xref: /openbmc/u-boot/tools/env/fw_env.c (revision fc0db132)
1 /*
2  * (C) Copyright 2000-2010
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 WHITESPACE(c) ((c == '\t') || (c == ' '))
49 
50 #define min(x, y) ({				\
51 	typeof(x) _min1 = (x);			\
52 	typeof(y) _min2 = (y);			\
53 	(void) (&_min1 == &_min2);		\
54 	_min1 < _min2 ? _min1 : _min2; })
55 
56 struct envdev_s {
57 	char devname[16];		/* Device name */
58 	ulong devoff;			/* Device offset */
59 	ulong env_size;			/* environment size */
60 	ulong erase_size;		/* device erase size */
61 	ulong env_sectors;		/* number of environment sectors */
62 	uint8_t mtd_type;		/* type of the MTD device */
63 };
64 
65 static struct envdev_s envdevices[2] =
66 {
67 	{
68 		.mtd_type = MTD_ABSENT,
69 	}, {
70 		.mtd_type = MTD_ABSENT,
71 	},
72 };
73 static int dev_current;
74 
75 #define DEVNAME(i)    envdevices[(i)].devname
76 #define DEVOFFSET(i)  envdevices[(i)].devoff
77 #define ENVSIZE(i)    envdevices[(i)].env_size
78 #define DEVESIZE(i)   envdevices[(i)].erase_size
79 #define ENVSECTORS(i) envdevices[(i)].env_sectors
80 #define DEVTYPE(i)    envdevices[(i)].mtd_type
81 
82 #define CONFIG_ENV_SIZE ENVSIZE(dev_current)
83 
84 #define ENV_SIZE      getenvsize()
85 
86 struct env_image_single {
87 	uint32_t	crc;	/* CRC32 over data bytes    */
88 	char		data[];
89 };
90 
91 struct env_image_redundant {
92 	uint32_t	crc;	/* CRC32 over data bytes    */
93 	unsigned char	flags;	/* active or obsolete */
94 	char		data[];
95 };
96 
97 enum flag_scheme {
98 	FLAG_NONE,
99 	FLAG_BOOLEAN,
100 	FLAG_INCREMENTAL,
101 };
102 
103 struct environment {
104 	void			*image;
105 	uint32_t		*crc;
106 	unsigned char		*flags;
107 	char			*data;
108 	enum flag_scheme	flag_scheme;
109 };
110 
111 static struct environment environment = {
112 	.flag_scheme = FLAG_NONE,
113 };
114 
115 static int HaveRedundEnv = 0;
116 
117 static unsigned char active_flag = 1;
118 /* obsolete_flag must be 0 to efficiently set it on NOR flash without erasing */
119 static unsigned char obsolete_flag = 0;
120 
121 
122 #define XMK_STR(x)	#x
123 #define MK_STR(x)	XMK_STR(x)
124 
125 static char default_environment[] = {
126 #if defined(CONFIG_BOOTARGS)
127 	"bootargs=" CONFIG_BOOTARGS "\0"
128 #endif
129 #if defined(CONFIG_BOOTCOMMAND)
130 	"bootcmd=" CONFIG_BOOTCOMMAND "\0"
131 #endif
132 #if defined(CONFIG_RAMBOOTCOMMAND)
133 	"ramboot=" CONFIG_RAMBOOTCOMMAND "\0"
134 #endif
135 #if defined(CONFIG_NFSBOOTCOMMAND)
136 	"nfsboot=" CONFIG_NFSBOOTCOMMAND "\0"
137 #endif
138 #if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
139 	"bootdelay=" MK_STR (CONFIG_BOOTDELAY) "\0"
140 #endif
141 #if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0)
142 	"baudrate=" MK_STR (CONFIG_BAUDRATE) "\0"
143 #endif
144 #ifdef	CONFIG_LOADS_ECHO
145 	"loads_echo=" MK_STR (CONFIG_LOADS_ECHO) "\0"
146 #endif
147 #ifdef	CONFIG_ETHADDR
148 	"ethaddr=" MK_STR (CONFIG_ETHADDR) "\0"
149 #endif
150 #ifdef	CONFIG_ETH1ADDR
151 	"eth1addr=" MK_STR (CONFIG_ETH1ADDR) "\0"
152 #endif
153 #ifdef	CONFIG_ETH2ADDR
154 	"eth2addr=" MK_STR (CONFIG_ETH2ADDR) "\0"
155 #endif
156 #ifdef	CONFIG_ETH3ADDR
157 	"eth3addr=" MK_STR (CONFIG_ETH3ADDR) "\0"
158 #endif
159 #ifdef	CONFIG_ETH4ADDR
160 	"eth4addr=" MK_STR (CONFIG_ETH4ADDR) "\0"
161 #endif
162 #ifdef	CONFIG_ETH5ADDR
163 	"eth5addr=" MK_STR (CONFIG_ETH5ADDR) "\0"
164 #endif
165 #ifdef	CONFIG_ETHPRIME
166 	"ethprime=" CONFIG_ETHPRIME "\0"
167 #endif
168 #ifdef	CONFIG_IPADDR
169 	"ipaddr=" MK_STR (CONFIG_IPADDR) "\0"
170 #endif
171 #ifdef	CONFIG_SERVERIP
172 	"serverip=" MK_STR (CONFIG_SERVERIP) "\0"
173 #endif
174 #ifdef	CONFIG_SYS_AUTOLOAD
175 	"autoload=" CONFIG_SYS_AUTOLOAD "\0"
176 #endif
177 #ifdef	CONFIG_ROOTPATH
178 	"rootpath=" MK_STR (CONFIG_ROOTPATH) "\0"
179 #endif
180 #ifdef	CONFIG_GATEWAYIP
181 	"gatewayip=" MK_STR (CONFIG_GATEWAYIP) "\0"
182 #endif
183 #ifdef	CONFIG_NETMASK
184 	"netmask=" MK_STR (CONFIG_NETMASK) "\0"
185 #endif
186 #ifdef	CONFIG_HOSTNAME
187 	"hostname=" MK_STR (CONFIG_HOSTNAME) "\0"
