commit 4649072b1b33d5e3f704badf76e5d7bf040d6f59
author Fabio Utzig <utzig@apache.org> Mon Sep 04 15:34:32 2017 -0300
committer David Brown <davidb@davidb.org> Wed Sep 06 16:16:58 2017 -0600
tree c5091e1e7fa4105bf291c7a6dfffe9311aa48ae0
parent 2eebf110ddef0ba0896d9c5584aff721b44d2f5d

Adds total size of a swap to the trailer

When starting a swap upgrade, the total size of data to be swapped is
calculated only at the beginning and saved to the trailer. This avoids
having to use complicated heuristics to find the total swap size, which
might depend on data that was already moved. When resuming a swap, the
size is found in the trailer and used.

Also includes some small comment fixes and refactors.

Signed-off-by: Fabio Utzig <utzig@apache.org>
Signed-off-by: David Brown <david.brown@linaro.org>

boot/bootutil/src/bootutil_priv.h

diff --git a/boot/bootutil/src/bootutil_priv.h b/boot/bootutil/src/bootutil_priv.h
index 3530338..c1cf779 100644
--- a/boot/bootutil/src/bootutil_priv.h
+++ b/boot/bootutil/src/bootutil_priv.h
@@ -47,6 +47,7 @@
     uint32_t idx;         /* Which area we're operating on */
     uint8_t state;        /* Which part of the swapping process are we at */
     uint8_t use_scratch;  /* Are status bytes ever written to scratch? */
+    uint32_t swap_size;   /* Total size of swapped image */
 };
 
 #define BOOT_MAGIC_GOOD  1
@@ -59,15 +60,19 @@
  *  0                   1                   2                   3
  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * ~                        MAGIC (16 octets)                      ~
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  * ~                                                               ~
  * ~                Swap status (variable, aligned)                ~
  * ~                                                               ~
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * |   Copy done   |     0xff padding (up to min-write-sz - 1)     ~
+ * |                          Swap size                            |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * |   Image OK    |     0xff padding (up to min-write-sz - 1)     ~
+ * ~                  0xff padding (MAX ALIGN - 4)                 ~
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |   Copy done   |          0xff padding (MAX ALIGN - 1)         ~
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |   Image OK    |          0xff padding (MAX ALIGN - 1)         ~
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * ~                        MAGIC (16 octets)                      ~
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  */
 
@@ -140,6 +145,8 @@
 int boot_schedule_test_swap(void);
 int boot_write_copy_done(const struct flash_area *fap);
 int boot_write_image_ok(const struct flash_area *fap);
+int boot_write_swap_size(const struct flash_area *fap, uint32_t swap_size);
+int boot_read_swap_size(uint32_t *swap_size);
 
 /*
  * Accessors for the contents of struct boot_loader_state.