Infineon: Switch to 1.9.0 code base, add xmc7000 family support, refactor memory layer
diff --git a/boot/bootutil/src/loader.c b/boot/bootutil/src/loader.c
index 7794b5a..bb623e5 100644
--- a/boot/bootutil/src/loader.c
+++ b/boot/bootutil/src/loader.c
@@ -36,6 +36,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include "bootutil/bootutil.h"
+#include "bootutil/bootutil_public.h"
 #include "bootutil/image.h"
 #include "bootutil_priv.h"
 #include "swap_priv.h"
@@ -50,7 +51,7 @@
 #include "bootutil/enc_key.h"
 #endif
 
-#if !defined(MCUBOOT_DIRECT_XIP) && !defined(MCUBOOT_RAM_LOAD)
+#if (!defined(MCUBOOT_DIRECT_XIP) && !defined(MCUBOOT_RAM_LOAD)) || defined(MCUBOOT_MULTI_MEMORY_LOAD)
 #include <os/os_malloc.h>
 #endif
 
@@ -63,25 +64,9 @@
 #if (BOOT_IMAGE_NUMBER > 1)
 #define IMAGES_ITER(x) for ((x) = 0; (x) < BOOT_IMAGE_NUMBER; ++(x))
 #else
-#define IMAGES_ITER(x)
+#define IMAGES_ITER(x) for (int iter = 0; iter < 1; ++iter)
 #endif
 
-#if defined(MCUBOOT_DIRECT_XIP) || defined(MCUBOOT_RAM_LOAD)
-struct slot_usage_t {
-    /* Index of the slot chosen to be loaded */
-    uint32_t active_slot;
-    bool slot_available[BOOT_NUM_SLOTS];
-#if defined(MCUBOOT_RAM_LOAD)
-    /* Image destination and size for the active slot */
-    uint32_t img_dst;
-    uint32_t img_sz;
-#elif defined(MCUBOOT_DIRECT_XIP_REVERT)
-    /* Swap status for the active slot */
-    struct boot_swap_state swap_state;
-#endif
-};
-#endif /* MCUBOOT_DIRECT_XIP || MCUBOOT_RAM_LOAD */
-
 /*
  * This macro allows some control on the allocation of local variables.
  * When running natively on a target, we don't want to allocated huge
@@ -95,6 +80,14 @@
 #define TARGET_STATIC
 #endif
 
+#if BOOT_MAX_ALIGN > 1024
+#define BUF_SZ BOOT_MAX_ALIGN
+#else
+#define BUF_SZ 1024U
+#endif
+
+static fih_int FIH_SWAP_TYPE_NONE = FIH_INT_INIT(0x3A5C742E);
+
 static int
 boot_read_image_headers(struct boot_loader_state *state, bool require_all,
         struct boot_status *bs)
@@ -175,26 +168,36 @@
  * Fills rsp to indicate how booting should occur.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
- *                      Only used in MCUBOOT_DIRECT_XIP and MCUBOOT_RAM_LOAD
  * @param  rsp          boot_rsp struct to fill.
  */
 static void
-fill_rsp(struct boot_loader_state *state, void *slot_usage,
-         struct boot_rsp *rsp)
+fill_rsp(struct boot_loader_state *state, struct boot_rsp *rsp)
 {
-    uint32_t active_slot;
+    uint32_t active_slot = BOOT_PRIMARY_SLOT;
 
 #if (BOOT_IMAGE_NUMBER > 1)
-    /* Always boot from Image 0. */
+    /* Always boot from the first enabled image. */
     BOOT_CURR_IMG(state) = 0;
+    IMAGES_ITER(BOOT_CURR_IMG(state)) {
+        if (!state->img_mask[BOOT_CURR_IMG(state)]) {
+            break;
+        }
+    }
+    /* At least one image must be active, otherwise skip the execution */
+    if(BOOT_CURR_IMG(state) >= BOOT_IMAGE_NUMBER)
+    {
+        return;
+    }
 #endif
 
+#if defined(MCUBOOT_MULTI_MEMORY_LOAD)
+    if ((state->slot_usage[BOOT_CURR_IMG(state)].active_slot != BOOT_PRIMARY_SLOT) &&
+        (state->slot_usage[BOOT_CURR_IMG(state)].active_slot != NO_ACTIVE_SLOT))
+#endif
 #if defined(MCUBOOT_DIRECT_XIP) || defined(MCUBOOT_RAM_LOAD)
-    active_slot = ((struct slot_usage_t *)slot_usage)[BOOT_CURR_IMG(state)].active_slot;
-#else
-    (void) (slot_usage);
-    active_slot = BOOT_PRIMARY_SLOT;
+    {
+        active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
+    }
 #endif
 
     rsp->br_flash_dev_id = flash_area_get_device_id(BOOT_IMG_AREA(state, active_slot));
@@ -213,6 +216,11 @@
     uint32_t slot;
 
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
 #if MCUBOOT_SWAP_USING_SCRATCH
         flash_area_close(BOOT_SCRATCH_AREA(state));
 #endif
@@ -227,7 +235,7 @@
  * Compute the total size of the given image.  Includes the size of
  * the TLVs.
  */
-#if !defined(MCUBOOT_OVERWRITE_ONLY) || defined(MCUBOOT_OVERWRITE_ONLY_FAST)
+#if !defined(MCUBOOT_OVERWRITE_ONLY) || defined(MCUBOOT_OVERWRITE_ONLY_FAST) || defined(MCUBOOT_RAM_LOAD)
 static int
 boot_read_image_size(struct boot_loader_state *state, int slot, uint32_t *size)
 {
@@ -271,6 +279,10 @@
         rc = BOOT_EBADIMAGE;
         goto done;
     }
+    else 
+    {
+        /* acc. to MISRA R.15.7 */
+    }
 
     if (info.it_magic != IMAGE_TLV_INFO_MAGIC) {
         rc = BOOT_EBADIMAGE;
@@ -284,9 +296,8 @@
     flash_area_close(fap);
     return rc;
 }
-#endif /* !MCUBOOT_OVERWRITE_ONLY */
 
-#if !defined(MCUBOOT_RAM_LOAD)
+#endif
 
 static uint32_t
 boot_write_sz(struct boot_loader_state *state)
@@ -407,8 +418,8 @@
 {
 #ifdef MCUBOOT_ENC_IMAGES
     (void)memset(&bs->enckey, BOOT_UNINITIALIZED_KEY_FILL,
-                 BOOT_NUM_SLOTS * BOOT_ENC_KEY_SIZE);
-#if MCUBOOT_SWAP_SAVE_ENCTLV
+                 BOOT_NUM_SLOTS * BOOT_ENC_KEY_ALIGN_SIZE);
+#ifdef MCUBOOT_SWAP_SAVE_ENCTLV
     (void)memset(&bs->enctlv, BOOT_UNINITIALIZED_TLV_FILL,
                  BOOT_NUM_SLOTS * BOOT_ENC_TLV_ALIGN_SIZE);
 #endif
@@ -447,9 +458,9 @@
     const struct flash_area *fap = NULL;
     uint32_t off;
     int area_id;
-    int rc;
+    int rc = 0;
     uint8_t buf[BOOT_MAX_ALIGN];
-    size_t align;
+    uint32_t align;
     uint8_t erased_val;
 