188 #endif
189 #ifdef	CONFIG_BOOTFILE
190 	"bootfile=" MK_STR (CONFIG_BOOTFILE) "\0"
191 #endif
192 #ifdef	CONFIG_LOADADDR
193 	"loadaddr=" MK_STR (CONFIG_LOADADDR) "\0"
194 #endif
195 #ifdef	CONFIG_PREBOOT
196 	"preboot=" CONFIG_PREBOOT "\0"
197 #endif
198 #ifdef	CONFIG_CLOCKS_IN_MHZ
199 	"clocks_in_mhz=" "1" "\0"
200 #endif
201 #if defined(CONFIG_PCI_BOOTDELAY) && (CONFIG_PCI_BOOTDELAY > 0)
202 	"pcidelay=" MK_STR (CONFIG_PCI_BOOTDELAY) "\0"
203 #endif
204 #ifdef  CONFIG_EXTRA_ENV_SETTINGS
205 	CONFIG_EXTRA_ENV_SETTINGS
206 #endif
207 	"\0"		/* Termimate struct environment data with 2 NULs */
208 };
209 
210 static int flash_io (int mode);
211 static char *envmatch (char * s1, char * s2);
212 static int parse_config (void);
213 
214 #if defined(CONFIG_FILE)
215 static int get_config (char *);
216 #endif
217 static inline ulong getenvsize (void)
218 {
219 	ulong rc = CONFIG_ENV_SIZE - sizeof (long);
220 
221 	if (HaveRedundEnv)
222 		rc -= sizeof (char);
223 	return rc;
224 }
225 
226 static char *fw_string_blank(char *s, int noblank)
227 {
228 	int i;
229 	int len = strlen(s);
230 
231 	for (i = 0; i < len; i++, s++) {
232 		if ((noblank && !WHITESPACE(*s)) ||
233 			(!noblank && WHITESPACE(*s)))
234 			break;
235 	}
236 	if (i == len)
237 		return NULL;
238 
239 	return s;
240 }
241 
242 /*
243  * Search the environment for a variable.
244  * Return the value, if found, or NULL, if not found.
245  */
246 char *fw_getenv (char *name)
247 {
248 	char *env, *nxt;
249 
250 	if (fw_env_open())
251 		return NULL;
252 
253 	for (env = environment.data; *env; env = nxt + 1) {
254 		char *val;
255 
256 		for (nxt = env; *nxt; ++nxt) {
257 			if (nxt >= &environment.data[ENV_SIZE]) {
258 				fprintf (stderr, "## Error: "
259 					"environment not terminated\n");
260 				return NULL;
261 			}
262 		}
263 		val = envmatch (name, env);
264 		if (!val)
265 			continue;
266 		return val;
267 	}
268 	return NULL;
269 }
270 
271 /*
272  * Print the current definition of one, or more, or all
273  * environment variables
274  */
275 int fw_printenv (int argc, char *argv[])
276 {
277 	char *env, *nxt;
278 	int i, n_flag;
279 	int rc = 0;
280 
281 	if (fw_env_open())
282 		return -1;
283 
284 	if (argc == 1) {		/* Print all env variables  */
285 		for (env = environment.data; *env; env = nxt + 1) {
286 			for (nxt = env; *nxt; ++nxt) {
287 				if (nxt >= &environment.data[ENV_SIZE]) {
288 					fprintf (stderr, "## Error: "
289 						"environment not terminated\n");
290 					return -1;
291 				}
292 			}
293 
294 			printf ("%s\n", env);
295 		}
296 		return 0;
297 	}
298 
299 	if (strcmp (argv[1], "-n") == 0) {
300 		n_flag = 1;
301 		++argv;
302 		--argc;
303 		if (argc != 2) {
304 			fprintf (stderr, "## Error: "
305 				"`-n' option requires exactly one argument\n");
306 			return -1;
307 		}
308 	} else {
309 		n_flag = 0;
310 	}
311 
312 	for (i = 1; i < argc; ++i) {	/* print single env variables   */
313 		char *name = argv[i];
314 		char *val = NULL;
315 
316 		for (env = environment.data; *env; env = nxt + 1) {
317 
318 			for (nxt = env; *nxt; ++nxt) {
319 				if (nxt >= &environment.data[ENV_SIZE]) {
320 					fprintf (stderr, "## Error: "
321 						"environment not terminated\n");
322 					return -1;
323 				}
324 			}
325 			val = envmatch (name, env);
326 			if (val) {
327 				if (!n_flag) {
328 					fputs (name, stdout);
329 					putc ('=', stdout);
330 				}
331 				puts (val);
332 				break;
333 			}
334 		}
335 		if (!val) {
336 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
337 			rc = -1;
338 		}
339 	}
340 
341 	return rc;
342 }
343 
344 int fw_env_close(void)
345 {
346 	/*
347 	 * Update CRC
348 	 */
349 	*environment.crc = crc32(0, (uint8_t *) environment.data, ENV_SIZE);
350 
351 	/* write environment back to flash */
352 	if (flash_io(O_RDWR)) {
353 		fprintf(stderr,
354 			"Error: can't write fw_env to flash\n");
355 			return -1;
356 	}
357 
358 	return 0;
359 }
360 
361 
362 /*
363  * Set/Clear a single variable in the environment.
