diff --git a/boot/bootutil/include/bootutil/boot_hooks.h b/boot/bootutil/include/bootutil/boot_hooks.h
new file mode 100644
index 0000000..a94c5de
--- /dev/null
+++ b/boot/bootutil/include/bootutil/boot_hooks.h
@@ -0,0 +1,122 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2021 Nordic Semiconductor ASA
+ *
+ * Original license:
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * @file
+ * @brief Hooks definition implementation API
+ *
+ * This file contains API interface definition for hooks which can be
+ * implemented to overide or to amend some of MCUboot's native routines.
+ */
+
+#ifndef H_BOOTUTIL_HOOKS
+#define H_BOOTUTIL_HOOKS
+
+#ifdef MCUBOOT_IMAGE_ACCESS_HOOKS
+
+#define BOOT_HOOK_CALL(f, ret_default, ...) f(__VA_ARGS__)
+
+#define BOOT_HOOK_CALL_FIH(f, fih_ret_default, fih_rc, ...) \
+    do { \
+        FIH_CALL(f, fih_rc, __VA_ARGS__); \
+    } while(0);
+
+#else
+
+#define BOOT_HOOK_CALL(f, ret_default, ...) ret_default
+
+#define BOOT_HOOK_CALL_FIH(f, fih_ret_default, fih_rc, ...) \
+    do { \
+        fih_rc = fih_ret_default; \
+    } while(0);
+
+#endif
+
+/** Hook for provide image header data.
+ *
+ * This Hook may be used to overide image header read implementation or doing
+ * a custom action before.
+ *
+ * @param img_index the index of the image pair
+ * @param slot slot number
+ * @param img_head image header structure to be populated
+ *
+ * @retval 0: header was read/populated, skip direct header data read
+ *         BOOT_HOOK_REGULAR: follow the normal execution path,
+ *         otherwise an error-code value.
+ */
+int boot_read_image_header_hook(int img_index, int slot,
+                                struct image_header *img_head);
+
+/** Hook for Validate image hash/signature
+ *
+ * This Hook may be used to overide image validation procedure or doing
+ * a custom action before.
+ *
+ * @param img_index the index of the image pair
+ * @param slot slot number
+ * 
+ * @retval FIH_SUCCESS: image is valid, skip direct validation
+ *         FIH_FAILURE: image is invalid, skip direct validation
+ *         fih encoded BOOT_HOOK_REGULAR: follow the normal execution path.
+ */
+fih_int boot_image_check_hook(int img_index, int slot);
+
+/** Hook for implement image update
+ *
+ * This hook is for for implementing an alternative mechanism of image update or
+ * doing a custom action before.
+ *
+ * @param img_index the index of the image pair
+ * @param img_head the image header of the secondary image
+ * @param area the flash area of the secondary image.
+ *
+ * @retval 0: update was done, skip performing the update
+ *         BOOT_HOOK_REGULAR: follow the normal execution path,
+ *         otherwise an error-code value.
+ */
+int boot_perform_update_hook(int img_index, struct image_header *img_head,
+                             const struct flash_area *area);
+
+/** Hook for implement image's post copying action
+ *
+ * This hook is for implement action which might be done right after image was
+ * copied to the primary slot. This hook is called in MCUBOOT_OVERWRITE_ONLY
+ * mode only.
+ *
+ * @param img_index the index of the image pair
+ * @param area the flash area of the primary image.
+ * @param size size of copied image.
+ *
+ * @retval 0: success, mcuboot will follow normal code execution flow after
+ *            execution of this call.
+ *         non-zero: an error, mcuboot will return from
+ *         boot_copy_image() with error.
+ *         Update will be undone so might be resume on the next boot.
+ */
+int boot_copy_region_post_hook(int img_index, const struct flash_area *area,
+                               size_t size);
+
+#endif /*H_BOOTUTIL_HOOKS*/
diff --git a/boot/bootutil/include/bootutil/bootutil_public.h b/boot/bootutil/include/bootutil/bootutil_public.h
index 60aeef0..3a0e38a 100644
--- a/boot/bootutil/include/bootutil/bootutil_public.h
+++ b/boot/bootutil/include/bootutil/bootutil_public.h
@@ -99,6 +99,7 @@
 #define BOOT_EBADVERSION 8
 #define BOOT_EFLASH_SEC  9
 