     /* NOTE: The first sector copied (that is the last sector on slot) contains
@@ -498,12 +509,12 @@
 
 done:
     flash_area_close(fap);
+
     return rc;
 }
-#endif /* !MCUBOOT_RAM_LOAD */
-
 #endif /* MCUBOOT_SWAP_USING_STATUS */
 
+
 #endif /* !MCUBOOT_DIRECT_XIP */
 
 /*
@@ -515,7 +526,6 @@
 {
     TARGET_STATIC uint8_t tmpbuf[BOOT_TMPBUF_SZ];
     uint8_t image_index;
-    int rc;
     fih_int fih_rc = FIH_FAILURE;
 
 #if (BOOT_IMAGE_NUMBER == 1)
@@ -523,15 +533,14 @@
 #endif
 
     (void)bs;
-    (void)rc;
 
     image_index = BOOT_CURR_IMG(state);
 
 /* In the case of ram loading the image has already been decrypted as it is
  * decrypted when copied in ram */
-#if defined(MCUBOOT_ENC_IMAGES) && !defined(MCUBOOT_RAM_LOAD)
-    if (MUST_DECRYPT(fap, image_index, hdr)) {
-        rc = flash_area_id_to_multi_image_slot(image_index, fap->fa_id);
+#if defined(MCUBOOT_ENC_IMAGES)
+    if (MUST_DECRYPT(fap, image_index, hdr) && !IS_RAM_BOOTABLE(hdr)) {
+        int rc = flash_area_id_to_multi_image_slot(image_index, fap->fa_id);
         if (rc < 0) {
             FIH_RET(fih_rc);
         }
@@ -555,7 +564,6 @@
     FIH_RET(fih_rc);
 }
 
-#if !defined(MCUBOOT_DIRECT_XIP) && !defined(MCUBOOT_RAM_LOAD)
 static fih_int
 split_image_check(struct image_header *app_hdr,
                   const struct flash_area *app_fap,
@@ -575,7 +583,7 @@
 
     FIH_CALL(bootutil_img_validate, fih_rc, NULL, 0, loader_hdr, loader_fap,
              tmpbuf, BOOT_TMPBUF_SZ, NULL, 0, loader_hash);
-    if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
+    if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
         FIH_RET(fih_rc);
     }
 
@@ -585,7 +593,6 @@
 out:
     FIH_RET(fih_rc);
 }
-#endif /* !MCUBOOT_DIRECT_XIP && !MCUBOOT_RAM_LOAD */
 
 /*
  * Check that this is a valid header.  Valid means that the magic is
@@ -711,14 +718,13 @@
  *          does not match the slot address.
  */
 static bool
-boot_rom_address_check(struct boot_loader_state *state,
-                       struct slot_usage_t slot_usage[])
+boot_rom_address_check(struct boot_loader_state *state)
 {
     uint32_t active_slot;
     const struct image_header *hdr;
     uint32_t f_off;
 
-    active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
+    active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
     hdr = boot_img_hdr(state, active_slot);
     f_off = boot_img_slot_off(state, active_slot);
 
@@ -764,6 +770,7 @@
     BOOT_LOG_DBG("> boot_validate_slot: fa_id = %u", (unsigned)fap->fa_id);
 
     hdr = boot_img_hdr(state, slot);
+
     if (boot_check_header_erased(state, slot) == 0 ||
         (hdr->ih_flags & IMAGE_F_NON_BOOTABLE)) {
 
@@ -787,7 +794,7 @@
 
         BOOT_LOG_DBG(" * No bootable image in slot(%d); continue booting from the primary slot.", slot);
         /* No bootable image in slot; continue booting from the primary slot. */
-        fih_rc = fih_int_encode(1);
+        fih_rc = FIH_SWAP_TYPE_NONE;
         goto out;
     }
 
@@ -803,18 +810,18 @@
             /* Image in the secondary slot does not satisfy version requirement.
              * Erase the image and continue booting from the primary slot.
              */
-            fih_rc = fih_int_encode(1);
+            fih_rc = FIH_SWAP_TYPE_NONE;
             goto out;
         }
     }
 #endif
     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, fih_int_encode(BOOT_HOOK_REGULAR)))
+    if (FIH_TRUE == fih_eq(fih_rc, fih_int_encode(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 (!boot_is_header_valid(hdr, fap) || fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
         if ((slot != BOOT_PRIMARY_SLOT) || ARE_SLOTS_EQUIVALENT()) {
             BOOT_LOG_DBG(" * Image in the secondary slot is invalid. Erase the image");
             flash_area_erase(fap, 0, flash_area_get_size(fap));
@@ -826,15 +833,48 @@
         BOOT_LOG_ERR("Image in the %s slot is not valid!",
                      (slot == BOOT_PRIMARY_SLOT) ? "primary" : "secondary");
 #endif
-        fih_rc = fih_int_encode(1);
+        fih_rc = FIH_SWAP_TYPE_NONE;
         goto out;
     }
 
-    /* Image in the secondary slot is valid. */
+#if MCUBOOT_IMAGE_NUMBER > 1 && !defined(MCUBOOT_ENC_IMAGES) && defined(MCUBOOT_VERIFY_IMG_ADDRESS)
+    /* Verify that the image in the secondary slot has a reset address
+     * located in the primary slot. This is done to avoid users incorrectly
+     * overwriting an application written to the incorrect slot.
+     * This feature is only supported by ARM platforms.
+     */
+    if (area_id == FLASH_AREA_IMAGE_SECONDARY(BOOT_CURR_IMG(state))) {
+        const struct flash_area *pri_fa = BOOT_IMG_AREA(state, BOOT_PRIMARY_SLOT);
+        struct image_header *secondary_hdr = boot_img_hdr(state, slot);
+        uint32_t reset_value = 0;
+        uint32_t reset_addr = secondary_hdr->ih_hdr_size + sizeof(reset_value);
+
+        rc = flash_area_read(fap, reset_addr, &reset_value, sizeof(reset_value));
+        if (rc != 0) {
+            fih_rc = fih_int_encode(1);
+            goto out;
+        }
+
+        if (reset_value < pri_fa->fa_off || reset_value> (pri_fa->fa_off + pri_fa->fa_size)) {
+            BOOT_LOG_ERR("Reset address of image in secondary slot is not in the primary slot");
+            BOOT_LOG_ERR("Erasing image from secondary slot");
+
+            /* The vector table in the image located in the secondary
+             * slot does not target the primary slot. This might
+             * indicate that the image was loaded to the wrong slot.
+             *
+             * Erase the image and continue booting from the primary slot.
+             */
+            flash_area_erase(fap, 0, fap->fa_size);
+            fih_rc = fih_int_encode(1);
+            goto out;
+        }
+    }
+#endif
 
 out:
     flash_area_close(fap);
-    BOOT_LOG_DBG("< boot_validate_slot = %d", fih_int_decode(fih_rc));
+    BOOT_LOG_DBG("< boot_validate_slot: fa_id = %u", (unsigned)fap->fa_id);
     FIH_RET(fih_rc);
 }
 