364  * This is called in sequence to update the environment
365  * in RAM without updating the copy in flash after each set
366  */
367 int fw_env_write(char *name, char *value)
368 {
369 	int len;
370 	char *env, *nxt;
371 	char *oldval = NULL;
372 
373 	/*
374 	 * search if variable with this name already exists
375 	 */
376 	for (nxt = env = environment.data; *env; env = nxt + 1) {
377 		for (nxt = env; *nxt; ++nxt) {
378 			if (nxt >= &environment.data[ENV_SIZE]) {
379 				fprintf(stderr, "## Error: "
380 					"environment not terminated\n");
381 				errno = EINVAL;
382 				return -1;
383 			}
384 		}
385 		if ((oldval = envmatch (name, env)) != NULL)
386 			break;
387 	}
388 
389 	/*
390 	 * Delete any existing definition
391 	 */
392 	if (oldval) {
393 		/*
394 		 * Ethernet Address and serial# can be set only once
395 		 */
396 		if ((strcmp (name, "ethaddr") == 0) ||
397 			(strcmp (name, "serial#") == 0)) {
398 			fprintf (stderr, "Can't overwrite \"%s\"\n", name);
399 			errno = EROFS;
400 			return -1;
401 		}
402 
403 		if (*++nxt == '\0') {
404 			*env = '\0';
405 		} else {
406 			for (;;) {
407 				*env = *nxt++;
408 				if ((*env == '\0') && (*nxt == '\0'))
409 					break;
410 				++env;
411 			}
412 		}
413 		*++env = '\0';
414 	}
415 
416 	/* Delete only ? */
417 	if (!value || !strlen(value))
418 		return 0;
419 
420 	/*
421 	 * Append new definition at the end
422 	 */
423 	for (env = environment.data; *env || *(env + 1); ++env);
424 	if (env > environment.data)
425 		++env;
426 	/*
427 	 * Overflow when:
428 	 * "name" + "=" + "val" +"\0\0"  > CONFIG_ENV_SIZE - (env-environment)
429 	 */
430 	len = strlen (name) + 2;
431 	/* add '=' for first arg, ' ' for all others */
432 	len += strlen(value) + 1;
433 
434 	if (len > (&environment.data[ENV_SIZE] - env)) {
435 		fprintf (stderr,
436 			"Error: environment overflow, \"%s\" deleted\n",
437 			name);
438 		return -1;
439 	}
440 
441 	while ((*env = *name++) != '\0')
442 		env++;
443 	*env = '=';
444 	while ((*++env = *value++) != '\0')
445 		;
446 
447 	/* end is marked with double '\0' */
448 	*++env = '\0';
449 
450 	return 0;
451 }
452 
453 /*
454  * Deletes or sets environment variables. Returns -1 and sets errno error codes:
455  * 0	  - OK
456  * EINVAL - need at least 1 argument
457  * EROFS  - certain variables ("ethaddr", "serial#") cannot be
458  *	    modified or deleted
459  *
460  */
461 int fw_setenv(int argc, char *argv[])
462 {
463 	int i, len;
464 	char *name;
465 	char *value = NULL;
466 	char *tmpval = NULL;
467 
468 	if (argc < 2) {
469 		errno = EINVAL;
470 		return -1;
471 	}
472 
473 	if (fw_env_open()) {
474 		fprintf(stderr, "Error: environment not initialized\n");
475 		return -1;
476 	}
477 
478 	name = argv[1];
479 
480 	len = strlen(name) + 2;
481 	for (i = 2; i < argc; ++i)
482 		len += strlen(argv[i]) + 1;
483 
484 	/* Allocate enough place to the data string */
485 	for (i = 2; i < argc; ++i) {
486 		char *val = argv[i];
487 		if (!value) {
488 			value = (char *)malloc(len - strlen(name));
489 			if (!value) {
490 				fprintf(stderr,
491 				"Cannot malloc %u bytes: %s\n",
492 				len - strlen(name), strerror(errno));
493 				return -1;
494 			}
495 			memset(value, 0, len - strlen(name));
496 			tmpval = value;
497 		}
498 		if (i != 2)
499 			*tmpval++ = ' ';
500 		while (*val != '\0')
501 			*tmpval++ = *val++;
502 	}
503 
504 	fw_env_write(name, value);
505 
506 	if (value)
507 		free(value);
508 
509 	return fw_env_close();
510 }
511 
512 /*
513  * Parse  a file  and configure the u-boot variables.
514  * The script file has a very simple format, as follows:
515  *
516  * Each line has a couple with name, value:
517  * <white spaces>variable_name<white spaces>variable_value
518  *
519  * Both variable_name and variable_value are interpreted as strings.
520  * Any character after <white spaces> and before ending \r\n is interpreted
521  * as variable's value (no comment allowed on these lines !)
