From bce989eb57cf23b6f72bcc28afe82b5854fffff8 Mon Sep 17 00:00:00 2001
From: Peter Andersson <pelleplutt1976@gmail.com>
Date: Mon, 23 Mar 2015 22:21:24 +0100
Subject: [PATCH] Struct alignment needed for some targets, define in
 spiffs_config #10

Added config define SPIFFS_ALIGNED_OBJECT_INDEX_TABLES, default
disabled
---
 src/default/spiffs_config.h | 7 ++++++-
 src/spiffs_nucleus.h        | 8 +++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/default/spiffs_config.h b/src/default/spiffs_config.h
index 33a712e..169a88f 100644
--- a/src/default/spiffs_config.h
+++ b/src/default/spiffs_config.h
@@ -151,7 +151,12 @@
 #endif
 #endif
 
-// Set SPFIFS_TEST_VISUALISATION to non-zero to enable SPIFFS_vis function
+// Enable this if your target needs aligned data for index tables
+#ifndef SPIFFS_ALIGNED_OBJECT_INDEX_TABLES
+#define SPIFFS_ALIGNED_OBJECT_INDEX_TABLES       0
+#endif
+
+// Set SPIFFS_TEST_VISUALISATION to non-zero to enable SPIFFS_vis function
 // in the api. This function will visualize all filesystem using given printf
 // function.
 #ifndef SPIFFS_TEST_VISUALISATION
diff --git a/src/spiffs_nucleus.h b/src/spiffs_nucleus.h
index 01a1f05..a8e30b7 100644
--- a/src/spiffs_nucleus.h
+++ b/src/spiffs_nucleus.h
@@ -381,6 +381,8 @@ typedef struct {
 // object structs
 
 // page header, part of each page except object lookup pages
+// NB: this is always aligned when the data page is an object index,
+// as in this case struct spiffs_page_object_ix is used
 typedef struct __attribute(( packed )) {
   // object id
   spiffs_obj_id obj_id;
@@ -391,7 +393,11 @@ typedef struct __attribute(( packed )) {
 } spiffs_page_header;
 
 // object index header page header
-typedef struct __attribute(( packed )) {
+typedef struct __attribute(( packed ))
+#if SPIFFS_ALIGNED_OBJECT_INDEX_TABLES
+                __attribute(( aligned(sizeof(spiffs_page_ix)) ))
+#endif
+{
   // common page header
   spiffs_page_header p_hdr;
   // alignment