@@ -857,12 +897,13 @@
                              struct image_header *hdr)
 {
     const struct flash_area *fap = NULL;
-    uint32_t img_security_cnt;
+    fih_int fih_rc = FIH_FAILURE;
+    fih_uint img_security_cnt = FIH_UINT_ZERO;
     void * custom_data = NULL;
     int rc;
-#ifdef CYW20829
+#if defined CYW20829
     uint8_t buff[REPROV_PACK_SIZE];
-#endif /* CYW20829 */
+#endif /* defined CYW20829 */
 
     rc = flash_area_open(flash_area_id_from_multi_image_slot(image_index, slot),
                          &fap);
@@ -871,26 +912,30 @@
         goto done;
     }
 
-    rc = bootutil_get_img_security_cnt(hdr, fap, &img_security_cnt);
-    if (rc != 0) {
+    rc = -1;
+    FIH_CALL(bootutil_get_img_security_cnt, fih_rc, hdr, fap, &img_security_cnt);
+    if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
         goto done;
     }
+    else 
+    {
+        fih_rc = FIH_FAILURE;
+    }
 
-#ifdef CYW20829
+#if defined CYW20829
     rc = bootutil_get_img_reprov_packet(hdr, fap, buff);
     if (rc == 0) {
         custom_data = (void *)buff;
     }
-#endif /* CYW20829 */
-    rc = boot_nv_security_counter_update(image_index, img_security_cnt, custom_data);
+#endif /* defined CYW20829 */
 
+    rc = boot_nv_security_counter_update(image_index, img_security_cnt, custom_data);
 done:
     flash_area_close(fap);
     return rc;
 }
 #endif /* MCUBOOT_HW_ROLLBACK_PROT */
 
-#if !defined(MCUBOOT_DIRECT_XIP) && !defined(MCUBOOT_RAM_LOAD)
 /**
  * Determines which swap operation to perform, if any.  If it is determined
  * that a swap operation is required, the image in the secondary slot is checked
@@ -912,8 +957,8 @@
          * Ensure image is valid.
          */
         FIH_CALL(boot_validate_slot, fih_rc, state, BOOT_SECONDARY_SLOT, bs);
-        if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
-            if (fih_eq(fih_rc, fih_int_encode(1))) {
+        if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
+            if (FIH_TRUE == fih_eq(fih_rc, FIH_SWAP_TYPE_NONE)) {
                 swap_type = BOOT_SWAP_TYPE_NONE;
             } else {
                 swap_type = BOOT_SWAP_TYPE_FAIL;
@@ -923,7 +968,6 @@
 
     return swap_type;
 }
-#endif
 
 /**
  * Erases a region of flash.
@@ -941,7 +985,6 @@
     return flash_area_erase(fap, off, sz);
 }
 
-#if !defined(MCUBOOT_DIRECT_XIP) && !defined(MCUBOOT_RAM_LOAD)
 /**
  * Copies the contents of one flash region to another.  You must erase the
  * destination region prior to calling this function.
@@ -1031,35 +1074,41 @@
             }
 #endif
             if (IS_ENCRYPTED(hdr)) {
-                blk_sz = chunk_sz;
-                idx = 0;
-                if (off + bytes_copied < hdr->ih_hdr_size) {
+                uint32_t abs_off = off + bytes_copied;
+                if (abs_off < hdr->ih_hdr_size) {
                     /* do not decrypt header */
-                    blk_off = 0;
-                    if(chunk_sz > hdr->ih_hdr_size) {
-                        blk_sz = chunk_sz - hdr->ih_hdr_size;
-                        idx = hdr->ih_hdr_size - (off + bytes_copied);
+                    if (abs_off + chunk_sz > hdr->ih_hdr_size) {
+                        /* The lower part of the chunk contains header data */
+                        blk_off = 0;
+                        blk_sz = chunk_sz - (hdr->ih_hdr_size - abs_off);
+                        idx = hdr->ih_hdr_size  - abs_off;
                     } else {
-                        /* still in header-area, no need to decrypt */
-                        blk_sz = 0;
+                        /* The chunk contains exclusively header data */
+                        blk_sz = 0; /* nothing to decrypt */
                     }
                 } else {
-                    blk_off = ((off + bytes_copied) - hdr->ih_hdr_size) & 0xf;
+                    idx = 0;
+                    blk_sz = chunk_sz;
+                    blk_off = (abs_off - hdr->ih_hdr_size) & 0xf;
                 }
-                tlv_off = BOOT_TLV_OFF(hdr);
-                if (off + bytes_copied + chunk_sz > tlv_off) {
-                    /* do not decrypt TLVs */
-                    if (off + bytes_copied >= tlv_off) {
-                        blk_sz = 0;
-                    } else {
-                        blk_sz = tlv_off - (off + bytes_copied);
+
+                if (blk_sz > 0)
+                {
+                    tlv_off = BOOT_TLV_OFF(hdr);
+                    if (abs_off + chunk_sz > tlv_off) {
+                        /* do not decrypt TLVs */
+                        if (abs_off >= tlv_off) {
+                            blk_sz = 0;
+                        } else {
+                            blk_sz = tlv_off - abs_off;
+                        }
                     }
-                }
-                rc = boot_encrypt(BOOT_CURR_ENC(state), image_index, fap_src,
-                    (off + bytes_copied + idx) - hdr->ih_hdr_size, blk_sz,
-                    blk_off, &buf[idx]);
-                if (rc != 0) {
-                    return rc;
+                    rc = boot_encrypt(BOOT_CURR_ENC(state), image_index, fap_src,
+                                      (abs_off + idx) - hdr->ih_hdr_size, blk_sz,
+                                      blk_off, &buf[idx]);
+                    if (rc != 0) {
+                        return rc;
+                    }
                 }
             }
         }
@@ -1297,7 +1346,7 @@
             }
         } else {
             (void)memset(bs->enckey[0], BOOT_UNINITIALIZED_KEY_FILL,
-                         BOOT_ENC_KEY_SIZE);
+                         BOOT_ENC_KEY_ALIGN_SIZE);
         }
 #endif
 
@@ -1322,7 +1371,7 @@
             }
         } else {
             (void)memset(bs->enckey[1], BOOT_UNINITIALIZED_KEY_FILL,
-                         BOOT_ENC_KEY_SIZE);
+                         BOOT_ENC_KEY_ALIGN_SIZE);
         }
 #endif
 