522  *
523  * Comments are allowed if the first character in the line is #
524  *
525  * Returns -1 and sets errno error codes:
526  * 0	  - OK
527  * -1     - Error
528  */
529 int fw_parse_script(char *fname)
530 {
531 	FILE *fp;
532 	char dump[1024];	/* Maximum line length in the file */
533 	char *name;
534 	char *val;
535 	int lineno = 0;
536 	int len;
537 	int ret = 0;
538 
539 	if (fw_env_open()) {
540 		fprintf(stderr, "Error: environment not initialized\n");
541 		return -1;
542 	}
543 
544 	if (strcmp(fname, "-") == 0)
545 		fp = stdin;
546 	else {
547 		fp = fopen(fname, "r");
548 		if (fp == NULL) {
549 			fprintf(stderr, "I cannot open %s for reading\n",
550 				 fname);
551 			return -1;
552 		}
553 	}
554 
555 	while (fgets(dump, sizeof(dump), fp)) {
556 		lineno++;
557 		len = strlen(dump);
558 
559 		/*
560 		 * Read a whole line from the file. If the line is too long
561 		 * or is not terminated, reports an error and exit.
562 		 */
563 		if (dump[len - 1] != '\n') {
564 			fprintf(stderr,
565 			"Line %d not corrected terminated or too long\n",
566 				lineno);
567 			ret = -1;
568 			break;
569 		}
570 
571 		/* Drop ending line feed / carriage return */
572 		while (len > 0 && (dump[len - 1] == '\n' ||
573 				dump[len - 1] == '\r')) {
574 			dump[len - 1] = '\0';
575 			len--;
576 		}
577 
578 		/* Skip comment or empty lines */
579 		if ((len == 0) || dump[0] == '#')
580 			continue;
581 
582 		/*
583 		 * Search for variable's name,
584 		 * remove leading whitespaces
585 		 */
586 		name = fw_string_blank(dump, 1);
587 		if (!name)
588 			continue;
589 
590 		/* The first white space is the end of variable name */
591 		val = fw_string_blank(name, 0);
592 		len = strlen(name);
593 		if (val) {
594 			*val++ = '\0';
595 			if ((val - name) < len)
596 				val = fw_string_blank(val, 1);
597 			else
598 				val = NULL;
599 		}
600 
601 #ifdef DEBUG
602 		fprintf(stderr, "Setting %s : %s\n",
603 			name, val ? val : " removed");
604 #endif
605 
606 		/*
607 		 * If there is an error setting a variable,
608 		 * try to save the environment and returns an error
609 		 */
610 		if (fw_env_write(name, val)) {
611 			fprintf(stderr,
612 			"fw_env_write returns with error : %s\n",
613 				strerror(errno));
614 			ret = -1;
615 			break;
616 		}
617 
618 	}
619 
620 	/* Close file if not stdin */
621 	if (strcmp(fname, "-") != 0)
622 		fclose(fp);
623 
624 	ret |= fw_env_close();
625 
626 	return ret;
627 
628 }
629 
630 /*
631  * Test for bad block on NAND, just returns 0 on NOR, on NAND:
632  * 0	- block is good
633  * > 0	- block is bad
634  * < 0	- failed to test
635  */
636 static int flash_bad_block (int fd, uint8_t mtd_type, loff_t *blockstart)
637 {
638 	if (mtd_type == MTD_NANDFLASH) {
639 		int badblock = ioctl (fd, MEMGETBADBLOCK, blockstart);
640 
641 		if (badblock < 0) {
642 			perror ("Cannot read bad block mark");
643 			return badblock;
644 		}
645 
646 		if (badblock) {
647 #ifdef DEBUG
648 			fprintf (stderr, "Bad block at 0x%llx, "
649 				 "skipping\n", *blockstart);
650 #endif
651 			return badblock;
652 		}
653 	}
654 
655 	return 0;
656 }
657 
658 /*
659  * Read data from flash at an offset into a provided buffer. On NAND it skips
660  * bad blocks but makes sure it stays within ENVSECTORS (dev) starting from
661  * the DEVOFFSET (dev) block. On NOR the loop is only run once.
662  */
663 static int flash_read_buf (int dev, int fd, void *buf, size_t count,
664 			   off_t offset, uint8_t mtd_type)
665 {
666 	size_t blocklen;	/* erase / write length - one block on NAND,
667 				   0 on NOR */
668 	size_t processed = 0;	/* progress counter */
669 	size_t readlen = count;	/* current read length */
670 	off_t top_of_range;	/* end of the last block we may use */
671 	off_t block_seek;	/* offset inside the current block to the start
672 				   of the data */
673 	loff_t blockstart;	/* running start of the current block -
674 				   MEMGETBADBLOCK needs 64 bits */
675 	int rc;
676 
677 	/*
678 	 * Start of the first block to be read, relies on the fact, that
679 	 * erase sector size is always a power of 2
680 	 */
681 	blockstart = offset & ~(DEVESIZE (dev) - 1);
682 
683 	/* Offset inside a block */
684 	block_seek = offset - blockstart;
685 
686 	if (mtd_type == MTD_NANDFLASH) {
687 		/*
688 		 * NAND: calculate which blocks we are reading. We have
689 		 * to read one block at a time to skip bad blocks.
