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-rw-r--r--package/nvram/src/nvram.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/package/nvram/src/nvram.c b/package/nvram/src/nvram.c
index 7ab8c81..a0bc006 100644
--- a/package/nvram/src/nvram.c
+++ b/package/nvram/src/nvram.c
@@ -142,7 +142,7 @@ static int _nvram_rehash(nvram_handle_t *h)
/* Get nvram header. */
nvram_header_t * nvram_header(nvram_handle_t *h)
{
- return (nvram_header_t *) &h->mmap[NVRAM_START(nvram_erase_size)];
+ return (nvram_header_t *) &h->mmap[h->offset];
}
/* Get the value of an NVRAM variable. */
@@ -337,10 +337,12 @@ int nvram_commit(nvram_handle_t *h)
/* Open NVRAM and obtain a handle. */
nvram_handle_t * nvram_open(const char *file, int rdonly)
{
+ int i;
int fd;
char *mtd = NULL;
nvram_handle_t *h;
nvram_header_t *header;
+ int offset = -1;
/* If erase size or file are undefined then try to define them */
if( (nvram_erase_size == 0) || (file == NULL) )
@@ -361,15 +363,28 @@ nvram_handle_t * nvram_open(const char *file, int rdonly)
if( mmap_area != MAP_FAILED )
{
- memset(mmap_area, 0xFF, NVRAM_START(nvram_erase_size));
+ for( i = 0; i <= ((nvram_erase_size - NVRAM_SPACE) / sizeof(uint32_t)); i++ )
+ {
+ if( ((uint32_t *)mmap_area)[i] == NVRAM_MAGIC )
+ {
+ offset = i * sizeof(uint32_t);
+ break;
+ }
+ }
- if((h = (nvram_handle_t *) malloc(sizeof(nvram_handle_t))) != NULL)
+ if( offset < 0 )
+ {
+ free(mtd);
+ return NULL;
+ }
+ else if( (h = malloc(sizeof(nvram_handle_t))) != NULL )
{
memset(h, 0, sizeof(nvram_handle_t));
h->fd = fd;
h->mmap = mmap_area;
h->length = nvram_erase_size;
+ h->offset = offset;
header = nvram_header(h);