@@ -1381,8 +1430,7 @@
  * @return                  0 on success; nonzero on failure.
  */
 static int
-boot_verify_slot_dependency(struct boot_loader_state *state,
-                            struct image_dependency *dep)
+boot_verify_slot_dependency_flash(struct boot_loader_state *state, struct image_dependency *dep)
 {
     struct image_version *dep_version;
     size_t dep_slot;
@@ -1432,9 +1480,9 @@
  * @return                  0 on success; nonzero on failure.
  */
 static int
-boot_verify_slot_dependencies(struct boot_loader_state *state, uint32_t slot)
+boot_verify_slot_dependencies_flash(struct boot_loader_state *state, uint32_t slot)
 {
-    const struct flash_area *fap;
+    const struct flash_area *fap = NULL;
     struct image_tlv_iter it;
     struct image_dependency dep;
     uint32_t off;
@@ -1463,6 +1511,10 @@
             rc = 0;
             break;
         }
+        else
+        {
+            /* acc. to MISRA R.15.7 */
+        }
 
         if (len != sizeof(dep)) {
             rc = BOOT_EBADIMAGE;
@@ -1481,7 +1533,7 @@
         }
 
         /* Verify dependency and modify the swap type if not satisfied. */
-        rc = boot_verify_slot_dependency(state, &dep);
+        rc = boot_verify_slot_dependency_flash(state, &dep);
         if (rc != 0) {
             /* Dependency not satisfied. */
             goto done;
@@ -1498,13 +1550,17 @@
  * TLV area are all satisfied and update the related swap type if necessary.
  */
 static int
-boot_verify_dependencies(struct boot_loader_state *state)
+boot_verify_dependencies_flash(struct boot_loader_state *state)
 {
     int rc = -1;
     uint8_t slot;
 
     BOOT_CURR_IMG(state) = 0;
     while (BOOT_CURR_IMG(state) < BOOT_IMAGE_NUMBER) {
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            BOOT_CURR_IMG(state)++;
+            continue;
+        }
         if (BOOT_SWAP_TYPE(state) != BOOT_SWAP_TYPE_NONE &&
             BOOT_SWAP_TYPE(state) != BOOT_SWAP_TYPE_FAIL) {
             slot = BOOT_SECONDARY_SLOT;
@@ -1512,7 +1568,7 @@
             slot = BOOT_PRIMARY_SLOT;
         }
 
-        rc = boot_verify_slot_dependencies(state, slot);
+        rc = boot_verify_slot_dependencies_flash(state, slot);
         if (rc == 0) {
             /* All dependencies've been satisfied, continue with next image. */
             BOOT_CURR_IMG(state)++;
@@ -1565,7 +1621,7 @@
     fih_int fih_rc = FIH_FAILURE;
     rc = boot_check_header_erased(state, BOOT_PRIMARY_SLOT);
     FIH_CALL(boot_validate_slot, fih_rc, state, BOOT_PRIMARY_SLOT, bs);
-    if (rc == 0 || fih_not_eq(fih_rc, FIH_SUCCESS)) {
+    if (rc == 0 || fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
         /* Initialize swap status partition for primary slot, because
          * in swap mode it is needed to properly complete copying the image
          * to the primary slot.
@@ -1802,6 +1858,45 @@
         boot_status_reset(bs);
 
 #ifndef MCUBOOT_OVERWRITE_ONLY
+#ifdef MCUBOOT_SWAP_USING_STATUS
+
+        const struct flash_area *fap;
+        uint32_t img_size = 0;
+
+        /* Check here if image firmware + tlvs in slot do not
+         * overlap with last sector of slot. Last sector of slot
+         * contains trailer of the image which needs to be
+         * manupulated independently of other image parts. 
+         * If firmware overlaps with trailer sector it does not 
+         * make sense to move further since any attemps to perform
+         * swap upgrade would lead to failure or unexpected behaviour
+         */
+
+        for (uint32_t i = 0; i < BOOT_NUM_SLOTS; i++) {
+
+            rc = boot_read_image_size(state, i, &img_size);
+
+            if (rc == 0) {
+                fap = BOOT_IMG(state, i).area;
+                if (fap != NULL) {
+
+                    uint32_t trailer_sector_off = (BOOT_WRITE_SZ(state)) * boot_img_num_sectors(state, i) - BOOT_WRITE_SZ(state);
+
+                    BOOT_LOG_DBG("Slot %u firmware + tlvs size = %u, slot size = %u, write_size = %u, write_size * sect_num - write_size = %u",
+                                        i , img_size, fap->fa_size, BOOT_WRITE_SZ(state), trailer_sector_off);
+
+                    if (img_size > trailer_sector_off) {
+                        BOOT_LOG_ERR("Firmware + tlvs in slot %u overlaps with last sector, which contains trailer, erasing this image", i);
+                        rc = flash_area_erase(fap, 0, flash_area_get_size(fap));
+                    }
+                    else {
+                        /* image firmware + tlvs do not overlap with last sector of slot, continue */
+                    }
+                }
+            }
+        }
+#endif /* MCUBOOT_SWAP_USING_STATUS */
+
         rc = swap_read_status(state, bs);
         if (rc != 0) {
             BOOT_LOG_WRN("Failed reading boot status; Image=%u",
@@ -1873,7 +1968,7 @@
             } else {
                 FIH_CALL(boot_validate_slot, fih_rc,
                          state, BOOT_SECONDARY_SLOT, bs);
-                if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
+                if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
                     BOOT_SWAP_TYPE(state) = BOOT_SWAP_TYPE_FAIL;
                 } else {
                     BOOT_SWAP_TYPE(state) = bs->swap_type;
@@ -1896,13 +1991,13 @@
                 FIH_CALL(boot_validate_slot, fih_rc,
                          state, BOOT_PRIMARY_SLOT, bs);
 
-                if (rc == 0 || fih_not_eq(fih_rc, FIH_SUCCESS)) {
+                if (rc == 0 || fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
 
                     rc = (boot_img_hdr(state, BOOT_SECONDARY_SLOT)->ih_magic == IMAGE_MAGIC) ? 1: 0;
                     FIH_CALL(boot_validate_slot, fih_rc,
                              state, BOOT_SECONDARY_SLOT, bs);
 
-                    if (rc == 1 && fih_eq(fih_rc, FIH_SUCCESS)) {
+                    if (rc == 1 && FIH_TRUE == fih_eq(fih_rc, FIH_SUCCESS)) {
                         /* Set swap type to REVERT to overwrite the primary
                          * slot with the image contained in secondary slot
                          * and to trigger the explicit setting of the
@@ -1929,7 +2024,7 @@
  * @return              0 on success; nonzero on failure.
  */
 static int
-boot_update_hw_rollback_protection(struct boot_loader_state *state)
+boot_update_hw_rollback_protection_flash(struct boot_loader_state *state)
 {
 #ifdef MCUBOOT_HW_ROLLBACK_PROT
     int rc;
@@ -1966,10 +2061,10 @@
 }
 
 fih_int
-context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp)
+context_boot_go_flash(struct boot_loader_state *state, struct boot_rsp *rsp)
 {
     size_t slot;
-    struct boot_status bs;
+    struct boot_status bs = {0};
     int rc = -1;
     fih_int fih_rc = FIH_FAILURE;
     int fa_id;
@@ -1990,8 +2085,6 @@
     TARGET_STATIC boot_sector_t status_sectors[BOOT_MAX_SWAP_STATUS_SECTORS];
 #endif
 
-    (void)memset(&bs, 0, sizeof(bs));
-    (void)memset(state, 0, sizeof(struct boot_loader_state));
     has_upgrade = false;
 