690 		 */
691 		blocklen = DEVESIZE (dev);
692 
693 		/*
694 		 * To calculate the top of the range, we have to use the
695 		 * global DEVOFFSET (dev), which can be different from offset
696 		 */
697 		top_of_range = (DEVOFFSET (dev) & ~(blocklen - 1)) +
698 			ENVSECTORS (dev) * blocklen;
699 
700 		/* Limit to one block for the first read */
701 		if (readlen > blocklen - block_seek)
702 			readlen = blocklen - block_seek;
703 	} else {
704 		blocklen = 0;
705 		top_of_range = offset + count;
706 	}
707 
708 	/* This only runs once on NOR flash */
709 	while (processed < count) {
710 		rc = flash_bad_block (fd, mtd_type, &blockstart);
711 		if (rc < 0)		/* block test failed */
712 			return -1;
713 
714 		if (blockstart + block_seek + readlen > top_of_range) {
715 			/* End of range is reached */
716 			fprintf (stderr,
717 				 "Too few good blocks within range\n");
718 			return -1;
719 		}
720 
721 		if (rc) {		/* block is bad */
722 			blockstart += blocklen;
723 			continue;
724 		}
725 
726 		/*
727 		 * If a block is bad, we retry in the next block at the same
728 		 * offset - see common/env_nand.c::writeenv()
729 		 */
730 		lseek (fd, blockstart + block_seek, SEEK_SET);
731 
732 		rc = read (fd, buf + processed, readlen);
733 		if (rc != readlen) {
734 			fprintf (stderr, "Read error on %s: %s\n",
735 				 DEVNAME (dev), strerror (errno));
736 			return -1;
737 		}
738 #ifdef DEBUG
739 		fprintf (stderr, "Read 0x%x bytes at 0x%llx\n",
740 			 rc, blockstart + block_seek);
741 #endif
742 		processed += readlen;
743 		readlen = min (blocklen, count - processed);
744 		block_seek = 0;
745 		blockstart += blocklen;
746 	}
747 
748 	return processed;
749 }
750 
751 /*
752  * Write count bytes at offset, but stay within ENVSETCORS (dev) sectors of
753  * DEVOFFSET (dev). Similar to the read case above, on NOR we erase and write
754  * the whole data at once.
755  */
756 static int flash_write_buf (int dev, int fd, void *buf, size_t count,
757 			    off_t offset, uint8_t mtd_type)
758 {
759 	void *data;
760 	struct erase_info_user erase;
761 	size_t blocklen;	/* length of NAND block / NOR erase sector */
762 	size_t erase_len;	/* whole area that can be erased - may include
763 				   bad blocks */
764 	size_t erasesize;	/* erase / write length - one block on NAND,
765 				   whole area on NOR */
766 	size_t processed = 0;	/* progress counter */
767 	size_t write_total;	/* total size to actually write - excludinig
768 				   bad blocks */
769 	off_t erase_offset;	/* offset to the first erase block (aligned)
770 				   below offset */
771 	off_t block_seek;	/* offset inside the erase block to the start
772 				   of the data */
773 	off_t top_of_range;	/* end of the last block we may use */
774 	loff_t blockstart;	/* running start of the current block -
775 				   MEMGETBADBLOCK needs 64 bits */
776 	int rc;
777 
778 	blocklen = DEVESIZE (dev);
779 
780 	/* Erase sector size is always a power of 2 */
781 	top_of_range = (DEVOFFSET (dev) & ~(blocklen - 1)) +
782 		ENVSECTORS (dev) * blocklen;
783 
784 	erase_offset = offset & ~(blocklen - 1);
785 
786 	/* Maximum area we may use */
787 	erase_len = top_of_range - erase_offset;
788 
789 	blockstart = erase_offset;
790 	/* Offset inside a block */
791 	block_seek = offset - erase_offset;
792 
793 	/*
794 	 * Data size we actually have to write: from the start of the block
795 	 * to the start of the data, then count bytes of data, and to the
796 	 * end of the block
797 	 */
798 	write_total = (block_seek + count + blocklen - 1) & ~(blocklen - 1);
799 
800 	/*
801 	 * Support data anywhere within erase sectors: read out the complete
802 	 * area to be erased, replace the environment image, write the whole
803 	 * block back again.
804 	 */
805 	if (write_total > count) {
806 		data = malloc (erase_len);
807 		if (!data) {
808 			fprintf (stderr,
809 				 "Cannot malloc %u bytes: %s\n",
810 				 erase_len, strerror (errno));
811 			return -1;
812 		}
813 
814 		rc = flash_read_buf (dev, fd, data, write_total, erase_offset,
815 				     mtd_type);
816 		if (write_total != rc)
817 			return -1;
818 
819 		/* Overwrite the old environment */
820 		memcpy (data + block_seek, buf, count);
821 	} else {
822 		/*
823 		 * We get here, iff offset is block-aligned and count is a
824 		 * multiple of blocklen - see write_total calculation above
825 		 */
826 		data = buf;
827 	}
828 
829 	if (mtd_type == MTD_NANDFLASH) {
830 		/*
831 		 * NAND: calculate which blocks we are writing. We have
832 		 * to write one block at a time to skip bad blocks.
