2 * NVRAM variable manipulation (common)
4 * Copyright 2004, Broadcom Corporation
5 * Copyright 2009-2010, OpenWrt.org
8 * THIS SOFTWARE IS OFFERED "AS IS", AND BROADCOM GRANTS NO WARRANTIES OF ANY
9 * KIND, EXPRESS OR IMPLIED, BY STATUTE, COMMUNICATION OR OTHERWISE. BROADCOM
10 * SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS
11 * FOR A SPECIFIC PURPOSE OR NONINFRINGEMENT CONCERNING THIS SOFTWARE.
18 printf("%s(%i) in %s(): %s\n", \
19 __FILE__, __LINE__, __FUNCTION__, msg ? msg : "?")
21 /* Size of "nvram" MTD partition */
22 size_t nvram_part_size = 0;
26 * -- Helper functions --
30 static uint32_t hash(const char *s)
35 hash = 31 * hash + *s++;
40 /* Free all tuples. */
41 static void _nvram_free(nvram_handle_t *h)
44 nvram_tuple_t *t, *next;
47 for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
48 for (t = h->nvram_hash[i]; t; t = next) {
52 h->nvram_hash[i] = NULL;
56 for (t = h->nvram_dead; t; t = next) {
64 /* (Re)allocate NVRAM tuples. */
65 static nvram_tuple_t * _nvram_realloc( nvram_handle_t *h, nvram_tuple_t *t,
66 const char *name, const char *value )
68 if ((strlen(value) + 1) > NVRAM_SPACE)
72 if (!(t = malloc(sizeof(nvram_tuple_t) + strlen(name) + 1)))
76 t->name = (char *) &t[1];
77 strcpy(t->name, name);
83 if (!t->value || strcmp(t->value, value))
85 if(!(t->value = (char *) realloc(t->value, strlen(value)+1)))
88 strcpy(t->value, value);
89 t->value[strlen(value)] = '\0';
95 /* (Re)initialize the hash table. */
96 static int _nvram_rehash(nvram_handle_t *h)
98 nvram_header_t *header = nvram_header(h);
99 char buf[] = "0xXXXXXXXX", *name, *value, *eq;
101 /* (Re)initialize hash table */
104 /* Parse and set "name=value\0 ... \0\0" */
105 name = (char *) &header[1];
107 for (; *name; name = value + strlen(value) + 1) {
108 if (!(eq = strchr(name, '=')))
112 nvram_set(h, name, value);
116 /* Set special SDRAM parameters */
117 if (!nvram_get(h, "sdram_init")) {
118 sprintf(buf, "0x%04X", (uint16_t)(header->crc_ver_init >> 16));
119 nvram_set(h, "sdram_init", buf);
121 if (!nvram_get(h, "sdram_config")) {
122 sprintf(buf, "0x%04X", (uint16_t)(header->config_refresh & 0xffff));
123 nvram_set(h, "sdram_config", buf);
125 if (!nvram_get(h, "sdram_refresh")) {
126 sprintf(buf, "0x%04X",
127 (uint16_t)((header->config_refresh >> 16) & 0xffff));
128 nvram_set(h, "sdram_refresh", buf);
130 if (!nvram_get(h, "sdram_ncdl")) {
131 sprintf(buf, "0x%08X", header->config_ncdl);
132 nvram_set(h, "sdram_ncdl", buf);
140 * -- Public functions --
143 /* Get nvram header. */
144 nvram_header_t * nvram_header(nvram_handle_t *h)
146 return (nvram_header_t *) &h->mmap[h->offset];
149 /* Get the value of an NVRAM variable. */
150 char * nvram_get(nvram_handle_t *h, const char *name)
160 i = hash(name) % NVRAM_ARRAYSIZE(h->nvram_hash);
162 /* Find the associated tuple in the hash table */
163 for (t = h->nvram_hash[i]; t && strcmp(t->name, name); t = t->next);
165 value = t ? t->value : NULL;
170 /* Set the value of an NVRAM variable. */
171 int nvram_set(nvram_handle_t *h, const char *name, const char *value)
174 nvram_tuple_t *t, *u, **prev;
177 i = hash(name) % NVRAM_ARRAYSIZE(h->nvram_hash);
179 /* Find the associated tuple in the hash table */
180 for (prev = &h->nvram_hash[i], t = *prev;
181 t && strcmp(t->name, name); prev = &t->next, t = *prev);
183 /* (Re)allocate tuple */
184 if (!(u = _nvram_realloc(h, t, name, value)))
185 return -12; /* -ENOMEM */
187 /* Value reallocated */
191 /* Move old tuple to the dead table */
194 t->next = h->nvram_dead;
198 /* Add new tuple to the hash table */
199 u->next = h->nvram_hash[i];
200 h->nvram_hash[i] = u;
205 /* Unset the value of an NVRAM variable. */