+#define BOOT_HOOK_REGULAR 1
 /*
  * Extract the swap type and image number from image trailers's swap_info
  * filed.
diff --git a/boot/bootutil/src/loader.c b/boot/bootutil/src/loader.c
index e977d65..8816d63 100644
--- a/boot/bootutil/src/loader.c
+++ b/boot/bootutil/src/loader.c
@@ -44,6 +44,7 @@
 #include "bootutil/boot_record.h"
 #include "bootutil/fault_injection_hardening.h"
 #include "bootutil/ramload.h"
+#include "bootutil/boot_hooks.h"
 
 #ifdef MCUBOOT_ENC_IMAGES
 #include "bootutil/enc_key.h"
@@ -102,7 +103,12 @@
     int i;
 
     for (i = 0; i < BOOT_NUM_SLOTS; i++) {
-        rc = boot_read_image_header(state, i, boot_img_hdr(state, i), bs);
+        rc = BOOT_HOOK_CALL(boot_read_image_header_hook, BOOT_HOOK_REGULAR,
+                            BOOT_CURR_IMG(state), i, boot_img_hdr(state, i));
+        if (rc == BOOT_HOOK_REGULAR)
+        {
+            rc = boot_read_image_header(state, i, boot_img_hdr(state, i), bs);
+        }
         if (rc != 0) {
             /* If `require_all` is set, fail on any single fail, otherwise
              * if at least the first slot's header was read successfully,
@@ -759,8 +765,12 @@
         }
     }
 #endif
-
-    FIH_CALL(boot_image_check, fih_rc, state, hdr, fap, bs);
+    BOOT_HOOK_CALL_FIH(boot_image_check_hook, fih_int_encode(BOOT_HOOK_REGULAR),
+                       fih_rc, BOOT_CURR_IMG(state), slot);
+    if (fih_eq(fih_rc, BOOT_HOOK_REGULAR))
+    {
+        FIH_CALL(boot_image_check, fih_rc, state, hdr, fap, bs);
+    }
     if (!boot_is_header_valid(hdr, fap) || fih_not_eq(fih_rc, FIH_SUCCESS)) {
         if ((slot != BOOT_PRIMARY_SLOT) || ARE_SLOTS_EQUIVALENT()) {
             flash_area_erase(fap, 0, flash_area_get_size(fap));
@@ -1107,6 +1117,12 @@
     }
 #endif
 
+    rc = BOOT_HOOK_CALL(boot_copy_region_post_hook, 0, BOOT_CURR_IMG(state),
+                        BOOT_IMG_AREA(state, BOOT_PRIMARY_SLOT), size);
+    if (rc != 0) {
+        return rc;
+    }
+
 #ifdef MCUBOOT_HW_ROLLBACK_PROT
     /* Update the stored security counter with the new image's security counter
      * value. Both slots hold the new image at this point, but the secondary
@@ -1964,7 +1980,13 @@
         case BOOT_SWAP_TYPE_TEST:          /* fallthrough */
         case BOOT_SWAP_TYPE_PERM:          /* fallthrough */
         case BOOT_SWAP_TYPE_REVERT:
-            rc = boot_perform_update(state, &bs);
+            rc = BOOT_HOOK_CALL(boot_perform_update_hook, BOOT_HOOK_REGULAR,
+                                BOOT_CURR_IMG(state), &(BOOT_IMG(state, 1).hdr),
+                                BOOT_IMG_AREA(state, BOOT_SECONDARY_SLOT));
+            if (rc == BOOT_HOOK_REGULAR)
+            {
+                rc = boot_perform_update(state, &bs);
+            }
             assert(rc == 0);
             break;