833 		 */
834 		erasesize = blocklen;
835 	} else {
836 		erasesize = erase_len;
837 	}
838 
839 	erase.length = erasesize;
840 
841 	/* This only runs once on NOR flash */
842 	while (processed < write_total) {
843 		rc = flash_bad_block (fd, mtd_type, &blockstart);
844 		if (rc < 0)		/* block test failed */
845 			return rc;
846 
847 		if (blockstart + erasesize > top_of_range) {
848 			fprintf (stderr, "End of range reached, aborting\n");
849 			return -1;
850 		}
851 
852 		if (rc) {		/* block is bad */
853 			blockstart += blocklen;
854 			continue;
855 		}
856 
857 		erase.start = blockstart;
858 		ioctl (fd, MEMUNLOCK, &erase);
859 
860 		if (ioctl (fd, MEMERASE, &erase) != 0) {
861 			fprintf (stderr, "MTD erase error on %s: %s\n",
862 				 DEVNAME (dev),
863 				 strerror (errno));
864 			return -1;
865 		}
866 
867 		if (lseek (fd, blockstart, SEEK_SET) == -1) {
868 			fprintf (stderr,
869 				 "Seek error on %s: %s\n",
870 				 DEVNAME (dev), strerror (errno));
871 			return -1;
872 		}
873 
874 #ifdef DEBUG
875 		printf ("Write 0x%x bytes at 0x%llx\n", erasesize, blockstart);
876 #endif
877 		if (write (fd, data + processed, erasesize) != erasesize) {
878 			fprintf (stderr, "Write error on %s: %s\n",
879 				 DEVNAME (dev), strerror (errno));
880 			return -1;
881 		}
882 
883 		ioctl (fd, MEMLOCK, &erase);
884 
885 		processed  += blocklen;
886 		block_seek = 0;
887 		blockstart += blocklen;
888 	}
889 
890 	if (write_total > count)
891 		free (data);
892 
893 	return processed;
894 }
895 
896 /*
897  * Set obsolete flag at offset - NOR flash only
898  */
899 static int flash_flag_obsolete (int dev, int fd, off_t offset)
900 {
901 	int rc;
902 	struct erase_info_user erase;
903 
904 	erase.start  = DEVOFFSET (dev);
905 	erase.length = DEVESIZE (dev);
906 	/* This relies on the fact, that obsolete_flag == 0 */
907 	rc = lseek (fd, offset, SEEK_SET);
908 	if (rc < 0) {
909 		fprintf (stderr, "Cannot seek to set the flag on %s \n",
910 			 DEVNAME (dev));
911 		return rc;
912 	}
913 	ioctl (fd, MEMUNLOCK, &erase);
914 	rc = write (fd, &obsolete_flag, sizeof (obsolete_flag));
915 	ioctl (fd, MEMLOCK, &erase);
916 	if (rc < 0)
917 		perror ("Could not set obsolete flag");
918 
919 	return rc;
920 }
921 
922 static int flash_write (int fd_current, int fd_target, int dev_target)
923 {
924 	int rc;
925 
926 	switch (environment.flag_scheme) {
927 	case FLAG_NONE:
928 		break;
929 	case FLAG_INCREMENTAL:
930 		(*environment.flags)++;
931 		break;
932 	case FLAG_BOOLEAN:
933 		*environment.flags = active_flag;
934 		break;
935 	default:
936 		fprintf (stderr, "Unimplemented flash scheme %u \n",
937 			 environment.flag_scheme);
938 		return -1;
939 	}
940 
941 #ifdef DEBUG
942 	printf ("Writing new environment at 0x%lx on %s\n",
943 		DEVOFFSET (dev_target), DEVNAME (dev_target));
944 #endif
945 	rc = flash_write_buf (dev_target, fd_target, environment.image,
946 			      CONFIG_ENV_SIZE, DEVOFFSET (dev_target),
947 			      DEVTYPE(dev_target));
948 	if (rc < 0)
949 		return rc;
950 
951 	if (environment.flag_scheme == FLAG_BOOLEAN) {
952 		/* Have to set obsolete flag */
953 		off_t offset = DEVOFFSET (dev_current) +
954 			offsetof (struct env_image_redundant, flags);
955 #ifdef DEBUG
956 		printf ("Setting obsolete flag in environment at 0x%lx on %s\n",
957 			DEVOFFSET (dev_current), DEVNAME (dev_current));
958 #endif
959 		flash_flag_obsolete (dev_current, fd_current, offset);
960 	}
961 
962 	return 0;
963 }
964 
965 static int flash_read (int fd)
966 {
967 	struct mtd_info_user mtdinfo;
968 	int rc;
969 
970 	rc = ioctl (fd, MEMGETINFO, &mtdinfo);
971 	if (rc < 0) {
972 		perror ("Cannot get MTD information");
973 		return -1;
974 	}
975 
976 	if (mtdinfo.type != MTD_NORFLASH && mtdinfo.type != MTD_NANDFLASH) {
977 		fprintf (stderr, "Unsupported flash type %u\n", mtdinfo.type);
978 		return -1;
979 	}
980 
981 	DEVTYPE(dev_current) = mtdinfo.type;
982 
983 	rc = flash_read_buf (dev_current, fd, environment.image, CONFIG_ENV_SIZE,
984 			     DEVOFFSET (dev_current), mtdinfo.type);
985 
986 	return (rc != CONFIG_ENV_SIZE) ? -1 : 0;
987 }
988 
989 static int flash_io (int mode)
990 {
991 	int fd_current, fd_target, rc, dev_target;
992 
993 	/* dev_current: fd_current, erase_current */
994 	fd_current = open (DEVNAME (dev_current), mode);
995 	if (fd_current < 0) {
996 		fprintf (stderr,
997 			 "Can't open %s: %s\n",
998 			 DEVNAME (dev_current), strerror (errno));
999 		return -1;
1000 	}
1001 
1002 	if (mode == O_RDWR) {
1003 		if (HaveRedundEnv) {
1004 			/* switch to next partition for writing */
1005 			dev_target = !dev_current;
1006 			/* dev_target: fd_target, erase_target */
1007 			fd_target = open (DEVNAME (dev_target), mode);
1008 			if (fd_target < 0) {
1009 				fprintf (stderr,
1010 					 "Can't open %s: %s\n",
1011 					 DEVNAME (dev_target),
1012 					 strerror (errno));
1013 				rc = -1;
1014 				goto exit;
1015 			}
1016 		} else {
1017 			dev_target = dev_current;
1018 			fd_target = fd_current;
1019 		}
1020 
1021 		rc = flash_write (fd_current, fd_target, dev_target);
1022 
1023 		if (HaveRedundEnv) {
1024 			if (close (fd_target)) {
1025 				fprintf (stderr,
1026 					"I/O error on %s: %s\n",
1027 					DEVNAME (dev_target),
1028 					strerror (errno));
1029 				rc = -1;
1030 			}
1031 		}
1032 	} else {
1033 		rc = flash_read (fd_current);
1034 	}
1035 
1036 exit:
1037 	if (close (fd_current)) {
1038 		fprintf (stderr,
1039 			 "I/O error on %s: %s\n",
1040 			 DEVNAME (dev_current), strerror (errno));
1041 		return -1;
1042 	}
1043 
1044 	return rc;
1045 }
1046 
1047 /*
1048  * s1 is either a simple 'name', or a 'name=value' pair.