206 int nvram_unset(nvram_handle_t *h, const char *name)
209 nvram_tuple_t *t, **prev;
215 i = hash(name) % NVRAM_ARRAYSIZE(h->nvram_hash);
217 /* Find the associated tuple in the hash table */
218 for (prev = &h->nvram_hash[i], t = *prev;
219 t && strcmp(t->name, name); prev = &t->next, t = *prev);
221 /* Move it to the dead table */
224 t->next = h->nvram_dead;
231 /* Get all NVRAM variables. */
232 nvram_tuple_t * nvram_getall(nvram_handle_t *h)
235 nvram_tuple_t *t, *l, *x;
239 for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
240 for (t = h->nvram_hash[i]; t; t = t->next) {
241 if( (x = (nvram_tuple_t *) malloc(sizeof(nvram_tuple_t))) != NULL )
258 /* Regenerate NVRAM. */
259 int nvram_commit(nvram_handle_t *h)
261 nvram_header_t *header = nvram_header(h);
262 char *init, *config, *refresh, *ncdl;
269 /* Regenerate header */
270 header->magic = NVRAM_MAGIC;
271 header->crc_ver_init = (NVRAM_VERSION << 8);
272 if (!(init = nvram_get(h, "sdram_init")) ||
273 !(config = nvram_get(h, "sdram_config")) ||
274 !(refresh = nvram_get(h, "sdram_refresh")) ||
275 !(ncdl = nvram_get(h, "sdram_ncdl"))) {
276 header->crc_ver_init |= SDRAM_INIT << 16;
277 header->config_refresh = SDRAM_CONFIG;
278 header->config_refresh |= SDRAM_REFRESH << 16;
279 header->config_ncdl = 0;
281 header->crc_ver_init |= (strtoul(init, NULL, 0) & 0xffff) << 16;
282 header->config_refresh = strtoul(config, NULL, 0) & 0xffff;
283 header->config_refresh |= (strtoul(refresh, NULL, 0) & 0xffff) << 16;
284 header->config_ncdl = strtoul(ncdl, NULL, 0);
287 /* Clear data area */
288 ptr = (char *) header + sizeof(nvram_header_t);
289 memset(ptr, 0xFF, NVRAM_SPACE - sizeof(nvram_header_t));
290 memset(&tmp, 0, sizeof(nvram_header_t));
292 /* Leave space for a double NUL at the end */
293 end = (char *) header + NVRAM_SPACE - 2;
295 /* Write out all tuples */
296 for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
297 for (t = h->nvram_hash[i]; t; t = t->next) {
298 if ((ptr + strlen(t->name) + 1 + strlen(t->value) + 1) > end)
300 ptr += sprintf(ptr, "%s=%s", t->name, t->value) + 1;
304 /* End with a double NULL and pad to 4 bytes */
309 memset(ptr, 0, 4 - ((int)ptr % 4));
314 header->len = NVRAM_ROUNDUP(ptr - (char *) header, 4);
316 /* Little-endian CRC8 over the last 11 bytes of the header */
317 tmp.crc_ver_init = header->crc_ver_init;
318 tmp.config_refresh = header->config_refresh;
319 tmp.config_ncdl = header->config_ncdl;
320 crc = hndcrc8((unsigned char *) &tmp + NVRAM_CRC_START_POSITION,
321 sizeof(nvram_header_t) - NVRAM_CRC_START_POSITION, 0xff);
323 /* Continue CRC8 over data bytes */
324 crc = hndcrc8((unsigned char *) &header[0] + sizeof(nvram_header_t),
325 header->len - sizeof(nvram_header_t), crc);
328 header->crc_ver_init |= crc;
331 msync(h->mmap, h->length, MS_SYNC);
334 /* Reinitialize hash table */
335 return _nvram_rehash(h);
338 /* Open NVRAM and obtain a handle. */
339 nvram_handle_t * nvram_open(const char *file, int rdonly)
345 nvram_header_t *header;
348 /* If erase size or file are undefined then try to define them */
349 if( (nvram_part_size == 0) || (file == NULL) )
351 /* Finding the mtd will set the appropriate erase size */
352 if( (mtd = nvram_find_mtd()) == NULL || nvram_part_size == 0 )
359 if( (fd = open(file ? file : mtd, O_RDWR)) > -1 )
361 char *mmap_area = (char *) mmap(
362 NULL, nvram_part_size, PROT_READ | PROT_WRITE,
363 (( rdonly == NVRAM_RO ) ? MAP_PRIVATE : MAP_SHARED) | MAP_LOCKED, fd, 0);
365 if( mmap_area != MAP_FAILED )
368 * Start looking for NVRAM_MAGIC at beginning of MTD
369 * partition. Stop if there is less than NVRAM_MIN_SPACE
370 * to check, that was the lowest used size.