 #if (BOOT_IMAGE_NUMBER == 1)
@@ -2003,7 +2096,11 @@
      * completed.
      */
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
-
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
 #if defined(MCUBOOT_ENC_IMAGES) && (BOOT_IMAGE_NUMBER > 1)
         /* The keys used for encryption may no longer be valid (could belong to
          * another images). Therefore, mark them as invalid to force their reload
@@ -2053,7 +2150,7 @@
         /* Iterate over all the images and verify whether the image dependencies
          * are all satisfied and update swap type if necessary.
          */
-        rc = boot_verify_dependencies(state);
+        rc = boot_verify_dependencies_flash(state);
         if (rc != 0) {
             /*
              * It was impossible to upgrade because the expected dependency version
@@ -2071,8 +2168,11 @@
      * all required update operations will have been finished.
      */
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
-
 #if (BOOT_IMAGE_NUMBER > 1)
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+
 #ifdef MCUBOOT_ENC_IMAGES
         /* The keys used for encryption may no longer be valid (could belong to
          * another images). Therefore, mark them as invalid to force their reload
@@ -2142,6 +2242,11 @@
      * have been re-validated.
      */
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
         if (BOOT_SWAP_TYPE(state) != BOOT_SWAP_TYPE_NONE) {
             /* Attempt to read an image header from each slot. Ensure that image
              * headers in slots are aligned with headers in boot_data.
@@ -2159,7 +2264,7 @@
 
 #ifdef MCUBOOT_VALIDATE_PRIMARY_SLOT
         FIH_CALL(boot_validate_slot, fih_rc, state, BOOT_PRIMARY_SLOT, &bs);
-        if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
+        if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
             goto out;
         }
 #else
@@ -2186,7 +2291,7 @@
         }
 #endif /* MCUBOOT_ENC_IMAGES_XIP */
 
-        rc = boot_update_hw_rollback_protection(state);
+        rc = boot_update_hw_rollback_protection_flash(state);
         if (rc != 0) {
             goto out;
         }
@@ -2212,7 +2317,7 @@
      */
     (void)memset(&bs, 0, sizeof(struct boot_status));
 
-    fill_rsp(state, NULL, rsp);
+    fill_rsp(state, rsp);
 
     fih_rc = FIH_SUCCESS;
 out:
@@ -2276,7 +2381,7 @@
              BOOT_IMG_AREA(&boot_data, split_slot),
              boot_img_hdr(&boot_data, loader_slot),
              BOOT_IMG_AREA(&boot_data, loader_slot));
-    if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
+    if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
         goto done;
     }
 
@@ -2297,22 +2402,18 @@
     FIH_RET(fih_rc);
 }
 
-#else /* MCUBOOT_DIRECT_XIP || MCUBOOT_RAM_LOAD */
 
-#define NO_ACTIVE_SLOT UINT32_MAX
+#if defined(MCUBOOT_DIRECT_XIP) || defined(MCUBOOT_RAM_LOAD)
 
 /**
  * Opens all flash areas and checks which contain an image with a valid header.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Structure to fill with information about the available
- *                      slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 static int
-boot_get_slot_usage(struct boot_loader_state *state,
-                    struct slot_usage_t slot_usage[])
+boot_get_slot_usage(struct boot_loader_state *state)
 {
     uint32_t slot;
     int fa_id;
@@ -2320,6 +2421,11 @@
     struct image_header *hdr = NULL;
 
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
         /* Open all the slots */
         for (slot = 0; slot < BOOT_NUM_SLOTS; slot++) {
             fa_id = flash_area_id_from_multi_image_slot(
@@ -2340,10 +2446,10 @@
             hdr = boot_img_hdr(state, slot);
 
             if (boot_is_header_valid(hdr, BOOT_IMG_AREA(state, slot))) {
-                slot_usage[BOOT_CURR_IMG(state)].slot_available[slot] = true;
+                state->slot_usage[BOOT_CURR_IMG(state)].slot_available[slot] = true;
                 BOOT_LOG_IMAGE_INFO(slot, hdr);
             } else {
-                slot_usage[BOOT_CURR_IMG(state)].slot_available[slot] = false;
+                state->slot_usage[BOOT_CURR_IMG(state)].slot_available[slot] = false;
                 BOOT_LOG_INF("Image %u %s slot: Image not found",
                              (unsigned)BOOT_CURR_IMG(state),
                              (slot == BOOT_PRIMARY_SLOT)
@@ -2351,7 +2457,7 @@
             }
         }
 
-        slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
+        state->slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
     }
 
     return 0;
@@ -2362,21 +2468,19 @@
  * current image.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              NO_ACTIVE_SLOT if no available slot found, number of
  *                      the found slot otherwise.
  */
 static uint32_t
-find_slot_with_highest_version(struct boot_loader_state *state,
-                               struct slot_usage_t slot_usage[])
+find_slot_with_highest_version(struct boot_loader_state *state)
 {
     uint32_t slot;
     uint32_t candidate_slot = NO_ACTIVE_SLOT;
     int rc;
 
     for (slot = 0; slot < BOOT_NUM_SLOTS; slot++) {
-        if (slot_usage[BOOT_CURR_IMG(state)].slot_available[slot]) {
+        if (state->slot_usage[BOOT_CURR_IMG(state)].slot_available[slot]) {
             if (candidate_slot == NO_ACTIVE_SLOT) {
                 candidate_slot = slot;
             } else {
@@ -2401,18 +2505,21 @@
  * Prints the state of the loaded images.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  */
 static void
-print_loaded_images(struct boot_loader_state *state,
-                    struct slot_usage_t slot_usage[])
+print_loaded_images(struct boot_loader_state *state)
 {
     uint32_t active_slot;
 
     (void)state;
 
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
-        active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
+        active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
 
         BOOT_LOG_INF("Image %u loaded from the %s slot",
                      (unsigned)BOOT_CURR_IMG(state),
@@ -2429,13 +2536,11 @@
  * otherwise marks it as selected if it has not been before.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 static int
-boot_select_or_erase(struct boot_loader_state *state,
-                     struct slot_usage_t slot_usage[])
+boot_select_or_erase(struct boot_loader_state *state)
 {
     const struct flash_area *fap;
     int fa_id;
@@ -2443,13 +2548,13 @@
     uint32_t active_slot;
     struct boot_swap_state* active_swap_state;
 
-    active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
+    active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
 
     fa_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state), active_slot);
     rc = flash_area_open(fa_id, &fap);
     assert(rc == 0);
 
-    active_swap_state = &(slot_usage[BOOT_CURR_IMG(state)].swap_state);
+    active_swap_state = &(state->slot_usage[BOOT_CURR_IMG(state)].swap_state);
 
     (void)memset(active_swap_state, 0, sizeof(struct boot_swap_state));
     rc = boot_read_swap_state(fap, active_swap_state);
@@ -2510,13 +2615,11 @@
  * predefined bounds that are allowed to be used by executable images.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 static int
-boot_verify_ram_load_address(struct boot_loader_state *state,
-                             struct slot_usage_t slot_usage[])
+boot_verify_ram_load_address(struct boot_loader_state *state)
 {
     uint32_t img_dst;
     uint32_t img_sz;
@@ -2539,8 +2642,8 @@
     exec_ram_size = IMAGE_EXECUTABLE_RAM_SIZE;
 #endif
 
