bootutil: extracted app common library from bootutil_misc

Part of code of boot/bootutil/ is re-implemented in zephyr-rtos
repository.
As some code are defined here and there it becomes problem when
need to include it with outstanding feature in a build.
It is possible to mitigate problem using #fdefry - but this was
rather temporary hack.

This patch introduce new module which is common for MCUBoot build
and application build.
Common code were extracted to bootutil_public.c source file and
bootutil_public.h header

MCUboot also select DISABLE_MCUBOOT_BOOTUTIL_LIB_OWN_LOG Kconfig
option, as it must define log configuration on its own for all its
sourcecode.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
diff --git a/boot/bootutil/CMakeLists.txt b/boot/bootutil/CMakeLists.txt
index 402adf7..b23131e 100644
--- a/boot/bootutil/CMakeLists.txt
+++ b/boot/bootutil/CMakeLists.txt
@@ -18,6 +18,7 @@
     PRIVATE
         src/boot_record.c
         src/bootutil_misc.c
+        src/bootutil_public.c
         src/caps.c
         src/encrypted.c
         src/fault_injection_hardening.c
diff --git a/boot/bootutil/include/bootutil/bootutil.h b/boot/bootutil/include/bootutil/bootutil.h
index eb824a0..b45334a 100644
--- a/boot/bootutil/include/bootutil/bootutil.h
+++ b/boot/bootutil/include/bootutil/bootutil.h
@@ -30,37 +30,12 @@
 
 #include <inttypes.h>
 #include "bootutil/fault_injection_hardening.h"
+#include "bootutil/bootutil_public.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/** Attempt to boot the contents of the primary slot. */
-#define BOOT_SWAP_TYPE_NONE     1
-
-/**
- * Swap to the secondary slot.
- * Absent a confirm command, revert back on next boot.
- */
-#define BOOT_SWAP_TYPE_TEST     2
-
-/**
- * Swap to the secondary slot,
- * and permanently switch to booting its contents.
- */
-#define BOOT_SWAP_TYPE_PERM     3
-
-/** Swap back to alternate slot.  A confirm changes this state to NONE. */
-#define BOOT_SWAP_TYPE_REVERT   4
-
-/** Swap failed because image to be run is not valid */
-#define BOOT_SWAP_TYPE_FAIL     5
-
-/** Swapping encountered an unrecoverable error */
-#define BOOT_SWAP_TYPE_PANIC    0xff
-
-#define BOOT_MAX_ALIGN          8
-
 struct image_header;
 /**
  * A response object provided by the boot loader code; indicates where to jump
@@ -97,12 +72,6 @@
 struct boot_loader_state;
 fih_int context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp);
 
-int boot_swap_type_multi(int image_index);
-int boot_swap_type(void);
-
-int boot_set_pending(int permanent);
-int boot_set_confirmed(void);
-
 #define SPLIT_GO_OK                 (0)
 #define SPLIT_GO_NON_MATCHING       (-1)
 #define SPLIT_GO_ERR                (-2)
diff --git a/boot/bootutil/include/bootutil/bootutil_public.h b/boot/bootutil/include/bootutil/bootutil_public.h
new file mode 100644
index 0000000..60ee828
--- /dev/null
+++ b/boot/bootutil/include/bootutil/bootutil_public.h
@@ -0,0 +1,99 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2017-2019 Linaro LTD
+ * Copyright (c) 2016-2019 JUUL Labs
+ * Copyright (c) 2019-2020 Arm Limited
+ * Copyright (c) 2020 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.
+ */
+
+#ifndef H_BOOTUTIL_PUBLIC
+#define H_BOOTUTIL_PUBLIC
+
+#include <inttypes.h>
+#include <string.h>
+#include <flash_map_backend/flash_map_backend.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Attempt to boot the contents of the primary slot. */
+#define BOOT_SWAP_TYPE_NONE     1
+
+/**
+ * Swap to the secondary slot.
+ * Absent a confirm command, revert back on next boot.
+ */
+#define BOOT_SWAP_TYPE_TEST     2
+
+/**
+ * Swap to the secondary slot,
+ * and permanently switch to booting its contents.
+ */
+#define BOOT_SWAP_TYPE_PERM     3
+
+/** Swap back to alternate slot.  A confirm changes this state to NONE. */
+#define BOOT_SWAP_TYPE_REVERT   4
+
+/** Swap failed because image to be run is not valid */
+#define BOOT_SWAP_TYPE_FAIL     5
+
+/** Swapping encountered an unrecoverable error */
+#define BOOT_SWAP_TYPE_PANIC    0xff
+
+#define BOOT_MAX_ALIGN          8
+
+#define BOOT_MAGIC_GOOD     1
+#define BOOT_MAGIC_BAD      2
+#define BOOT_MAGIC_UNSET    3
+#define BOOT_MAGIC_ANY      4  /* NOTE: control only, not dependent on sector */
+#define BOOT_MAGIC_NOTGOOD  5  /* NOTE: control only, not dependent on sector */
+
+/*
+ * NOTE: leave BOOT_FLAG_SET equal to one, this is written to flash!
+ */
+#define BOOT_FLAG_SET       1
+#define BOOT_FLAG_BAD       2
+#define BOOT_FLAG_UNSET     3
+#define BOOT_FLAG_ANY       4  /* NOTE: control only, not dependent on sector */
+
+#define BOOT_MAGIC_SZ (sizeof boot_img_magic)
+
+int boot_swap_type_multi(int image_index);
+int boot_swap_type(void);
+
+int boot_set_pending(int permanent);
+int boot_set_confirmed(void);
+uint32_t boot_swap_info_off(const struct flash_area *fap);
+
+#define BOOT_MAGIC_ARR_SZ \
+    (sizeof boot_img_magic / sizeof boot_img_magic[0])
+
+extern const uint32_t boot_img_magic[4];
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/boot/bootutil/src/bootutil_misc.c b/boot/bootutil/src/bootutil_misc.c
index 57ceff4..fa5406d 100644
--- a/boot/bootutil/src/bootutil_misc.c
+++ b/boot/bootutil/src/bootutil_misc.c
@@ -46,67 +46,11 @@
 /* Currently only used by imgmgr */
 int boot_current_slot;
 
