1 files changed, 39 insertions, 7 deletions

diff --git a/arch/mips/bcm47xx/nvram.c b/arch/mips/bcm47xx/nvram.c
index 6cf3ef29d844..b4a47fcb4f64 100644
--- a/arch/mips/bcm47xx/nvram.c
+++ b/arch/mips/bcm47xx/nvram.c
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2005 Broadcom Corporation
  * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
- * Copyright (C) 2010-2011 Hauke Mehrtens <hauke@hauke-m.de>
+ * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -23,42 +23,74 @@
 
 static char nvram_buf[NVRAM_SPACE];
 
+static u32 find_nvram_size(u32 end)
+{
+        struct nvram_header *header;
+        u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
+                header = (struct nvram_header *)KSEG1ADDR(end - nvram_sizes[i]);
+                if (header->magic == NVRAM_HEADER)
+                        return nvram_sizes[i];
+        }
+
+        return 0;
+}
+
+/* Probe for NVRAM header */
 static int nvram_find_and_copy(u32 base, u32 lim)
 {
         struct nvram_header *header;
         int i;
         u32 off;
         u32 *src, *dst;
+        u32 size;
 
         /* TODO: when nvram is on nand flash check for bad blocks first. */
         off = FLASH_MIN;
         while (off <= lim) {
                 /* Windowed flash access */
-                header = (struct nvram_header *)
-                        KSEG1ADDR(base + off - NVRAM_SPACE);
-                if (header->magic == NVRAM_HEADER)
+                size = find_nvram_size(base + off);
+                if (size) {
+                        header = (struct nvram_header *)KSEG1ADDR(base + off -
+                                                                  size);
                         goto found;
+                }
                 off <<= 1;
         }
 
         /* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
         header = (struct nvram_header *) KSEG1ADDR(base + 4096);
-        if (header->magic == NVRAM_HEADER)
+        if (header->magic == NVRAM_HEADER) {
+                size = NVRAM_SPACE;
                 goto found;
+        }
 
         header = (struct nvram_header *) KSEG1ADDR(base + 1024);
-        if (header->magic == NVRAM_HEADER)
+        if (header->magic == NVRAM_HEADER) {
+                size = NVRAM_SPACE;
                 goto found;
+        }
 
+        pr_err("no nvram found\n");
         return -ENXIO;
 
 found:
+
+        if (header->len > size)
+                pr_err("The nvram size accoridng to the header seems to be bigger than the partition on flash\n");
+        if (header->len > NVRAM_SPACE)
+                pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
+                       header->len, NVRAM_SPACE);
+
         src = (u32 *) header;
         dst = (u32 *) nvram_buf;
         for (i = 0; i < sizeof(struct nvram_header); i += 4)
                 *dst++ = *src++;
-        for (; i < header->len && i < NVRAM_SPACE; i += 4)
+        for (; i < header->len && i < NVRAM_SPACE && i < size; i += 4)
                 *dst++ = le32_to_cpu(*src++);
+        memset(dst, 0x0, NVRAM_SPACE - i);
 
         return 0;
 }