-    img_dst = slot_usage[BOOT_CURR_IMG(state)].img_dst;
-    img_sz = slot_usage[BOOT_CURR_IMG(state)].img_sz;
+    img_dst = state->slot_usage[BOOT_CURR_IMG(state)].img_dst;
+    img_sz = state->slot_usage[BOOT_CURR_IMG(state)].img_sz;
 
     if (img_dst < exec_ram_start) {
         return BOOT_EBADIMAGE;
@@ -2732,14 +2835,12 @@
  * Checks if the image we want to load to memory overlap with an already
  * ramloaded image.
  *
- * @param  slot_usage         Information about the active and available slots.
- * @param  image_id_to_check  The ID of the image we would like to load.
+ * @param  state    Boot loader status information.
  *
  * @return                    0 if there is no overlap; nonzero otherwise.
  */
 static int
-boot_check_ram_load_overlapping(struct slot_usage_t slot_usage[],
-                                uint32_t image_id_to_check)
+boot_check_ram_load_overlapping(struct boot_loader_state *state)
 {
     uint32_t i;
 
@@ -2747,22 +2848,23 @@
     uint32_t end_a;
     uint32_t start_b;
     uint32_t end_b;
+    uint32_t image_id_to_check = BOOT_CURR_IMG(state);
 
-    start_a = slot_usage[image_id_to_check].img_dst;
+    start_a = state->slot_usage[image_id_to_check].img_dst;
     /* Safe to add here, values are already verified in
      * boot_verify_ram_load_address() */
-    end_a = start_a + slot_usage[image_id_to_check].img_sz;
+    end_a = start_a + state->slot_usage[image_id_to_check].img_sz;
 
     for (i = 0; i < BOOT_IMAGE_NUMBER; i++) {
-        if (slot_usage[i].active_slot == NO_ACTIVE_SLOT
+        if (state->slot_usage[i].active_slot == NO_ACTIVE_SLOT
             || i == image_id_to_check) {
             continue;
         }
 
-        start_b = slot_usage[i].img_dst;
+        start_b = state->slot_usage[i].img_dst;
         /* Safe to add here, values are already verified in
          * boot_verify_ram_load_address() */
-        end_b = start_b + slot_usage[i].img_sz;
+        end_b = start_b + state->slot_usage[i].img_sz;
 
         if (do_regions_overlap(start_a, end_a, start_b, end_b)) {
             return -1;
@@ -2778,24 +2880,22 @@
  * image size is extracted from the image header.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 static int
-boot_load_image_to_sram(struct boot_loader_state *state,
-                        struct slot_usage_t slot_usage[])
+boot_load_image_to_sram(struct boot_loader_state *state)
 {
     uint32_t active_slot;
     struct image_header *hdr = NULL;
     uint32_t img_dst;
     uint32_t img_sz;
-    int rc;
+    int rc = 0;
 
-    active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
+    active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
     hdr = boot_img_hdr(state, active_slot);
 
-    if (hdr->ih_flags & IMAGE_F_RAM_LOAD) {
+    if (IS_RAM_BOOTABLE(hdr)) {
 
         img_dst = hdr->ih_load_addr;
 
@@ -2804,17 +2904,17 @@
             return rc;
         }
 
-        slot_usage[BOOT_CURR_IMG(state)].img_dst = img_dst;
-        slot_usage[BOOT_CURR_IMG(state)].img_sz = img_sz;
+        state->slot_usage[BOOT_CURR_IMG(state)].img_dst = img_dst;
+        state->slot_usage[BOOT_CURR_IMG(state)].img_sz = img_sz;
 
-        rc = boot_verify_ram_load_address(state, slot_usage);
+        rc = boot_verify_ram_load_address(state);
         if (rc != 0) {
             BOOT_LOG_INF("Image RAM load address 0x%" PRIx32 " is invalid.", img_dst);
             return rc;
         }
 
 #if (BOOT_IMAGE_NUMBER > 1)
-        rc = boot_check_ram_load_overlapping(slot_usage, BOOT_CURR_IMG(state));
+        rc = boot_check_ram_load_overlapping(state);
         if (rc != 0) {
             BOOT_LOG_INF("Image RAM loading to address 0x%" PRIx32
                          " would overlap with another image.", img_dst);
@@ -2839,7 +2939,8 @@
         } else {
             BOOT_LOG_INF("RAM loading to 0x%" PRIx32 " is succeeded.", img_dst);
         }
-    } else {
+    }
+    else {
         /* Only images that support IMAGE_F_RAM_LOAD are allowed if
          * MCUBOOT_RAM_LOAD is set.
          */
@@ -2847,8 +2948,8 @@
     }
 
     if (rc != 0) {
-        slot_usage[BOOT_CURR_IMG(state)].img_dst = 0;
-        slot_usage[BOOT_CURR_IMG(state)].img_sz = 0;
+        state->slot_usage[BOOT_CURR_IMG(state)].img_dst = 0;
+        state->slot_usage[BOOT_CURR_IMG(state)].img_sz = 0;
     }
 
     return rc;
@@ -2858,24 +2959,22 @@
  * Removes an image from SRAM, by overwriting it with zeros.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 static inline int
-boot_remove_image_from_sram(struct boot_loader_state *state,
-                            struct slot_usage_t slot_usage[])
+boot_remove_image_from_sram(struct boot_loader_state *state)
 {
     (void)state;
 
-    BOOT_LOG_INF("Removing image from SRAM at address 0x%" PRIx32,
-                 slot_usage[BOOT_CURR_IMG(state)].img_dst);
+    BOOT_LOG_INF("Removing image from SRAM at address 0x%x",
+                 state->slot_usage[BOOT_CURR_IMG(state)].img_dst);
 
-    memset((void*)(IMAGE_RAM_BASE + slot_usage[BOOT_CURR_IMG(state)].img_dst),
-           0, slot_usage[BOOT_CURR_IMG(state)].img_sz);
+    (void)memset((void*)(IMAGE_RAM_BASE + state->slot_usage[BOOT_CURR_IMG(state)].img_dst),
+           0, state->slot_usage[BOOT_CURR_IMG(state)].img_sz);
 