-const uint32_t boot_img_magic[] = {
-    0xf395c277,
-    0x7fefd260,
-    0x0f505235,
-    0x8079b62c,
-};
+extern const uint32_t boot_img_magic[];
 
 #define BOOT_MAGIC_ARR_SZ \
     (sizeof boot_img_magic / sizeof boot_img_magic[0])
 
-struct boot_swap_table {
-    uint8_t magic_primary_slot;
-    uint8_t magic_secondary_slot;
-    uint8_t image_ok_primary_slot;
-    uint8_t image_ok_secondary_slot;
-    uint8_t copy_done_primary_slot;
-
-    uint8_t swap_type;
-};
-
-/**
- * This set of tables maps image trailer contents to swap operation type.
- * When searching for a match, these tables must be iterated sequentially.
- *
- * NOTE: the table order is very important. The settings in the secondary
- * slot always are priority to the primary slot and should be located
- * earlier in the table.
- *
- * The table lists only states where there is action needs to be taken by
- * the bootloader, as in starting/finishing a swap operation.
- */
-static const struct boot_swap_table boot_swap_tables[] = {
-    {
-        .magic_primary_slot =       BOOT_MAGIC_ANY,
-        .magic_secondary_slot =     BOOT_MAGIC_GOOD,
-        .image_ok_primary_slot =    BOOT_FLAG_ANY,
-        .image_ok_secondary_slot =  BOOT_FLAG_UNSET,
-        .copy_done_primary_slot =   BOOT_FLAG_ANY,
-        .swap_type =                BOOT_SWAP_TYPE_TEST,
-    },
-    {
-        .magic_primary_slot =       BOOT_MAGIC_ANY,
-        .magic_secondary_slot =     BOOT_MAGIC_GOOD,
-        .image_ok_primary_slot =    BOOT_FLAG_ANY,
-        .image_ok_secondary_slot =  BOOT_FLAG_SET,
-        .copy_done_primary_slot =   BOOT_FLAG_ANY,
-        .swap_type =                BOOT_SWAP_TYPE_PERM,
-    },
-    {
-        .magic_primary_slot =       BOOT_MAGIC_GOOD,
-        .magic_secondary_slot =     BOOT_MAGIC_UNSET,
-        .image_ok_primary_slot =    BOOT_FLAG_UNSET,
-        .image_ok_secondary_slot =  BOOT_FLAG_ANY,
-        .copy_done_primary_slot =   BOOT_FLAG_SET,
-        .swap_type =                BOOT_SWAP_TYPE_REVERT,
-    },
-};
-
-#define BOOT_SWAP_TABLES_COUNT \
-    (sizeof boot_swap_tables / sizeof boot_swap_tables[0])
-
 /**
  * @brief Determine if the data at two memory addresses is equal
  *
@@ -150,50 +94,6 @@
 }
 #endif
 
-static int
-boot_magic_decode(const uint32_t *magic)
-{
-    if (memcmp(magic, boot_img_magic, BOOT_MAGIC_SZ) == 0) {
-        return BOOT_MAGIC_GOOD;
-    }
-    return BOOT_MAGIC_BAD;
-}
-
-static int
-boot_flag_decode(uint8_t flag)
-{
-    if (flag != BOOT_FLAG_SET) {
-        return BOOT_FLAG_BAD;
-    }
-    return BOOT_FLAG_SET;
-}
-
-/**
- * Determines if a status source table is satisfied by the specified magic
- * code.
- *
- * @param tbl_val               A magic field from a status source table.
- * @param val                   The magic value in a trailer, encoded as a
- *                                  BOOT_MAGIC_[...].
- *
- * @return                      1 if the two values are compatible;
- *                              0 otherwise.
- */
-int
-boot_magic_compatible_check(uint8_t tbl_val, uint8_t val)
-{
-    switch (tbl_val) {
-    case BOOT_MAGIC_ANY:
-        return 1;
-
-    case BOOT_MAGIC_NOTGOOD:
-        return val != BOOT_MAGIC_GOOD;
-
-    default:
-        return tbl_val == val;
-    }
-}
-
 uint32_t
 boot_status_sz(uint32_t min_write_sz)
 {
@@ -266,12 +166,6 @@
     return boot_image_ok_off(fap) - BOOT_MAX_ALIGN;
 }
 
-uint32_t
-boot_swap_info_off(const struct flash_area *fap)
-{
-    return boot_copy_done_off(fap) - BOOT_MAX_ALIGN;
-}
-
 static inline uint32_t
 boot_swap_size_off(const struct flash_area *fap)
 {
@@ -291,109 +185,6 @@
 }
 #endif
 