1049  * s2 is a 'name=value' pair.
1050  * If the names match, return the value of s2, else NULL.
1051  */
1052 
1053 static char *envmatch (char * s1, char * s2)
1054 {
1055 
1056 	while (*s1 == *s2++)
1057 		if (*s1++ == '=')
1058 			return s2;
1059 	if (*s1 == '\0' && *(s2 - 1) == '=')
1060 		return s2;
1061 	return NULL;
1062 }
1063 
1064 /*
1065  * Prevent confusion if running from erased flash memory
1066  */
1067 int fw_env_open(void)
1068 {
1069 	int crc0, crc0_ok;
1070 	char flag0;
1071 	void *addr0;
1072 
1073 	int crc1, crc1_ok;
1074 	char flag1;
1075 	void *addr1;
1076 
1077 	struct env_image_single *single;
1078 	struct env_image_redundant *redundant;
1079 
1080 	if (parse_config ())		/* should fill envdevices */
1081 		return -1;
1082 
1083 	addr0 = calloc (1, CONFIG_ENV_SIZE);
1084 	if (addr0 == NULL) {
1085 		fprintf (stderr,
1086 			"Not enough memory for environment (%ld bytes)\n",
1087 			CONFIG_ENV_SIZE);
1088 		return -1;
1089 	}
1090 
1091 	/* read environment from FLASH to local buffer */
1092 	environment.image = addr0;
1093 
1094 	if (HaveRedundEnv) {
1095 		redundant = addr0;
1096 		environment.crc		= &redundant->crc;
1097 		environment.flags	= &redundant->flags;
1098 		environment.data	= redundant->data;
1099 	} else {
1100 		single = addr0;
1101 		environment.crc		= &single->crc;
1102 		environment.flags	= NULL;
1103 		environment.data	= single->data;
1104 	}
1105 
1106 	dev_current = 0;
1107 	if (flash_io (O_RDONLY))
1108 		return -1;
1109 
1110 	crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE);
1111 	crc0_ok = (crc0 == *environment.crc);
1112 	if (!HaveRedundEnv) {
1113 		if (!crc0_ok) {
1114 			fprintf (stderr,
1115 				"Warning: Bad CRC, using default environment\n");
1116 			memcpy(environment.data, default_environment, sizeof default_environment);
1117 		}
1118 	} else {
1119 		flag0 = *environment.flags;
1120 
1121 		dev_current = 1;
1122 		addr1 = calloc (1, CONFIG_ENV_SIZE);
1123 		if (addr1 == NULL) {
1124 			fprintf (stderr,
1125 				"Not enough memory for environment (%ld bytes)\n",
1126 				CONFIG_ENV_SIZE);
1127 			return -1;
1128 		}
1129 		redundant = addr1;
1130 
1131 		/*
1132 		 * have to set environment.image for flash_read(), careful -
1133 		 * other pointers in environment still point inside addr0
1134 		 */
1135 		environment.image = addr1;
1136 		if (flash_io (O_RDONLY))
1137 			return -1;
1138 
1139 		/* Check flag scheme compatibility */
1140 		if (DEVTYPE(dev_current) == MTD_NORFLASH &&
1141 		    DEVTYPE(!dev_current) == MTD_NORFLASH) {
1142 			environment.flag_scheme = FLAG_BOOLEAN;
1143 		} else if (DEVTYPE(dev_current) == MTD_NANDFLASH &&
1144 			   DEVTYPE(!dev_current) == MTD_NANDFLASH) {
1145 			environment.flag_scheme = FLAG_INCREMENTAL;
1146 		} else {
1147 			fprintf (stderr, "Incompatible flash types!\n");
1148 			return -1;
1149 		}
1150 
1151 		crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE);
1152 		crc1_ok = (crc1 == redundant->crc);
1153 		flag1 = redundant->flags;
1154 
1155 		if (crc0_ok && !crc1_ok) {
1156 			dev_current = 0;
1157 		} else if (!crc0_ok && crc1_ok) {
1158 			dev_current = 1;
1159 		} else if (!crc0_ok && !crc1_ok) {
1160 			fprintf (stderr,
1161 				"Warning: Bad CRC, using default environment\n");
1162 			memcpy (environment.data, default_environment,
1163 				sizeof default_environment);
1164 			dev_current = 0;
1165 		} else {
1166 			switch (environment.flag_scheme) {
1167 			case FLAG_BOOLEAN:
1168 				if (flag0 == active_flag &&
1169 				    flag1 == obsolete_flag) {
1170 					dev_current = 0;
