+static int tplink_check_rootfs_magic(struct mtd_info *mtd, size_t offset)
+{
+ u32 magic;
+ size_t retlen;
+ int ret;
+
+ ret = mtd->read(mtd, offset, sizeof(magic), &retlen,
+ (unsigned char *) &magic);
+ if (ret)
+ return ret;
+
+ if (retlen != sizeof(magic))
+ return -EIO;
+
+ if (le32_to_cpu(magic) != SQUASHFS_MAGIC &&
+ magic != 0x19852003)
+ return -EINVAL;
+
+ return 0;
+}
+