-bool bootutil_buffer_is_erased(const struct flash_area *area,
-                               const void *buffer, size_t len)
-{
-    size_t i;
-    uint8_t *u8b;
-    uint8_t erased_val;
-
-    if (buffer == NULL || len == 0) {
-        return false;
-    }
-
-    erased_val = flash_area_erased_val(area);
-    for (i = 0, u8b = (uint8_t *)buffer; i < len; i++) {
-        if (u8b[i] != erased_val) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
-int
-boot_read_swap_state(const struct flash_area *fap,
-                     struct boot_swap_state *state)
-{
-    uint32_t magic[BOOT_MAGIC_ARR_SZ];
-    uint32_t off;
-    uint8_t swap_info;
-    int rc;
-
-    off = boot_magic_off(fap);
-    rc = flash_area_read(fap, off, magic, BOOT_MAGIC_SZ);
-    if (rc < 0) {
-        return BOOT_EFLASH;
-    }
-    if (bootutil_buffer_is_erased(fap, magic, BOOT_MAGIC_SZ)) {
-        state->magic = BOOT_MAGIC_UNSET;
-    } else {
-        state->magic = boot_magic_decode(magic);
-    }
-
-    off = boot_swap_info_off(fap);
-    rc = flash_area_read(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 (bootutil_buffer_is_erased(fap, &swap_info, sizeof swap_info) ||
-            state->swap_type > BOOT_SWAP_TYPE_REVERT) {
-        state->swap_type = BOOT_SWAP_TYPE_NONE;
-        state->image_num = 0;
-    }
-
-    off = boot_copy_done_off(fap);
-    rc = flash_area_read(fap, off, &state->copy_done, sizeof state->copy_done);
-    if (rc < 0) {
-        return BOOT_EFLASH;
-    }
-    if (bootutil_buffer_is_erased(fap, &state->copy_done,
-                sizeof state->copy_done)) {
-        state->copy_done = BOOT_FLAG_UNSET;
-    } else {
-        state->copy_done = boot_flag_decode(state->copy_done);
-    }
-
-    off = boot_image_ok_off(fap);
-    rc = flash_area_read(fap, off, &state->image_ok, sizeof state->image_ok);
-    if (rc < 0) {
-        return BOOT_EFLASH;
-    }
-    if (bootutil_buffer_is_erased(fap, &state->image_ok,
-                sizeof state->image_ok)) {
-        state->image_ok = BOOT_FLAG_UNSET;
-    } else {
-        state->image_ok = boot_flag_decode(state->image_ok);
-    }
-
-    return 0;
-}
-
-/**
- * Reads the image trailer from the scratch area.
- */
-int
-boot_read_swap_state_by_id(int flash_area_id, struct boot_swap_state *state)
-{
-    const struct flash_area *fap;
-    int rc;
-
-    rc = flash_area_open(flash_area_id, &fap);
-    if (rc != 0) {
-        return BOOT_EFLASH;
-    }
-
-    rc = boot_read_swap_state(fap, state);
-    flash_area_close(fap);
-    return rc;
-}
-
 /**
  * This functions tries to locate the status area after an aborted swap,
  * by looking for the magic in the possible locations.
@@ -503,25 +294,6 @@
 }
 #endif
 
-int
-boot_write_magic(const struct flash_area *fap)
-{
-    uint32_t off;
-    int rc;
-
-    off = boot_magic_off(fap);
-
-    BOOT_LOG_DBG("writing magic; fa_id=%d off=0x%lx (0x%lx)",
-                 fap->fa_id, (unsigned long)off,
-                 (unsigned long)(fap->fa_off + off));
-    rc = flash_area_write(fap, off, boot_img_magic, BOOT_MAGIC_SZ);
-    if (rc != 0) {
-        return BOOT_EFLASH;
-    }
-
-    return 0;
-}
-
 /**
  * Write trailer data; status bytes, swap_size, etc
  *
@@ -576,39 +348,6 @@
 }
 