-    slot_usage[BOOT_CURR_IMG(state)].img_dst = 0;
-    slot_usage[BOOT_CURR_IMG(state)].img_sz = 0;
+    state->slot_usage[BOOT_CURR_IMG(state)].img_dst = 0;
+    state->slot_usage[BOOT_CURR_IMG(state)].img_sz = 0;
 
     return 0;
 }
@@ -2914,14 +3013,12 @@
  * Checks the image dependency whether it is satisfied.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  * @param  dep          Image dependency which has to be verified.
  *
  * @return              0 if dependencies are met; nonzero otherwise.
  */
 static int
-boot_verify_slot_dependency(struct boot_loader_state *state,
-                            struct slot_usage_t  slot_usage[],
+boot_verify_slot_dependency_ram(struct boot_loader_state *state,
                             struct image_dependency *dep)
 {
     struct image_version *dep_version;
@@ -2931,7 +3028,7 @@
     /* Determine the source of the image which is the subject of
      * the dependency and get it's version.
      */
-    dep_slot = slot_usage[dep->image_id].active_slot;
+    dep_slot = state->slot_usage[dep->image_id].active_slot;
     dep_version = &state->imgs[dep->image_id][dep_slot].hdr.ih_ver;
 
     rc = boot_version_cmp(dep_version, &dep->image_min_version);
@@ -2948,13 +3045,11 @@
  * if they are all satisfied.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 if dependencies are met; nonzero otherwise.
  */
 static int
-boot_verify_slot_dependencies(struct boot_loader_state *state,
-                              struct slot_usage_t slot_usage[])
+boot_verify_slot_dependencies_ram(struct boot_loader_state *state)
 {
     uint32_t active_slot;
     const struct flash_area *fap;
@@ -2965,7 +3060,7 @@
     int area_id;
     int rc;
 
-    active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
+    active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
 
     area_id = flash_area_id_from_multi_image_slot(BOOT_CURR_IMG(state),
                                                                 active_slot);
@@ -3007,7 +3102,7 @@
             goto done;
         }
 
-        rc = boot_verify_slot_dependency(state, slot_usage, &dep);
+        rc = boot_verify_slot_dependency_ram(state, &dep);
         if (rc != 0) {
             /* Dependency not satisfied. */
             goto done;
@@ -3025,29 +3120,30 @@
  * case of MCUBOOT_RAM_LOAD strategy) and its slot is set to unavailable.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 if dependencies are met; nonzero otherwise.
  */
 static int
-boot_verify_dependencies(struct boot_loader_state *state,
-                         struct slot_usage_t slot_usage[])
+boot_verify_dependencies_ram(struct boot_loader_state *state)
 {
     int rc = -1;
     uint32_t active_slot;
 
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
-        rc = boot_verify_slot_dependencies(state, slot_usage);
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+        rc = boot_verify_slot_dependencies_ram(state);
         if (rc != 0) {
             /* Dependencies not met or invalid dependencies. */
 
 #ifdef MCUBOOT_RAM_LOAD
-            boot_remove_image_from_sram(state, slot_usage);
+            boot_remove_image_from_sram(state);
 #endif /* MCUBOOT_RAM_LOAD */
 
-            active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
-            slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
-            slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
+            active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
+            state->slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
+            state->slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
 
             return rc;
         }
@@ -3061,13 +3157,11 @@
  * Tries to load a slot for all the images with validation.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 fih_int
-boot_load_and_validate_images(struct boot_loader_state *state,
-                              struct slot_usage_t slot_usage[])
+boot_load_and_validate_images(struct boot_loader_state *state)
 {
     uint32_t active_slot;
     int rc;
@@ -3079,16 +3173,14 @@
          * means that a valid image found or already loaded. If no slot is
          * found the function returns with error code. */
         while (true) {
-
             /* Go over all the slots and try to load one */
-            active_slot = slot_usage[BOOT_CURR_IMG(state)].active_slot;
+            active_slot = state->slot_usage[BOOT_CURR_IMG(state)].active_slot;
             if (active_slot != NO_ACTIVE_SLOT){
                 /* A slot is already active, go to next image. */
                 break;
             }
 
-            active_slot = find_slot_with_highest_version(state,
-                                                         slot_usage);
+            active_slot = find_slot_with_highest_version(state);
             if (active_slot == NO_ACTIVE_SLOT) {
                 BOOT_LOG_INF("No slot to load for image %u",
                              (unsigned)BOOT_CURR_IMG(state));
@@ -3096,23 +3188,29 @@
             }
 
             /* Save the number of the active slot. */
-            slot_usage[BOOT_CURR_IMG(state)].active_slot = active_slot;
+            state->slot_usage[BOOT_CURR_IMG(state)].active_slot = active_slot;
+
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
 
 #ifdef MCUBOOT_DIRECT_XIP
-            rc = boot_rom_address_check(state, slot_usage);
+            rc = boot_rom_address_check(state);
             if (rc != 0) {
                 /* The image is placed in an unsuitable slot. */
-                slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
-                slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
+                state->slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
+                state->slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
                 continue;
             }
 
 #ifdef MCUBOOT_DIRECT_XIP_REVERT
-            rc = boot_select_or_erase(state, slot_usage);
+            rc = boot_select_or_erase(state);
             if (rc != 0) {
                 /* The selected image slot has been erased. */
-                slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
-                slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
+                state->slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
+                state->slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
                 continue;
             }
 #endif /* MCUBOOT_DIRECT_XIP_REVERT */
@@ -3124,24 +3222,24 @@
              * when loading images from external (untrusted) flash to internal
              * (trusted) RAM and image is authenticated before copying.
              */
-            rc = boot_load_image_to_sram(state, slot_usage);
+            rc = boot_load_image_to_sram(state);
             if (rc != 0 ) {
                 /* Image cannot be ramloaded. */
                 boot_remove_image_from_flash(state, active_slot);
-                slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
-                slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
+                state->slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
+                state->slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
                 continue;
             }
 #endif /* MCUBOOT_RAM_LOAD */
 
             FIH_CALL(boot_validate_slot, fih_rc, state, active_slot, NULL);
-            if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
+            if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
                 /* Image is invalid. */
 #ifdef MCUBOOT_RAM_LOAD
-                boot_remove_image_from_sram(state, slot_usage);
+                boot_remove_image_from_sram(state);
 #endif /* MCUBOOT_RAM_LOAD */
-                slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
-                slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
+                state->slot_usage[BOOT_CURR_IMG(state)].slot_available[active_slot] = false;
+                state->slot_usage[BOOT_CURR_IMG(state)].active_slot = NO_ACTIVE_SLOT;
                 continue;
             }
 
@@ -3150,6 +3248,7 @@
         }
     }
 
+    (void) rc;
     FIH_RET(FIH_SUCCESS);
 }
 
@@ -3157,13 +3256,11 @@
  * Updates the security counter for the current image.
  *
  * @param  state        Boot loader status information.
- * @param  slot_usage   Information about the active and available slots.
  *
  * @return              0 on success; nonzero on failure.
  */
 static int
-boot_update_hw_rollback_protection(struct boot_loader_state *state,
-                                   const struct slot_usage_t slot_usage[])
+boot_update_hw_rollback_protection_ram(struct boot_loader_state *state)
 {
 #ifdef MCUBOOT_HW_ROLLBACK_PROT
     int rc;
@@ -3177,11 +3274,11 @@
      * has been confirmed at runtime (the image_ok flag has been set).
      * This way a 'revert' can be performed when it's necessary.
      */
-    if (slot_usage[BOOT_CURR_IMG(state)].swap_state.image_ok == BOOT_FLAG_SET) {
+    if (state->slot_usage[BOOT_CURR_IMG(state)].swap_state.image_ok == BOOT_FLAG_SET) {
 #endif
         rc = boot_update_security_counter(BOOT_CURR_IMG(state),
-                                          slot_usage[BOOT_CURR_IMG(state)].active_slot,
-                                          boot_img_hdr(state, slot_usage[BOOT_CURR_IMG(state)].active_slot));
+                                          state->slot_usage[BOOT_CURR_IMG(state)].active_slot,
+                                          boot_img_hdr(state, state->slot_usage[BOOT_CURR_IMG(state)].active_slot));
         if (rc != 0) {
             BOOT_LOG_ERR("Security counter update failed after image "
                             "validation.");
@@ -3195,22 +3292,17 @@
 