372 for( i = 0; i <= ((nvram_part_size - NVRAM_MIN_SPACE) / sizeof(uint32_t)); i++ )
374 if( ((uint32_t *)mmap_area)[i] == NVRAM_MAGIC )
376 offset = i * sizeof(uint32_t);
386 else if( (h = malloc(sizeof(nvram_handle_t))) != NULL )
388 memset(h, 0, sizeof(nvram_handle_t));
392 h->length = nvram_part_size;
395 header = nvram_header(h);
397 if (header->magic == NVRAM_MAGIC &&
398 (rdonly || header->len < NVRAM_SPACE)) {
405 munmap(h->mmap, h->length);
416 /* Close NVRAM and free memory. */
417 int nvram_close(nvram_handle_t *h)
420 munmap(h->mmap, h->length);
427 /* Determine NVRAM device node. */
428 char * nvram_find_mtd(void)
436 if ((fp = fopen("/proc/mtd", "r")))
438 while( fgets(dev, sizeof(dev), fp) )
440 if( strstr(dev, "nvram") && sscanf(dev, "mtd%d: %08x", &i, &part_size) )
442 nvram_part_size = part_size;
444 sprintf(dev, "/dev/mtdblock%d", i);
445 if( stat(dev, &s) > -1 && (s.st_mode & S_IFBLK) )
447 if( (path = (char *) malloc(strlen(dev)+1)) != NULL )
449 strncpy(path, dev, strlen(dev)+1);
461 /* Check NVRAM staging file. */
462 char * nvram_find_staging(void)
466 if( (stat(NVRAM_STAGING, &s) > -1) && (s.st_mode & S_IFREG) )
468 return NVRAM_STAGING;
474 /* Copy NVRAM contents to staging file. */
475 int nvram_to_staging(void)
477 int fdmtd, fdstg, stat;
478 char *mtd = nvram_find_mtd();
479 char buf[nvram_part_size];
483 if( (mtd != NULL) && (nvram_part_size > 0) )
485 if( (fdmtd = open(mtd, O_RDONLY)) > -1 )
487 if( read(fdmtd, buf, sizeof(buf)) == sizeof(buf) )
489 if((fdstg = open(NVRAM_STAGING, O_WRONLY | O_CREAT, 0600)) > -1)
491 write(fdstg, buf, sizeof(buf));
507 /* Copy staging file to NVRAM device. */
508 int staging_to_nvram(void)
510 int fdmtd, fdstg, stat;
511 char *mtd = nvram_find_mtd();
512 char buf[nvram_part_size];
516 if( (mtd != NULL) && (nvram_part_size > 0) )
518 if( (fdstg = open(NVRAM_STAGING, O_RDONLY)) > -1 )
520 if( read(fdstg, buf, sizeof(buf)) == sizeof(buf) )
522 if( (fdmtd = open(mtd, O_WRONLY | O_SYNC)) > -1 )
524 write(fdmtd, buf, sizeof(buf));
534 stat = unlink(NVRAM_STAGING) ? 1 : 0;