 int
-boot_write_image_ok(const struct flash_area *fap)
-{
-    uint32_t off;
-
-    off = boot_image_ok_off(fap);
-    BOOT_LOG_DBG("writing image_ok; fa_id=%d off=0x%lx (0x%lx)",
-                 fap->fa_id, (unsigned long)off,
-                 (unsigned long)(fap->fa_off + off));
-    return boot_write_trailer_flag(fap, off, BOOT_FLAG_SET);
-}
-
-/**
- * Writes the specified value to the `swap-type` field of an image trailer.
- * This value is persisted so that the boot loader knows what swap operation to
- * resume in case of an unexpected reset.
- */
-int
-boot_write_swap_info(const struct flash_area *fap, uint8_t swap_type,
-                     uint8_t image_num)
-{
-    uint32_t off;
-    uint8_t swap_info;
-
-    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%lx (0x%lx), swap_type=0x%x"
-                 " image_num=0x%x",
-                 fap->fa_id, (unsigned long)off,
-                 (unsigned long)(fap->fa_off + off), swap_type, image_num);
-    return boot_write_trailer(fap, off, (const uint8_t *) &swap_info, 1);
-}
-
-int
 boot_write_swap_size(const struct flash_area *fap, uint32_t swap_size)
 {
     uint32_t off;
@@ -644,196 +383,3 @@
     return 0;
 }
 #endif
-
-int
-boot_swap_type_multi(int image_index)
-{
-    const struct boot_swap_table *table;
-    struct boot_swap_state primary_slot;
-    struct boot_swap_state secondary_slot;
-    int rc;
-    size_t i;
-
-    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_PRIMARY(image_index),
-                                    &primary_slot);
-    if (rc) {
-        return BOOT_SWAP_TYPE_PANIC;
-    }
-
-    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SECONDARY(image_index),
-                                    &secondary_slot);
-    if (rc) {
-        return BOOT_SWAP_TYPE_PANIC;
-    }
-
-    for (i = 0; i < BOOT_SWAP_TABLES_COUNT; i++) {
-        table = boot_swap_tables + i;
-
-        if (boot_magic_compatible_check(table->magic_primary_slot,
-                                        primary_slot.magic) &&
-            boot_magic_compatible_check(table->magic_secondary_slot,
-                                        secondary_slot.magic) &&
-            (table->image_ok_primary_slot == BOOT_FLAG_ANY   ||
-                table->image_ok_primary_slot == primary_slot.image_ok) &&
-            (table->image_ok_secondary_slot == BOOT_FLAG_ANY ||
-                table->image_ok_secondary_slot == secondary_slot.image_ok) &&
-            (table->copy_done_primary_slot == BOOT_FLAG_ANY  ||
-                table->copy_done_primary_slot == primary_slot.copy_done)) {
-            BOOT_LOG_INF("Swap type: %s",
-                         table->swap_type == BOOT_SWAP_TYPE_TEST   ? "test"   :
-                         table->swap_type == BOOT_SWAP_TYPE_PERM   ? "perm"   :
-                         table->swap_type == BOOT_SWAP_TYPE_REVERT ? "revert" :
-                         "BUG; can't happen");
-            if (table->swap_type != BOOT_SWAP_TYPE_TEST &&
-                    table->swap_type != BOOT_SWAP_TYPE_PERM &&
-                    table->swap_type != BOOT_SWAP_TYPE_REVERT) {
-                return BOOT_SWAP_TYPE_PANIC;
-            }
-            return table->swap_type;
-        }
-    }
-
-    BOOT_LOG_INF("Swap type: none");
-    return BOOT_SWAP_TYPE_NONE;
-}
-
-/*
- * This function is not used by the bootloader itself, but its required API
- * by external tooling like mcumgr.
- */
-int
-boot_swap_type(void)
-{
-    return boot_swap_type_multi(0);
-}
-
-/**
- * Marks the image in the secondary slot as pending.  On the next reboot,
- * the system will perform a one-time boot of the the secondary slot image.
- *
- * @param permanent         Whether the image should be used permanently or
- *                              only tested once:
- *                                  0=run image once, then confirm or revert.
- *                                  1=run image forever.
- *
- * @return                  0 on success; nonzero on failure.
- */
-int
-boot_set_pending(int permanent)
-{
-    const struct flash_area *fap;
-    struct boot_swap_state state_secondary_slot;
-    uint8_t swap_type;
-    int rc;
-
-    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SECONDARY(0),
-                                    &state_secondary_slot);
-    if (rc != 0) {
-        return rc;
-    }
-
-    switch (state_secondary_slot.magic) {
-    case BOOT_MAGIC_GOOD:
-        /* Swap already scheduled. */
-        return 0;
-
-    case BOOT_MAGIC_UNSET:
-        rc = flash_area_open(FLASH_AREA_IMAGE_SECONDARY(0), &fap);
-        if (rc != 0) {
-            rc = BOOT_EFLASH;
-        } else {
-            rc = boot_write_magic(fap);
-        }
-
-        if (rc == 0 && permanent) {
-            rc = boot_write_image_ok(fap);
-        }
-
-        if (rc == 0) {
-            if (permanent) {
-                swap_type = BOOT_SWAP_TYPE_PERM;
-            } else {
-                swap_type = BOOT_SWAP_TYPE_TEST;
-            }
-            rc = boot_write_swap_info(fap, swap_type, 0);
-        }
-
-        flash_area_close(fap);
-        return rc;
-
-    case BOOT_MAGIC_BAD:
-        /* The image slot is corrupt.  There is no way to recover, so erase the
-         * slot to allow future upgrades.
-         */
-        rc = flash_area_open(FLASH_AREA_IMAGE_SECONDARY(0), &fap);
-        if (rc != 0) {
-            return BOOT_EFLASH;
-        }
-
-        flash_area_erase(fap, 0, fap->fa_size);
-        flash_area_close(fap);
-        return BOOT_EBADIMAGE;
-
-    default:
-        assert(0);
-        return BOOT_EBADIMAGE;
-    }
-}
-
-/**
- * Marks the image in the primary slot as confirmed.  The system will continue
- * booting into the image in the primary slot until told to boot from a
- * different slot.
- *
- * @return                  0 on success; nonzero on failure.
- */
-int
-boot_set_confirmed(void)
-{
-    const struct flash_area *fap;
-    struct boot_swap_state state_primary_slot;
-    int rc;
-
-    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_PRIMARY(0),
-                                    &state_primary_slot);
-    if (rc != 0) {
-        return rc;
-    }
-
-    switch (state_primary_slot.magic) {
-    case BOOT_MAGIC_GOOD:
-        /* Confirm needed; proceed. */
-        break;
-
-    case BOOT_MAGIC_UNSET:
-        /* Already confirmed. */
-        return 0;
-
-    case BOOT_MAGIC_BAD:
-        /* Unexpected state. */
-        return BOOT_EBADVECT;
-    }
-
-    rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(0), &fap);
-    if (rc) {
-        rc = BOOT_EFLASH;
-        goto done;
-    }
-
-    if (state_primary_slot.copy_done == BOOT_FLAG_UNSET) {
-        /* Swap never completed.  This is unexpected. */
-        rc = BOOT_EBADVECT;
-        goto done;
-    }
-
-    if (state_primary_slot.image_ok != BOOT_FLAG_UNSET) {
-        /* Already confirmed. */
-        goto done;
-    }
-
-    rc = boot_write_image_ok(fap);
-
-done:
-    flash_area_close(fap);
-    return rc;
-}
diff --git a/boot/bootutil/src/bootutil_priv.h b/boot/bootutil/src/bootutil_priv.h
index 3f40861..2d9eb76 100644
--- a/boot/bootutil/src/bootutil_priv.h
+++ b/boot/bootutil/src/bootutil_priv.h
@@ -106,20 +106,6 @@
     int source;           /* Which slot contains swap status metadata */
 };
 
-#define BOOT_MAGIC_GOOD     1
-#define BOOT_MAGIC_BAD      2
-#define BOOT_MAGIC_UNSET    3
-#define BOOT_MAGIC_ANY      4  /* NOTE: control only, not dependent on sector */
-#define BOOT_MAGIC_NOTGOOD  5  /* NOTE: control only, not dependent on sector */
-
-/*
- * NOTE: leave BOOT_FLAG_SET equal to one, this is written to flash!
- */
-#define BOOT_FLAG_SET       1
-#define BOOT_FLAG_BAD       2
-#define BOOT_FLAG_UNSET     3
-#define BOOT_FLAG_ANY       4  /* NOTE: control only, not dependent on sector */
-
 #define BOOT_STATUS_IDX_0   1
 
 #define BOOT_STATUS_STATE_0 1
@@ -243,8 +229,6 @@
 #define BOOT_STATUS_SOURCE_SCRATCH      1
 #define BOOT_STATUS_SOURCE_PRIMARY_SLOT 2
 