1171 				} else if (flag0 == obsolete_flag &&
1172 					   flag1 == active_flag) {
1173 					dev_current = 1;
1174 				} else if (flag0 == flag1) {
1175 					dev_current = 0;
1176 				} else if (flag0 == 0xFF) {
1177 					dev_current = 0;
1178 				} else if (flag1 == 0xFF) {
1179 					dev_current = 1;
1180 				} else {
1181 					dev_current = 0;
1182 				}
1183 				break;
1184 			case FLAG_INCREMENTAL:
1185 				if ((flag0 == 255 && flag1 == 0) ||
1186 				    flag1 > flag0)
1187 					dev_current = 1;
1188 				else if ((flag1 == 255 && flag0 == 0) ||
1189 					 flag0 > flag1)
1190 					dev_current = 0;
1191 				else /* flags are equal - almost impossible */
1192 					dev_current = 0;
1193 				break;
1194 			default:
1195 				fprintf (stderr, "Unknown flag scheme %u \n",
1196 					 environment.flag_scheme);
1197 				return -1;
1198 			}
1199 		}
1200 
1201 		/*
1202 		 * If we are reading, we don't need the flag and the CRC any
1203 		 * more, if we are writing, we will re-calculate CRC and update
1204 		 * flags before writing out
1205 		 */
1206 		if (dev_current) {
1207 			environment.image	= addr1;
1208 			environment.crc		= &redundant->crc;
1209 			environment.flags	= &redundant->flags;
1210 			environment.data	= redundant->data;
1211 			free (addr0);
1212 		} else {
1213 			environment.image	= addr0;
1214 			/* Other pointers are already set */
1215 			free (addr1);
1216 		}
1217 	}
1218 	return 0;
1219 }
1220 
1221 
1222 static int parse_config ()
1223 {
1224 	struct stat st;
1225 
1226 #if defined(CONFIG_FILE)
1227 	/* Fills in DEVNAME(), ENVSIZE(), DEVESIZE(). Or don't. */
1228 	if (get_config (CONFIG_FILE)) {
1229 		fprintf (stderr,
1230 			"Cannot parse config file: %s\n", strerror (errno));
1231 		return -1;
1232 	}
1233 #else
1234 	strcpy (DEVNAME (0), DEVICE1_NAME);
1235 	DEVOFFSET (0) = DEVICE1_OFFSET;
1236 	ENVSIZE (0) = ENV1_SIZE;
1237 	DEVESIZE (0) = DEVICE1_ESIZE;
1238 	ENVSECTORS (0) = DEVICE1_ENVSECTORS;
1239 #ifdef HAVE_REDUND
1240 	strcpy (DEVNAME (1), DEVICE2_NAME);
1241 	DEVOFFSET (1) = DEVICE2_OFFSET;
1242 	ENVSIZE (1) = ENV2_SIZE;
1243 	DEVESIZE (1) = DEVICE2_ESIZE;
1244 	ENVSECTORS (1) = DEVICE2_ENVSECTORS;
1245 	HaveRedundEnv = 1;
1246 #endif
1247 #endif
1248 	if (stat (DEVNAME (0), &st)) {
1249 		fprintf (stderr,
1250 			"Cannot access MTD device %s: %s\n",
1251 			DEVNAME (0), strerror (errno));
1252 		return -1;
1253 	}
1254 
1255 	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
1256 		fprintf (stderr,
1257 			"Cannot access MTD device %s: %s\n",
1258 			DEVNAME (1), strerror (errno));
1259 		return -1;
1260 	}
1261 	return 0;
1262 }
1263 
1264 #if defined(CONFIG_FILE)
1265 static int get_config (char *fname)
1266 {
1267 	FILE *fp;
1268 	int i = 0;
1269 	int rc;
1270 	char dump[128];
1271 
1272 	fp = fopen (fname, "r");
1273 	if (fp == NULL)
1274 		return -1;
1275 
1276 	while (i < 2 && fgets (dump, sizeof (dump), fp)) {
1277 		/* Skip incomplete conversions and comment strings */
1278 		if (dump[0] == '#')
1279 			continue;
1280 
1281 		rc = sscanf (dump, "%s %lx %lx %lx %lx",
1282 			     DEVNAME (i),
1283 			     &DEVOFFSET (i),
1284 			     &ENVSIZE (i),
1285 			     &DEVESIZE (i),
1286 			     &ENVSECTORS (i));
1287 
1288 		if (rc < 4)
1289 			continue;
1290 
1291 		if (rc < 5)
1292 			/* Default - 1 sector */
1293 			ENVSECTORS (i) = 1;
1294 
1295 		i++;
1296 	}
1297 	fclose (fp);
1298 
1299 	HaveRedundEnv = i - 1;
1300 	if (!i) {			/* No valid entries found */
1301 		errno = EINVAL;
1302 		return -1;
1303 	} else
1304 		return 0;
1305 }
1306 #endif
1307