[nrf noup] loader: Do not write trailer for NSIB images

The NSIB does not check the MCUboot image trailer. Writing data to it
(i.e. copy done or image ok flags) artificially limits the maximum size
of the MCUboot image that can be provided.

Ref: NCSDK-39564

Signed-off-by: Tomasz Chyrowicz <tomasz.chyrowicz@nordicsemi.no>
(cherry picked from commit 69c7ba7)

Author: tomchy

boot/bootutil/src/loader.c

@@ -1718,8 +1718,8 @@ boot_perform_update(struct boot_loader_state *state, struct boot_status *bs)
      * swap was finished to avoid a new revert.
      */
     swap_type = BOOT_SWAP_TYPE(state);
-    if (swap_type == BOOT_SWAP_TYPE_REVERT ||
-            swap_type == BOOT_SWAP_TYPE_PERM) {
+    if ((swap_type == BOOT_SWAP_TYPE_REVERT || swap_type == BOOT_SWAP_TYPE_PERM)
+        && (!IS_NSIB_OWNED(BOOT_CURR_IMG(state)))) {
         rc = swap_set_image_ok(BOOT_CURR_IMG(state));
         if (rc != 0) {
             BOOT_SWAP_TYPE(state) = swap_type = BOOT_SWAP_TYPE_PANIC;
@@ -1746,7 +1746,7 @@ boot_perform_update(struct boot_loader_state *state, struct boot_status *bs)
     }
 #endif /* MCUBOOT_HW_ROLLBACK_PROT */
 
-    if (BOOT_IS_UPGRADE(swap_type)) {
+    if (BOOT_IS_UPGRADE(swap_type) && (!IS_NSIB_OWNED(BOOT_CURR_IMG(state)))) {
         rc = swap_set_copy_done(BOOT_CURR_IMG(state));
         if (rc != 0) {
             BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
@@ -1782,8 +1782,8 @@ boot_complete_partial_swap(struct boot_loader_state *state,
     /* The following states need image_ok be explicitly set after the
      * swap was finished to avoid a new revert.
      */
-    if (bs->swap_type == BOOT_SWAP_TYPE_REVERT ||
-        bs->swap_type == BOOT_SWAP_TYPE_PERM) {
+    if ((bs->swap_type == BOOT_SWAP_TYPE_REVERT || bs->swap_type == BOOT_SWAP_TYPE_PERM)
+        && (!IS_NSIB_OWNED(BOOT_CURR_IMG(state)))) {
         rc = swap_set_image_ok(BOOT_CURR_IMG(state));
         if (rc != 0) {
             BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
@@ -2332,10 +2332,12 @@ context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp)
              * pretending we just reverted back to primary slot.
              */
 #ifndef MCUBOOT_OVERWRITE_ONLY
-            /* image_ok needs to be explicitly set to avoid a new revert. */
-            rc = swap_set_image_ok(BOOT_CURR_IMG(state));
-            if (rc != 0) {
-                BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
+            if (!IS_NSIB_OWNED(BOOT_CURR_IMG(state))) {
+                /* image_ok needs to be explicitly set to avoid a new revert. */
+                rc = swap_set_image_ok(BOOT_CURR_IMG(state));
+                if (rc != 0) {
+                    BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_PANIC;
+                }
             }
 #endif /* !MCUBOOT_OVERWRITE_ONLY */
             break;