-#define BOOT_MAGIC_SZ (sizeof boot_img_magic)
-
 /**
  * Compatibility shim for flash sector type.
  *
@@ -295,7 +279,6 @@
 uint32_t boot_trailer_sz(uint32_t min_write_sz);
 int boot_status_entries(int image_index, const struct flash_area *fap);
 uint32_t boot_status_off(const struct flash_area *fap);
-uint32_t boot_swap_info_off(const struct flash_area *fap);
 int boot_read_swap_state(const struct flash_area *fap,
                          struct boot_swap_state *state);
 int boot_read_swap_state_by_id(int flash_area_id,
diff --git a/boot/bootutil/src/bootutil_public.c b/boot/bootutil/src/bootutil_public.c
new file mode 100644
index 0000000..f40e1be
--- /dev/null
+++ b/boot/bootutil/src/bootutil_public.c
@@ -0,0 +1,585 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2017-2019 Linaro LTD
+ * Copyright (c) 2016-2019 JUUL Labs
+ * Copyright (c) 2019-2020 Arm Limited
+ * Copyright (c) 2020 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.
+ */
+
+#include <string.h>
+#include <inttypes.h>
+#include <stddef.h>
+
+#include "sysflash/sysflash.h"
+#include "flash_map_backend/flash_map_backend.h"
+
+#include "bootutil/image.h"
+#include "bootutil/bootutil_public.h"
+#include "bootutil_priv.h"
+#include "bootutil/bootutil_log.h"
+#ifdef MCUBOOT_ENC_IMAGES
+#include "bootutil/enc_key.h"
+#endif
+
+#ifdef CONFIG_MCUBOOT
+MCUBOOT_LOG_MODULE_DECLARE(mcuboot);
+#else
+MCUBOOT_LOG_MODULE_REGISTER(mcuboot_util);
+#endif
+
+const uint32_t boot_img_magic[] = {
+    0xf395c277,
+    0x7fefd260,
+    0x0f505235,
+    0x8079b62c,
+};
+
+#define BOOT_MAGIC_ARR_SZ \
+    (sizeof boot_img_magic / sizeof boot_img_magic[0])
+
+struct boot_swap_table {
+    uint8_t magic_primary_slot;
+    uint8_t magic_secondary_slot;
+    uint8_t image_ok_primary_slot;
+    uint8_t image_ok_secondary_slot;
+    uint8_t copy_done_primary_slot;
+
+    uint8_t swap_type;
+};
+
+/**
+ * This set of tables maps image trailer contents to swap operation type.
+ * When searching for a match, these tables must be iterated sequentially.
+ *
+ * NOTE: the table order is very important. The settings in the secondary
+ * slot always are priority to the primary slot and should be located
+ * earlier in the table.
+ *
+ * The table lists only states where there is action needs to be taken by
+ * the bootloader, as in starting/finishing a swap operation.
+ */
+static const struct boot_swap_table boot_swap_tables[] = {
+    {
+        .magic_primary_slot =       BOOT_MAGIC_ANY,
+        .magic_secondary_slot =     BOOT_MAGIC_GOOD,
+        .image_ok_primary_slot =    BOOT_FLAG_ANY,
+        .image_ok_secondary_slot =  BOOT_FLAG_UNSET,
+        .copy_done_primary_slot =   BOOT_FLAG_ANY,
+        .swap_type =                BOOT_SWAP_TYPE_TEST,
+    },
+    {
+        .magic_primary_slot =       BOOT_MAGIC_ANY,
+        .magic_secondary_slot =     BOOT_MAGIC_GOOD,
+        .image_ok_primary_slot =    BOOT_FLAG_ANY,
+        .image_ok_secondary_slot =  BOOT_FLAG_SET,
+        .copy_done_primary_slot =   BOOT_FLAG_ANY,
+        .swap_type =                BOOT_SWAP_TYPE_PERM,
+    },
+    {
+        .magic_primary_slot =       BOOT_MAGIC_GOOD,
+        .magic_secondary_slot =     BOOT_MAGIC_UNSET,
+        .image_ok_primary_slot =    BOOT_FLAG_UNSET,
+        .image_ok_secondary_slot =  BOOT_FLAG_ANY,
+        .copy_done_primary_slot =   BOOT_FLAG_SET,
+        .swap_type =                BOOT_SWAP_TYPE_REVERT,
+    },
+};
+
+#define BOOT_SWAP_TABLES_COUNT \
+    (sizeof boot_swap_tables / sizeof boot_swap_tables[0])
+
+static int
+boot_magic_decode(const uint32_t *magic)
+{
+    if (memcmp(magic, boot_img_magic, BOOT_MAGIC_SZ) == 0) {
+        return BOOT_MAGIC_GOOD;
+    }
+    return BOOT_MAGIC_BAD;
+}
+
+static int
+boot_flag_decode(uint8_t flag)
+{
+    if (flag != BOOT_FLAG_SET) {
+        return BOOT_FLAG_BAD;
+    }
+    return BOOT_FLAG_SET;
+}
+
+static inline uint32_t
+boot_magic_off(const struct flash_area *fap)
+{
+    return fap->fa_size - BOOT_MAGIC_SZ;
+}
+
+static inline uint32_t
+boot_image_ok_off(const struct flash_area *fap)
+{
+    return boot_magic_off(fap) - BOOT_MAX_ALIGN;
+}
+
+static inline uint32_t
+boot_copy_done_off(const struct flash_area *fap)
+{
+    return boot_image_ok_off(fap) - BOOT_MAX_ALIGN;
+}
+
+static inline uint32_t
+boot_swap_size_off(const struct flash_area *fap)
+{
+    return boot_swap_info_off(fap) - BOOT_MAX_ALIGN;
+}
+
+uint32_t
+boot_swap_info_off(const struct flash_area *fap)
+{
+    return boot_copy_done_off(fap) - BOOT_MAX_ALIGN;
+}
+
+/**
+ * Determines if a status source table is satisfied by the specified magic
+ * code.
+ *
+ * @param tbl_val               A magic field from a status source table.
+ * @param val                   The magic value in a trailer, encoded as a
+ *                                  BOOT_MAGIC_[...].
+ *
+ * @return                      1 if the two values are compatible;
+ *                              0 otherwise.
+ */
+int
+boot_magic_compatible_check(uint8_t tbl_val, uint8_t val)
+{
+    switch (tbl_val) {
+    case BOOT_MAGIC_ANY:
+        return 1;
+
+    case BOOT_MAGIC_NOTGOOD:
+        return val != BOOT_MAGIC_GOOD;
+
+    default:
+        return tbl_val == val;
+    }
+}
+
+#ifdef MCUBOOT_ENC_IMAGES
+static inline uint32_t
+boot_enc_key_off(const struct flash_area *fap, uint8_t slot)
+{
+#if MCUBOOT_SWAP_SAVE_ENCTLV
+    return boot_swap_size_off(fap) - ((slot + 1) *
+            ((((BOOT_ENC_TLV_SIZE - 1) / BOOT_MAX_ALIGN) + 1) * BOOT_MAX_ALIGN));
+#else
+    return boot_swap_size_off(fap) - ((slot + 1) * BOOT_ENC_KEY_SIZE);
+#endif
+}
+#endif
+
+bool bootutil_buffer_is_erased(const struct flash_area *area,
+                               const void *buffer, size_t len)
+{
+    size_t i;
+    uint8_t *u8b;
+    uint8_t erased_val;
