commit e24534799b301378babc6245b18d9fbd1f7c7ebf
author David Vincze <david.vincze@arm.com> Mon Jun 17 12:31:59 2019 +0200
committer David Brown <davidb@davidb.org> Tue Jul 23 09:11:34 2019 -0500
tree 23607c3bfb5568149ac0be2bd241000b4453732d
parent 853657c23d385fd105b72833c8c0cfb2a82a45a2

Boot: Save image sequence number to image trailer

Overload the swap_type field in image trailer to store as an addition
the image sequence number. It indicates which image's swap was
interrupted. It is required by multi image boot to determine which
image the trailer belongs to if boot status is found on scratch area
when the swap operation is resumed.

Change-Id: I6820fd8277931aff4f0db408376eae8b42a030ed
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Signed-off-by: David Vincze <david.vincze@arm.com>

boot/bootutil/src/bootutil_misc.c

diff --git a/boot/bootutil/src/bootutil_misc.c b/boot/bootutil/src/bootutil_misc.c
index 8cab4c4..041f6a2 100644
--- a/boot/bootutil/src/bootutil_misc.c
+++ b/boot/bootutil/src/bootutil_misc.c
@@ -17,6 +17,10 @@
  * under the License.
  */
 
+/*
+ * Modifications are Copyright (c) 2019 Arm Limited.
+ */
+
 #include <assert.h>
 #include <string.h>
 #include <inttypes.h>
@@ -194,7 +198,7 @@
 }
 
 uint32_t
-boot_swap_type_off(const struct flash_area *fap)
+boot_swap_info_off(const struct flash_area *fap)
 {
     return fap->fa_size - BOOT_MAGIC_SZ - BOOT_MAX_ALIGN * 3;
 }
@@ -232,6 +236,7 @@
 {
     uint32_t magic[BOOT_MAGIC_ARR_SZ];
     uint32_t off;
+    uint8_t swap_info;
     int rc;
 
     off = boot_magic_off(fap);
@@ -245,14 +250,19 @@
         state->magic = boot_magic_decode(magic);
     }
 
-    off = boot_swap_type_off(fap);
-    rc = flash_area_read_is_empty(fap, off, &state->swap_type,
-            sizeof state->swap_type);
+    off = boot_swap_info_off(fap);
+    rc = flash_area_read_is_empty(fap, off, &swap_info, sizeof swap_info);
     if (rc < 0) {
         return BOOT_EFLASH;
     }
+
+    /* Extract the swap type and image number */
+    state->swap_type = BOOT_GET_SWAP_TYPE(swap_info);
+    state->image_num = BOOT_GET_IMAGE_NUM(swap_info);
+
     if (rc == 1 || state->swap_type > BOOT_SWAP_TYPE_REVERT) {
         state->swap_type = BOOT_SWAP_TYPE_NONE;
+        state->image_num = 0;
     }
 
     off = boot_copy_done_off(fap);
@@ -494,14 +504,18 @@
  * resume in case of an unexpected reset.
  */
 int
-boot_write_swap_type(const struct flash_area *fap, uint8_t swap_type)
+boot_write_swap_info(const struct flash_area *fap, uint8_t swap_type,
+                     uint8_t image_num)
 {
     uint32_t off;
+    uint8_t swap_info;
 
-    off = boot_swap_type_off(fap);
-    BOOT_LOG_DBG("writing swap_type; fa_id=%d off=0x%x (0x%x), swap_type=0x%x",
-                 fap->fa_id, off, fap->fa_off + off, swap_type);
-    return boot_write_trailer_byte(fap, off, swap_type);
+    BOOT_SET_SWAP_INFO(swap_info, image_num, swap_type);
+    off = boot_swap_info_off(fap);
+    BOOT_LOG_DBG("writing swap_info; fa_id=%d off=0x%x (0x%x), swap_type=0x%x"
+                 " image_num=0x%x",
+                 fap->fa_id, off, fap->fa_off + off, swap_type, image_num);
+    return boot_write_trailer_byte(fap, off, swap_info);
 }
 
 int
@@ -648,7 +662,7 @@
             } else {
                 swap_type = BOOT_SWAP_TYPE_TEST;
             }
-            rc = boot_write_swap_type(fap, swap_type);
+            rc = boot_write_swap_info(fap, swap_type, 0);
         }
 
         flash_area_close(fap);