, "Unknown flag scheme %u \n",
1006 					 environment.flag_scheme);
1007 				return -1;
1008 			}
1009 		}
1010 
1011 		/*
1012 		 * If we are reading, we don't need the flag and the CRC any
1013 		 * more, if we are writing, we will re-calculate CRC and update
1014 		 * flags before writing out
1015 		 */
1016 		if (dev_current) {
1017 			environment.image	= addr1;
1018 			environment.crc		= &redundant->crc;
1019 			environment.flags	= &redundant->flags;
1020 			environment.data	= redundant->data;
1021 			free (addr0);
1022 		} else {
1023 			environment.image	= addr0;
1024 			/* Other pointers are already set */
1025 			free (addr1);
1026 		}
1027 	}
1028 	return 0;
1029 }
1030 
1031 
1032 static int parse_config ()
1033 {
1034 	struct stat st;
1035 
1036 #if defined(CONFIG_FILE)
1037 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1038 	if (get_config (CONFIG_FILE)) {
1039 		fprintf (stderr,
1040 			"Cannot parse config file: %s\n", strerror (errno));
1041 		return -1;
1042 	}
1043 #else
1044 	strcpy (DEVNAME (0), DEVICE1_NAME);
1045 	DEVOFFSET (0) = DEVICE1_OFFSET;
1046 	ENVSIZE (0) = ENV1_SIZE;
1047 	DEVESIZE (0) = DEVICE1_ESIZE;
1048 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1049 #ifdef HAVE_REDUND
1050 	strcpy (DEVNAME (1), DEVICE2_NAME);
1051 	DEVOFFSET (1) = DEVICE2_OFFSET;
1052 	ENVSIZE (1) = ENV2_SIZE;
1053 	DEVESIZE (1) = DEVICE2_ESIZE;
1054 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1055 	HaveRedundEnv = 1;
1056 #endif
1057 #endif
1058 	if (stat (DEVNAME (0), &st)) {
1059 		fprintf (stderr,
1060 			"Cannot access MTD device %s: %s\n",
1061 			DEVNAME (0), strerror (errno));
1062 		return -1;
1063 	}
1064 
1065 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1066 		fprintf (stderr,
1067 			"Cannot access MTD device %s: %s\n",
1068 			DEVNAME (1), strerror (errno));
1069 		return -1;
1070 	}
1071 	return 0;
1072 }
1073 
1074 #if defined(CONFIG_FILE)
1075 static int get_config (char *fname)
1076 {
1077 	FILE *fp;
1078 	int i = 0;
1079 	int rc;
1080 	char dump[128];
1081 
1082 	fp = fopen (fname, "r");
1083 	if (fp == NULL)
1084 		return -1;
1085 
1086 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1087 		/* Skip incomplete conversions and comment strings */
1088 		if (dump[0] == '#')
1089 			continue;
1090 
1091 		rc = sscanf (dump, "%s %lx %lx %lx %lx",
1092 			     DEVNAME (i),
1093 			     &DEVOFFSET (i),
1094 			     &ENVSIZE (i),
1095 			     &DEVESIZE (i),
1096 			     &ENVSECTORS (i));
1097 
1098 		if (rc < 4)
1099 			continue;
1100 
1101 		if (rc < 5)
1102 			/* Default - 1 sector */
1103 			ENVSECTORS (i) = 1;
1104 
1105 		i++;
1106 	}
1107 	fclose (fp);
1108 
1109 	HaveRedundEnv = i - 1;
1110 	if (!i) {			/* No valid entries found */
1111 		errno = EINVAL;
1112 		return -1;
1113 	} else
1114 		return 0;
1115 }
1116 #endif
1117