+
+    if (buffer == NULL || len == 0) {
+        return false;
+    }
+
+    erased_val = flash_area_erased_val(area);
+    for (i = 0, u8b = (uint8_t *)buffer; i < len; i++) {
+        if (u8b[i] != erased_val) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+int
+boot_read_swap_state(const struct flash_area *fap,
+                     struct boot_swap_state *state)
+{
+    uint32_t magic[BOOT_MAGIC_ARR_SZ];
+    uint32_t off;
+    uint8_t swap_info;
+    int rc;
+
+    off = boot_magic_off(fap);
+    rc = flash_area_read(fap, off, magic, BOOT_MAGIC_SZ);
+    if (rc < 0) {
+        return BOOT_EFLASH;
+    }
+    if (bootutil_buffer_is_erased(fap, magic, BOOT_MAGIC_SZ)) {
+        state->magic = BOOT_MAGIC_UNSET;
+    } else {
+        state->magic = boot_magic_decode(magic);
+    }
+
+    off = boot_swap_info_off(fap);
+    rc = flash_area_read(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 (bootutil_buffer_is_erased(fap, &swap_info, sizeof swap_info) ||
+            state->swap_type > BOOT_SWAP_TYPE_REVERT) {
+        state->swap_type = BOOT_SWAP_TYPE_NONE;
+        state->image_num = 0;
+    }
+
+    off = boot_copy_done_off(fap);
+    rc = flash_area_read(fap, off, &state->copy_done, sizeof state->copy_done);
+    if (rc < 0) {
+        return BOOT_EFLASH;
+    }
+    if (bootutil_buffer_is_erased(fap, &state->copy_done,
+                sizeof state->copy_done)) {
+        state->copy_done = BOOT_FLAG_UNSET;
+    } else {
+        state->copy_done = boot_flag_decode(state->copy_done);
+    }
+
+    off = boot_image_ok_off(fap);
+    rc = flash_area_read(fap, off, &state->image_ok, sizeof state->image_ok);
+    if (rc < 0) {
+        return BOOT_EFLASH;
+    }
+    if (bootutil_buffer_is_erased(fap, &state->image_ok,
+                sizeof state->image_ok)) {
+        state->image_ok = BOOT_FLAG_UNSET;
+    } else {
+        state->image_ok = boot_flag_decode(state->image_ok);
+    }
+
+    return 0;
+}
+
+/**
+ * Reads the image trailer from the scratch area.
+ */
+int
+boot_read_swap_state_by_id(int flash_area_id, struct boot_swap_state *state)
+{
+    const struct flash_area *fap;
+    int rc;
+
+    rc = flash_area_open(flash_area_id, &fap);
+    if (rc != 0) {
+        return BOOT_EFLASH;
+    }
+
+    rc = boot_read_swap_state(fap, state);
+    flash_area_close(fap);
+    return rc;
+}
+
+int
+boot_write_magic(const struct flash_area *fap)
+{
+    uint32_t off;
+    int rc;
+
+    off = boot_magic_off(fap);
+
+    BOOT_LOG_DBG("writing magic; fa_id=%d off=0x%lx (0x%lx)",
+                 fap->fa_id, (unsigned long)off,
+                 (unsigned long)(fap->fa_off + off));
+    rc = flash_area_write(fap, off, boot_img_magic, BOOT_MAGIC_SZ);
+    if (rc != 0) {
+        return BOOT_EFLASH;
+    }
+
+    return 0;
+}
+
+/**
+ * Write trailer data; status bytes, swap_size, etc
+ *
+ * @returns 0 on success, != 0 on error.
+ */
+static int
+boot_write_trailer(const struct flash_area *fap, uint32_t off,
+        const uint8_t *inbuf, uint8_t inlen)
+{
+    uint8_t buf[BOOT_MAX_ALIGN];
+    uint8_t align;
+    uint8_t erased_val;
+    int rc;
+
+    align = flash_area_align(fap);
+    if (inlen > BOOT_MAX_ALIGN || align > BOOT_MAX_ALIGN) {
+        return -1;
+    }
+    erased_val = flash_area_erased_val(fap);
+    if (align < inlen) {
+        align = inlen;
+    }
+    memcpy(buf, inbuf, inlen);
+    memset(&buf[inlen], erased_val, align - inlen);
+
+    rc = flash_area_write(fap, off, buf, align);
+    if (rc != 0) {
+        return BOOT_EFLASH;
+    }
+
+    return 0;
+}
+
+static int
+boot_write_trailer_flag(const struct flash_area *fap, uint32_t off,
+        uint8_t flag_val)
+{
+    const uint8_t buf[1] = { flag_val };
+    return boot_write_trailer(fap, off, buf, 1);
+}
+
+int
+boot_write_image_ok(const struct flash_area *fap)
+{
+    uint32_t off;
+
+    off = boot_image_ok_off(fap);
+    BOOT_LOG_DBG("writing image_ok; fa_id=%d off=0x%lx (0x%lx)",
+                 fap->fa_id, (unsigned long)off,
+                 (unsigned long)(fap->fa_off + off));
+    return boot_write_trailer_flag(fap, off, BOOT_FLAG_SET);
+}
+
+/**
+ * Writes the specified value to the `swap-type` field of an image trailer.
+ * This value is persisted so that the boot loader knows what swap operation to
+ * resume in case of an unexpected reset.
+ */
+int
+boot_write_swap_info(const struct flash_area *fap, uint8_t swap_type,
+                     uint8_t image_num)
+{
+    uint32_t off;
+    uint8_t swap_info;
+
+    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%lx (0x%lx), swap_type=0x%x"
+                 " image_num=0x%x",
+                 fap->fa_id, (unsigned long)off,
+                 (unsigned long)(fap->fa_off + off), swap_type, image_num);
+    return boot_write_trailer(fap, off, (const uint8_t *) &swap_info, 1);
+}
+
+int
+boot_swap_type_multi(int image_index)
+{
+    const struct boot_swap_table *table;
+    struct boot_swap_state primary_slot;
+    struct boot_swap_state secondary_slot;
+    int rc;
+    size_t i;
+
+    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_PRIMARY(image_index),
+                                    &primary_slot);
+    if (rc) {
+        return BOOT_SWAP_TYPE_PANIC;
+    }
+
+    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SECONDARY(image_index),
+                                    &secondary_slot);
+    if (rc) {
+        return BOOT_SWAP_TYPE_PANIC;
+    }
+
+    for (i = 0; i < BOOT_SWAP_TABLES_COUNT; i++) {
+        table = boot_swap_tables + i;
+
+        if (boot_magic_compatible_check(table->magic_primary_slot,
+                                        primary_slot.magic) &&
+            boot_magic_compatible_check(table->magic_secondary_slot,
+                                        secondary_slot.magic) &&
