From: rmilecki <rmilecki@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Fri, 24 Apr 2015 14:28:57 +0000 (+0000)
Subject: nvram: fix regression in finding NVRAM beginning
X-Git-Url: https://git.archive.openwrt.org/?p=openwrt.git;a=commitdiff_plain;h=93475f157291bc2224be07a508154d63e32796e7

nvram: fix regression in finding NVRAM beginning

The loop was giving up too early as it never expected NVRAM smaller
than 0x10000.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45578 3c298f89-4303-0410-b956-a3cf2f4a3e73
---

diff --git a/package/utils/nvram/src/nvram.c b/package/utils/nvram/src/nvram.c
index 0e1c726837..c4bcb1d4a6 100644
--- a/package/utils/nvram/src/nvram.c
+++ b/package/utils/nvram/src/nvram.c
@@ -364,7 +364,12 @@ nvram_handle_t * nvram_open(const char *file, int rdonly)
 
 		if( mmap_area != MAP_FAILED )
 		{
-			for( i = 0; i <= ((nvram_part_size - NVRAM_SPACE) / sizeof(uint32_t)); i++ )
+			/*
+			 * Start looking for NVRAM_MAGIC at beginning of MTD
+			 * partition. Stop if there is less than NVRAM_MIN_SPACE
+			 * to check, that was the lowest used size.
+			 */
+			for( i = 0; i <= ((nvram_part_size - NVRAM_MIN_SPACE) / sizeof(uint32_t)); i++ )
 			{
 				if( ((uint32_t *)mmap_area)[i] == NVRAM_MAGIC )
 				{
diff --git a/package/utils/nvram/src/nvram.h b/package/utils/nvram/src/nvram.h
index cd37650860..215d816327 100644
--- a/package/utils/nvram/src/nvram.h
+++ b/package/utils/nvram/src/nvram.h
@@ -113,6 +113,7 @@ char * nvram_find_staging(void);
 #define	NVRAM_ROUNDUP(x, y)	((((x)+((y)-1))/(y))*(y))
 
 /* NVRAM constants */
+#define NVRAM_MIN_SPACE			0x8000
 #define NVRAM_SPACE			0x10000
 #define NVRAM_MAGIC			0x48534C46	/* 'FLSH' */
 #define NVRAM_VERSION		1