/* Open NVRAM and obtain a handle. */
nvram_handle_t * _nvram_open(const char *file, int rdonly)
{
int fd;
char *mtd = NULL;
nvram_handle_t *h;
nvram_header_t *header = NULL;
if( (fd = open(file ? file : mtd, O_RDWR)) > -1 )
{
char *mmap_area = (char *) mmap(
NULL, nvram_erase_size, PROT_READ | PROT_WRITE,
( rdonly == NVRAM_RO ) ? MAP_PRIVATE : MAP_SHARED, fd, 0);
if( mmap_area != MAP_FAILED )
{
if((h = (nvram_handle_t *) malloc(sizeof(nvram_handle_t))) != NULL)
{
h->fd = fd;
h->mmap = mmap_area;
h->length = nvram_erase_size;
header = nvram_header(h);
_nvram_rehash(h);
return h;
}
}
}
return NULL;
}
int nvram_commit(nvram_handle_t *h)
{
nvram_header_t *header = nvram_header(h);
char *init, *config, *refresh, *ncdl;
char *ptr, *end;
int i;
nvram_tuple_t *t;
nvram_header_t tmp;
uint8_t crc;
/* Regenerate header */
header->magic = NVRAM_MAGIC;
header->crc_ver_init = (NVRAM_VERSION << 8);
if (!(init = hash_nvram_get(h, "sdram_init")) ||
!(config = hash_nvram_get(h, "sdram_config")) ||
!(refresh = hash_nvram_get(h, "sdram_refresh")) ||
!(ncdl = hash_nvram_get(h, "sdram_ncdl"))) {
header->crc_ver_init |= SDRAM_INIT << 16;
header->config_refresh = SDRAM_CONFIG;
header->config_refresh |= SDRAM_REFRESH << 16;
header->config_ncdl = 0;
} else {
header->crc_ver_init |= (strtoul(init, NULL, 0) & 0xffff) << 16;
header->config_refresh = strtoul(config, NULL, 0) & 0xffff;
header->config_refresh |= (strtoul(refresh, NULL, 0) & 0xffff) << 16;
header->config_ncdl = strtoul(ncdl, NULL, 0);
}
/* Clear data area */
ptr = (char *) header + sizeof(nvram_header_t);
memset(ptr, 0xFF, NVRAM_SPACE - sizeof(nvram_header_t));
memset(&tmp, 0, sizeof(nvram_header_t));
/* Leave space for a double NUL at the end */
end = (char *) header + NVRAM_SPACE - 2;
/* Write out all tuples */
for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {
for (t = h->nvram_hash[i]; t; t = t->next) {
if ((ptr + strlen(t->name) + 1 + strlen(t->value) + 1) > end)
break;
ptr += sprintf(ptr, "%s=%s", t->name, t->value) + 1;
}
}
/* End with a double NULL and pad to 4 bytes */
*ptr = '\0';
ptr++;
if( (int)ptr % 4 )
memset(ptr, 0, 4 - ((int)ptr % 4));
ptr++;
/* Set new length */
header->len = NVRAM_ROUNDUP(ptr - (char *) header, 4);
/* Little-endian CRC8 over the last 11 bytes of the header */
tmp.crc_ver_init = header->crc_ver_init;
tmp.config_refresh = header->config_refresh;
tmp.config_ncdl = header->config_ncdl;
crc = hndcrc8((unsigned char *) &tmp + NVRAM_CRC_START_POSITION,
sizeof(nvram_header_t) - NVRAM_CRC_START_POSITION, 0xff);
/* Continue CRC8 over data bytes */
crc = hndcrc8((unsigned char *) &header[0] + sizeof(nvram_header_t),
header->len - sizeof(nvram_header_t), crc);
/* Set new CRC8 */
header->crc_ver_init |= crc;
/* Write out */
msync(h->mmap, h->length, MS_SYNC);
fsync(h->fd);
/* Reinitialize hash table */
return _nvram_rehash(h);
}