+            (table->image_ok_primary_slot == BOOT_FLAG_ANY   ||
+                table->image_ok_primary_slot == primary_slot.image_ok) &&
+            (table->image_ok_secondary_slot == BOOT_FLAG_ANY ||
+                table->image_ok_secondary_slot == secondary_slot.image_ok) &&
+            (table->copy_done_primary_slot == BOOT_FLAG_ANY  ||
+                table->copy_done_primary_slot == primary_slot.copy_done)) {
+            BOOT_LOG_INF("Swap type: %s",
+                         table->swap_type == BOOT_SWAP_TYPE_TEST   ? "test"   :
+                         table->swap_type == BOOT_SWAP_TYPE_PERM   ? "perm"   :
+                         table->swap_type == BOOT_SWAP_TYPE_REVERT ? "revert" :
+                         "BUG; can't happen");
+            if (table->swap_type != BOOT_SWAP_TYPE_TEST &&
+                    table->swap_type != BOOT_SWAP_TYPE_PERM &&
+                    table->swap_type != BOOT_SWAP_TYPE_REVERT) {
+                return BOOT_SWAP_TYPE_PANIC;
+            }
+            return table->swap_type;
+        }
+    }
+
+    BOOT_LOG_INF("Swap type: none");
+    return BOOT_SWAP_TYPE_NONE;
+}
+
+/*
+ * This function is not used by the bootloader itself, but its required API
+ * by external tooling like mcumgr.
+ */
+int
+boot_swap_type(void)
+{
+    return boot_swap_type_multi(0);
+}
+
+/**
+ * Marks the image in the secondary slot as pending.  On the next reboot,
+ * the system will perform a one-time boot of the the secondary slot image.
+ *
+ * @param permanent         Whether the image should be used permanently or
+ *                              only tested once:
+ *                                  0=run image once, then confirm or revert.
+ *                                  1=run image forever.
+ *
+ * @return                  0 on success; nonzero on failure.
+ */
+int
+boot_set_pending(int permanent)
+{
+    const struct flash_area *fap;
+    struct boot_swap_state state_secondary_slot;
+    uint8_t swap_type;
+    int rc;
+
+    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_SECONDARY(0),
+                                    &state_secondary_slot);
+    if (rc != 0) {
+        return rc;
+    }
+
+    switch (state_secondary_slot.magic) {
+    case BOOT_MAGIC_GOOD:
+        /* Swap already scheduled. */
+        return 0;
+
+    case BOOT_MAGIC_UNSET:
+        rc = flash_area_open(FLASH_AREA_IMAGE_SECONDARY(0), &fap);
+        if (rc != 0) {
+            rc = BOOT_EFLASH;
+        } else {
+            rc = boot_write_magic(fap);
+        }
+
+        if (rc == 0 && permanent) {
+            rc = boot_write_image_ok(fap);
+        }
+
+        if (rc == 0) {
+            if (permanent) {
+                swap_type = BOOT_SWAP_TYPE_PERM;
+            } else {
+                swap_type = BOOT_SWAP_TYPE_TEST;
+            }
+            rc = boot_write_swap_info(fap, swap_type, 0);
+        }
+
+        flash_area_close(fap);
+        return rc;
+
+    case BOOT_MAGIC_BAD:
+        /* The image slot is corrupt.  There is no way to recover, so erase the
+         * slot to allow future upgrades.
+         */
+        rc = flash_area_open(FLASH_AREA_IMAGE_SECONDARY(0), &fap);
+        if (rc != 0) {
+            return BOOT_EFLASH;
+        }
+
+        flash_area_erase(fap, 0, fap->fa_size);
+        flash_area_close(fap);
+        return BOOT_EBADIMAGE;
+
+    default:
+        assert(0);
+        return BOOT_EBADIMAGE;
+    }
+}
+
+/**
+ * Marks the image in the primary slot as confirmed.  The system will continue
+ * booting into the image in the primary slot until told to boot from a
+ * different slot.
+ *
+ * @return                  0 on success; nonzero on failure.
+ */
+int
+boot_set_confirmed(void)
+{
+    const struct flash_area *fap;
+    struct boot_swap_state state_primary_slot;
+    int rc;
+
+    rc = boot_read_swap_state_by_id(FLASH_AREA_IMAGE_PRIMARY(0),
+                                    &state_primary_slot);
+    if (rc != 0) {
+        return rc;
+    }
+
+    switch (state_primary_slot.magic) {
+    case BOOT_MAGIC_GOOD:
+        /* Confirm needed; proceed. */
+        break;
+
+    case BOOT_MAGIC_UNSET:
+        /* Already confirmed. */
+        return 0;
+
+    case BOOT_MAGIC_BAD:
+        /* Unexpected state. */
+        return BOOT_EBADVECT;
+    }
+
+    rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(0), &fap);
+    if (rc) {
+        rc = BOOT_EFLASH;
+        goto done;
+    }
+
+    if (state_primary_slot.copy_done == BOOT_FLAG_UNSET) {
+        /* Swap never completed.  This is unexpected. */
+        rc = BOOT_EBADVECT;
+        goto done;
+    }
+
+    if (state_primary_slot.image_ok != BOOT_FLAG_UNSET) {
+        /* Already confirmed. */
+        goto done;
+    }
+
+    rc = boot_write_image_ok(fap);
+
+done:
+    flash_area_close(fap);
+    return rc;
+}
diff --git a/boot/bootutil/zephyr/CMakeLists.txt b/boot/bootutil/zephyr/CMakeLists.txt
new file mode 100644
index 0000000..82985ce
--- /dev/null
+++ b/boot/bootutil/zephyr/CMakeLists.txt
@@ -0,0 +1,21 @@
+# Copyright (c) 2020 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+
+if(CONFIG_MCUBOOT_BOOTUTIL_LIB)
+
+zephyr_interface_library_named(MCUBOOT_BOOTUTIL)
+
+target_include_directories(MCUBOOT_BOOTUTIL INTERFACE
+  ../
+  ../include
+  ../../zephyr/include
+)
+
+zephyr_library()
+zephyr_library_sources(
+  ../src/bootutil_public.c
+    )
+zephyr_library_link_libraries(MCUBOOT_BOOTUTIL)
+target_link_libraries(MCUBOOT_BOOTUTIL INTERFACE zephyr_interface)
+endif()
diff --git a/boot/zephyr/CMakeLists.txt b/boot/zephyr/CMakeLists.txt
index 1b6024d..49b0fa0 100644
--- a/boot/zephyr/CMakeLists.txt
+++ b/boot/zephyr/CMakeLists.txt
@@ -113,6 +113,9 @@
   ${BOOT_DIR}/bootutil/src/fault_injection_hardening.c
   )
 