 #else /* MCUBOOT_HW_ROLLBACK_PROT */
     (void) (state);
-    (void) (slot_usage);
     return 0;
 #endif
 }
 
 fih_int
-context_boot_go(struct boot_loader_state *state, struct boot_rsp *rsp)
+context_boot_go_ram(struct boot_loader_state *state, struct boot_rsp *rsp)
 {
-    struct slot_usage_t slot_usage[BOOT_IMAGE_NUMBER];
     int rc;
-    fih_int fih_rc = fih_int_encode(0);
+    fih_int fih_rc = FIH_FAILURE;
 
-    memset(state, 0, sizeof(struct boot_loader_state));
-    memset(slot_usage, 0, sizeof(struct slot_usage_t) * BOOT_IMAGE_NUMBER);
-
-    rc = boot_get_slot_usage(state, slot_usage);
+    rc = boot_get_slot_usage(state);
     if (rc != 0) {
         goto out;
     }
@@ -3218,13 +3310,13 @@
 #if (BOOT_IMAGE_NUMBER > 1)
     while (true) {
 #endif
-        FIH_CALL(boot_load_and_validate_images, fih_rc, state, slot_usage);
-        if (fih_not_eq(fih_rc, FIH_SUCCESS)) {
+        FIH_CALL(boot_load_and_validate_images, fih_rc, state);
+        if (fih_eq(fih_rc, FIH_SUCCESS) != FIH_TRUE) {
             goto out;
         }
 
 #if (BOOT_IMAGE_NUMBER > 1)
-        rc = boot_verify_dependencies(state, slot_usage);
+        rc = boot_verify_dependencies_ram(state);
         if (rc != 0) {
             /* Dependency check failed for an image, it has been removed from
              * SRAM in case of MCUBOOT_RAM_LOAD strategy, and set to
@@ -3238,12 +3330,17 @@
 #endif
 
     IMAGES_ITER(BOOT_CURR_IMG(state)) {
-        rc = boot_update_hw_rollback_protection(state, slot_usage);
+#if BOOT_IMAGE_NUMBER > 1
+        if (state->img_mask[BOOT_CURR_IMG(state)]) {
+            continue;
+        }
+#endif
+        rc = boot_update_hw_rollback_protection_ram(state);
         if (rc != 0) {
             goto out;
         }
 
-        rc = boot_add_shared_data(state, slot_usage[BOOT_CURR_IMG(state)].active_slot);
+        rc = boot_add_shared_data(state, state->slot_usage[BOOT_CURR_IMG(state)].active_slot);
         if (rc != 0) {
             goto out;
         }
@@ -3251,16 +3348,16 @@
 
     /* All image loaded successfully. */
 #ifdef MCUBOOT_HAVE_LOGGING
-    print_loaded_images(state, slot_usage);
+    print_loaded_images(state);
 #endif
 
-    fill_rsp(state, slot_usage, rsp);
+    fill_rsp(state, rsp);
 
 out:
     close_all_flash_areas(state);
 
-    if (fih_eq(fih_rc, FIH_SUCCESS)) {
-        fih_rc = fih_int_encode(rc);
+    if (FIH_TRUE == fih_eq(fih_rc, FIH_SUCCESS)) {
+        fih_rc = fih_int_encode_zero_equality(rc);
     }
 
     FIH_RET(fih_rc);
@@ -3279,6 +3376,87 @@
 boot_go(struct boot_rsp *rsp)
 {
     fih_int fih_rc = FIH_FAILURE;
-    FIH_CALL(context_boot_go, fih_rc, &boot_data, rsp);
+
+    boot_state_clear(NULL);
+
+    FIH_CALL(context_boot_go_flash, fih_rc, &boot_data, rsp);
     FIH_RET(fih_rc);
 }
+
+/**
+ * Prepares the booting process, considering only a single image. This function
+ * moves images around in flash as appropriate, and tells you what address to
+ * boot from.
+ *
+ * @param rsp                   On success, indicates how booting should occur.
+ *
+ * @param image_id              The image ID to prepare the boot process for.
+ *
+ * @return                      FIH_SUCCESS on success; nonzero on failure.
+ */
+fih_int
+boot_go_for_image_id(struct boot_rsp *rsp, uint32_t image_id)
+{
+    fih_int fih_rc = FIH_FAILURE;
+
+    if (image_id >= BOOT_IMAGE_NUMBER) {
+        FIH_RET(FIH_FAILURE);
+    }
+
+#if BOOT_IMAGE_NUMBER > 1
+    (void)memset(&boot_data.img_mask, 1, BOOT_IMAGE_NUMBER);
+    boot_data.img_mask[image_id] = 0;
+#endif
+
+    FIH_CALL(context_boot_go_flash, fih_rc, &boot_data, rsp);
+    FIH_RET(fih_rc);
+}
+
+#if defined(MCUBOOT_RAM_LOAD)
+/**
+ * Prepares the booting process, considering only a single image. This function
+ * moves images around in flash as appropriate, and tells you what address to
+ * boot from.
+ *
+ * @param rsp                   On success, indicates how booting should occur.
+ *
+ * @param image_id              The image ID to prepare the boot process for.
+ *
+ * @return                      FIH_SUCCESS on success; nonzero on failure.
+ */
+fih_int
+boot_go_for_image_id_ram(struct boot_rsp *rsp, uint32_t image_id)
+{
+    fih_int fih_rc = FIH_FAILURE;
+
+    if (image_id >= BOOT_IMAGE_NUMBER) {
+        FIH_RET(FIH_FAILURE);
+    }
+
+#if BOOT_IMAGE_NUMBER > 1
+    (void)memset(&boot_data.img_mask, 1, BOOT_IMAGE_NUMBER);
+    boot_data.img_mask[image_id] = 0;
+#endif
+
+    FIH_CALL(context_boot_go_ram, fih_rc, &boot_data, rsp);
+    FIH_RET(fih_rc);
+}
+
+#endif /* MCUBOOT_RAM_LOAD */
+
+/**
+ * Clears the boot state, so that previous operations have no effect on new
+ * ones.
+ *
+ * @param state                 The state that should be cleared. If the value
+ *                              is NULL, the default bootloader state will be
+ *                              cleared.
+ */
+void boot_state_clear(struct boot_loader_state *state)
+{
+    if (state != NULL) {
+        (void)memset(state, 0, sizeof(struct boot_loader_state));
+    } else {
+        (void)memset(&boot_data, 0, sizeof(struct boot_loader_state));
+    }
+}