[3/6] incubator-mynewt-larva git commit: Allow caller to limit the number of NFFS descriptors returned for given flash area. Can be used when underlying flash has large number of small sectors.

[ma...@apache.org]

Allow caller to limit the number of NFFS descriptors returned for
given flash area. Can be used when underlying flash has large number
of small sectors.


Project: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-larva/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-larva/commit/b43cedc5
Tree: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-larva/tree/b43cedc5
Diff: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-larva/diff/b43cedc5

Branch: refs/heads/master
Commit: b43cedc52c80f6ffbec083d5b16b5de1750e1cf7
Parents: fb12884
Author: Marko Kiiskila <ma...@runtime.io>
Authored: Fri Dec 4 13:50:38 2015 -0800
Committer: Marko Kiiskila <ma...@runtime.io>
Committed: Fri Dec 4 13:50:38 2015 -0800

----------------------------------------------------------------------
 libs/util/src/flash_map.c | 48 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 8 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-mynewt-larva/blob/b43cedc5/libs/util/src/flash_map.c
----------------------------------------------------------------------
diff --git a/libs/util/src/flash_map.c b/libs/util/src/flash_map.c
index 28f26c9..9493a0d 100644
--- a/libs/util/src/flash_map.c
+++ b/libs/util/src/flash_map.c
@@ -82,35 +82,67 @@ flash_area_to_sectors(int idx, int *cnt, struct flash_area *ret)
 }
 
 #ifdef NFFS_PRESENT
+/*
+ * Turn flash region into a set of areas for NFFS use.
+ *
+ * Limit the number of regions we return to be less than *cnt.
+ * If sector count within region exceeds that, collect multiple sectors
+ * to a region.
+ */
 int
 flash_area_to_nffs_desc(int idx, int *cnt, struct nffs_area_desc *nad)
 {
-    int i;
+    int i, j;
     const struct hal_flash *hf;
     const struct flash_area *fa;
+    int max_cnt, move_on;
+    int first_idx, last_idx;
     uint32_t start, size;
+    uint32_t min_size;
 
     if (!flash_map || idx >= flash_map_entries) {
         return -1;
     }
+    first_idx = last_idx = -1;
+    max_cnt = *cnt;
     *cnt = 0;
+
     fa = &flash_map[idx];
 
     hf = bsp_flash_dev(fa->fa_flash_id);
     for (i = 0; i < hf->hf_sector_cnt; i++) {
         hf->hf_itf->hff_sector_info(i, &start, &size);
         if (start >= fa->fa_off && start < fa->fa_off + fa->fa_size) {
-            if (nad) {
-                nad->nad_flash_id = fa->fa_flash_id;
-                nad->nad_offset = start;
-                nad->nad_length = size;
-                nad++;
+            if (first_idx == -1) {
+                first_idx = i;
             }
+            last_idx = i;
             *cnt = *cnt + 1;
         }
     }
-    if (nad) {
-        memset(nad, 0, sizeof(*nad));
+    if (*cnt > max_cnt) {
+        min_size = fa->fa_size / max_cnt;
+    } else {
+        min_size = 0;
+    }
+    *cnt = 0;
+
+    move_on = 1;
+    for (i = first_idx, j = 0; i < last_idx + 1; i++) {
+        hf->hf_itf->hff_sector_info(i, &start, &size);
+        if (move_on) {
+            nad[j].nad_flash_id = fa->fa_flash_id;
+            nad[j].nad_offset = start;
+            nad[j].nad_length = size;
+            *cnt = *cnt + 1;
+            move_on = 0;
+        } else {
+            nad[j].nad_length += size;
+        }
+        if (nad[j].nad_length >= min_size) {
+            j++;
+            move_on = 1;
+        }
     }
     return 0;
 }