+# library which might be common source code for MCUBoot and an application
+zephyr_link_libraries(MCUBOOT_BOOTUTIL)
+
 if(CONFIG_BOOT_FIH_PROFILE_HIGH)
 zephyr_library_sources(
   ${BOOT_DIR}/bootutil/src/fault_injection_hardening_delay_rng_mbedtls.c
diff --git a/boot/zephyr/Kconfig b/boot/zephyr/Kconfig
index 0d0bed3..ef3e834 100644
--- a/boot/zephyr/Kconfig
+++ b/boot/zephyr/Kconfig
@@ -14,6 +14,7 @@
 	bool
 	select MPU_ALLOW_FLASH_WRITE if ARM_MPU
 	select USE_DT_CODE_PARTITION if HAS_FLASH_LOAD_OFFSET
+	select MCUBOOT_BOOTUTIL_LIB
 
 config BOOT_USE_MBEDTLS
 	bool
@@ -573,4 +574,9 @@
 config USB_DEVICE_PRODUCT
 	default "MCUBOOT"
 
+# use MCUboot's own log configuration
+config MCUBOOT_BOOTUTIL_LIB_OWN_LOG
+	bool
+	default n
+
 source "Kconfig.zephyr"
diff --git a/boot/zephyr/include/mcuboot_config/mcuboot_config.h b/boot/zephyr/include/mcuboot_config/mcuboot_config.h
index 4f852be..8f2b157 100644
--- a/boot/zephyr/include/mcuboot_config/mcuboot_config.h
+++ b/boot/zephyr/include/mcuboot_config/mcuboot_config.h
@@ -154,8 +154,14 @@
  */
 #define MCUBOOT_USE_FLASH_AREA_GET_SECTORS
 
+#ifdef CONFIG_BOOT_MAX_IMG_SECTORS
+
 #define MCUBOOT_MAX_IMG_SECTORS       CONFIG_BOOT_MAX_IMG_SECTORS
 
+#else
+#define MCUBOOT_MAX_IMG_SECTORS       128
+#endif
+
 #endif /* !__BOOTSIM__ */
 
 #if CONFIG_BOOT_WATCHDOG_FEED
diff --git a/boot/zephyr/include/mcuboot_config/mcuboot_logging.h b/boot/zephyr/include/mcuboot_config/mcuboot_logging.h
index fa43a80..6f24868 100644
--- a/boot/zephyr/include/mcuboot_config/mcuboot_logging.h
+++ b/boot/zephyr/include/mcuboot_config/mcuboot_logging.h
@@ -13,9 +13,13 @@
  * When building for targets running Zephyr, delegate to its native
  * logging subsystem.
  */
-
+#ifdef CONFIG_MCUBOOT
 #define MCUBOOT_LOG_MODULE_DECLARE(domain)	LOG_MODULE_DECLARE(domain, CONFIG_MCUBOOT_LOG_LEVEL)
 #define MCUBOOT_LOG_MODULE_REGISTER(domain)	LOG_MODULE_REGISTER(domain, CONFIG_MCUBOOT_LOG_LEVEL)
+#else
+#define MCUBOOT_LOG_MODULE_DECLARE(domain)	LOG_MODULE_DECLARE(domain, CONFIG_MCUBOOT_UTIL_LOG_LEVEL)
+#define MCUBOOT_LOG_MODULE_REGISTER(domain)	LOG_MODULE_REGISTER(domain, CONFIG_MCUBOOT_UTIL_LOG_LEVEL)
+#endif
 
 #define MCUBOOT_LOG_ERR(...) LOG_ERR(__VA_ARGS__)
 #define MCUBOOT_LOG_WRN(...) LOG_WRN(__VA_ARGS__)