bootutil: Make boot_get_first_trailer_sector available for swap-move

This routine will now also be useful for the swap-move strategy. The
trailer size is removed from the list of parameters as it can be easily
obtained using the 'state' parameter and it will be more convenient, for
the swap-move strategy, not to have to compute it manually before
calling 'boot_get_first_trailer_sector'.

Signed-off-by: Thomas Altenbach <thomas.altenbach@legrand.com>

Author: taltenbach

boot/bootutil/src/bootutil_misc.c

@@ -397,12 +397,13 @@ boot_write_enc_key(const struct flash_area *fap, uint8_t slot,
 }
 #endif
 
-#ifdef MCUBOOT_SWAP_USING_SCRATCH
+#if defined(MCUBOOT_SWAP_USING_SCRATCH) || defined(MCUBOOT_SWAP_USING_MOVE)
 size_t
-boot_get_first_trailer_sector(struct boot_loader_state *state, size_t slot, size_t trailer_sz)
+boot_get_first_trailer_sector(struct boot_loader_state *state, size_t slot)
 {
     size_t first_trailer_sector = boot_img_num_sectors(state, slot) - 1;
     size_t sector_sz = boot_img_sector_size(state, slot, first_trailer_sector);
+    size_t trailer_sz = boot_trailer_sz(BOOT_WRITE_SZ(state));
     size_t trailer_sector_sz = sector_sz;
 
     while (trailer_sector_sz < trailer_sz) {
@@ -415,20 +416,21 @@ boot_get_first_trailer_sector(struct boot_loader_state *state, size_t slot, size
 
     return first_trailer_sector;
 }
+#endif /* MCUBOOT_SWAP_USING_SCRATCH || MCUBOOT_SWAP_USING_MOVE */
 
+#ifdef MCUBOOT_SWAP_USING_SCRATCH
 /**
  * Returns the offset to the end of the first sector of a given slot that holds image trailer data.
  *
  * @param state      Current bootloader's state.
  * @param slot       The index of the slot to consider.
- * @param trailer_sz The size of the trailer, in bytes.
  *
  * @return The offset to the end of the first sector of the slot that holds image trailer data.
  */
 static uint32_t
-get_first_trailer_sector_end_off(struct boot_loader_state *state, size_t slot, size_t trailer_sz)
+get_first_trailer_sector_end_off(struct boot_loader_state *state, size_t slot)
 {
-    size_t first_trailer_sector = boot_get_first_trailer_sector(state, slot, trailer_sz);
+    size_t first_trailer_sector = boot_get_first_trailer_sector(state, slot);
 
     return boot_img_sector_off(state, slot, first_trailer_sector) +
            boot_img_sector_size(state, slot, first_trailer_sector);
@@ -455,9 +457,9 @@ uint32_t bootutil_max_image_size(struct boot_loader_state *state, const struct f
      * trailer containing part of the trailer in the primary and secondary slot.
      */
     size_t trailer_sector_primary_end_off =
-        get_first_trailer_sector_end_off(state, BOOT_PRIMARY_SLOT, slot_trailer_sz);
+        get_first_trailer_sector_end_off(state, BOOT_PRIMARY_SLOT);
     size_t trailer_sector_secondary_end_off =
-        get_first_trailer_sector_end_off(state, BOOT_SECONDARY_SLOT, slot_trailer_sz);
+        get_first_trailer_sector_end_off(state, BOOT_SECONDARY_SLOT);
 
     size_t trailer_sz_in_first_sector;
 

boot/bootutil/src/bootutil_priv.h

@@ -365,19 +365,18 @@ int boot_read_enc_key(const struct flash_area *fap, uint8_t slot,
                       struct boot_status *bs);
 #endif
 
-#ifdef MCUBOOT_SWAP_USING_SCRATCH
+#if defined(MCUBOOT_SWAP_USING_SCRATCH) || defined(MCUBOOT_SWAP_USING_MOVE)
 /**
  * Finds the first sector of a given slot that holds image trailer data.
  *
  * @param state      Current bootloader's state.
  * @param slot       The index of the slot to consider.
- * @param trailer_sz The size of the trailer, in bytes.
  *
  * @return The index of the first sector of the slot that holds image trailer data.
  */
 size_t
-boot_get_first_trailer_sector(struct boot_loader_state *state, size_t slot, size_t trailer_sz);
-#endif
+boot_get_first_trailer_sector(struct boot_loader_state *state, size_t slot);
+#endif /* MCUBOOT_SWAP_USING_SCRATCH || MCUBOOT_SWAP_USING_MOVE */
 
 /**
  * Checks that a buffer is erased according to what the erase value for the

boot/bootutil/src/swap_scratch.c

@@ -592,8 +592,7 @@ boot_swap_sectors(int idx, uint32_t sz, struct boot_loader_state *state,
      * NOTE: `use_scratch` is a temporary flag (never written to flash) which
      * controls if special handling is needed (swapping the first trailer sector).
      */
-    first_trailer_sector_primary =
-        boot_get_first_trailer_sector(state, BOOT_PRIMARY_SLOT, trailer_sz);
+    first_trailer_sector_primary = boot_get_first_trailer_sector(state, BOOT_PRIMARY_SLOT);
 
     /* Check if the currently swapped sector(s) contain the trailer or part of it */
     if ((img_off + sz) >
@@ -673,7 +672,7 @@ boot_swap_sectors(int idx, uint32_t sz, struct boot_loader_state *state,
                  * sector(s) containing the beginning of the trailer won't be erased again.
                  */
                 size_t trailer_sector_secondary =
-                    boot_get_first_trailer_sector(state, BOOT_SECONDARY_SLOT, trailer_sz);
+                    boot_get_first_trailer_sector(state, BOOT_SECONDARY_SLOT);
 
                 uint32_t trailer_sector_offset =
                     boot_img_sector_off(state, BOOT_SECONDARY_SLOT, trailer_sector_secondary);