diff --git a/components/spi_flash/sim/stubs/log/include/esp_log.h b/components/spi_flash/sim/stubs/log/include/esp_log.h
index 6c9bb6f75..68cd216bc 100644
--- a/components/spi_flash/sim/stubs/log/include/esp_log.h
+++ b/components/spi_flash/sim/stubs/log/include/esp_log.h
@@ -44,11 +44,13 @@ void esp_log_write(esp_log_level_t level, const char* tag, const char* format, .
 
 #define ESP_LOGE( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_ERROR)   { esp_log_write(ESP_LOG_ERROR,   tag, LOG_FORMAT(E, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
 
-#define ESP_LOGV( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_VERBOSE) { esp_log_write(ESP_LOG_VERBOSE, tag, LOG_FORMAT(V, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
+#define ESP_LOGW( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_WARN)    { esp_log_write(ESP_LOG_WARN,    tag, LOG_FORMAT(W, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
+
+#define ESP_LOGI( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_INFO)    { esp_log_write(ESP_LOG_INFO,    tag, LOG_FORMAT(E, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
 
 #define ESP_LOGD( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG)   { esp_log_write(ESP_LOG_DEBUG,   tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
 
-#define ESP_LOGW( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_WARN)    { esp_log_write(ESP_LOG_WARN,    tag, LOG_FORMAT(W, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
+#define ESP_LOGV( tag, format, ... )  if (LOG_LOCAL_LEVEL >= ESP_LOG_VERBOSE) { esp_log_write(ESP_LOG_VERBOSE, tag, LOG_FORMAT(V, format), esp_log_timestamp(), tag, ##__VA_ARGS__); }
 
 // Assume that flash encryption is not enabled. Put here since in partition.c
 // esp_log.h is included later than esp_flash_encrypt.h.
diff --git a/components/wear_levelling/WL_Flash.cpp b/components/wear_levelling/WL_Flash.cpp
index fec527a62..28e5d6480 100644
--- a/components/wear_levelling/WL_Flash.cpp
+++ b/components/wear_levelling/WL_Flash.cpp
@@ -12,11 +12,13 @@
 // limitations under the License.
 
 #include <stdio.h>
+#include "esp_system.h"
 #include "esp_log.h"
 #include "WL_Flash.h"
 #include <stdlib.h>
 #include "crc32.h"
 #include <string.h>
+#include <stddef.h>
 
 static const char *TAG = "wl_flash";
 #ifndef WL_CFG_CRC_CONST
@@ -143,7 +145,7 @@ esp_err_t WL_Flash::init()
              this->state.pos,
              this->state.move_count);
 
-    ESP_LOGD(TAG, "%s starts: crc1=%i, crc2 = %i, this->state.crc=%i, state_copy->crc=%i, version=%i, read_version=%i", __func__, crc1, crc2, this->state.crc, state_copy->crc, this->cfg.version, this->state.version);
+    ESP_LOGD(TAG, "%s starts: crc1= 0x%08x, crc2 = 0x%08x, this->state.crc= 0x%08x, state_copy->crc= 0x%08x, version=%i, read_version=%i", __func__, crc1, crc2, this->state.crc, state_copy->crc, this->cfg.version, this->state.version);
     if ((crc1 == this->state.crc) && (crc2 == state_copy->crc)) {
         // The state is OK. Check the ID
         if (this->state.version != this->cfg.version) {
@@ -158,7 +160,7 @@ esp_err_t WL_Flash::init()
                 result = this->flash_drv->write(this->addr_state2, &this->state, sizeof(wl_state_t));
                 WL_RESULT_CHECK(result);
                 for (size_t i = 0; i < ((this->cfg.full_mem_size / this->cfg.sector_size)*this->cfg.wr_size); i++) {
-                    bool pos_bits = 0;
+                    bool pos_bits;
                     result = this->flash_drv->read(this->addr_state1 + sizeof(wl_state_t) + i * this->cfg.wr_size, this->temp_buff, this->cfg.wr_size);
                     WL_RESULT_CHECK(result);
                     pos_bits = this->OkBuffSet(i);
@@ -169,14 +171,16 @@ esp_err_t WL_Flash::init()
                     }
                 }
             }
-            ESP_LOGD(TAG, "%s: crc1=%i, crc2 = %i, result=%i", __func__, crc1, crc2, result);
+            ESP_LOGD(TAG, "%s: crc1=0x%08x, crc2 = 0x%08x, result= 0x%08x", __func__, crc1, crc2, (uint32_t)result);
             result = this->recoverPos();
             WL_RESULT_CHECK(result);
         }
     } else if ((crc1 != this->state.crc) && (crc2 != state_copy->crc)) { // This is just new flash or new version
         // Check if this is new version or just new instance of WL
+        ESP_LOGD(TAG, "%s: try to update version - crc1= 0x%08x, crc2 = 0x%08x, result= 0x%08x", __func__, (uint32_t)crc1, (uint32_t)crc2, (uint32_t)result);
         result = this->updateVersion();
         if (result == ESP_FAIL) {
+            ESP_LOGD(TAG, "%s: init flash sections", __func__);
             result = this->initSections();
             WL_RESULT_CHECK(result);
         }
@@ -190,7 +194,7 @@ esp_err_t WL_Flash::init()
             result = this->flash_drv->write(this->addr_state2, &this->state, sizeof(wl_state_t));
             WL_RESULT_CHECK(result);
             for (size_t i = 0; i < ((this->cfg.full_mem_size / this->cfg.sector_size) * this->cfg.wr_size); i++) {
-                bool pos_bits = 0;
+                bool pos_bits;
                 result = this->flash_drv->read(this->addr_state1 + sizeof(wl_state_t) + i * this->cfg.wr_size, this->temp_buff, this->cfg.wr_size);
                 WL_RESULT_CHECK(result);
                 pos_bits = this->OkBuffSet(i);
@@ -207,7 +211,7 @@ esp_err_t WL_Flash::init()
             result = this->flash_drv->write(this->addr_state1, state_copy, sizeof(wl_state_t));
             WL_RESULT_CHECK(result);
             for (size_t i = 0; i < ((this->cfg.full_mem_size / this->cfg.sector_size) * this->cfg.wr_size); i++) {
-                bool pos_bits = 0;
+                bool pos_bits;
                 result = this->flash_drv->read(this->addr_state2 + sizeof(wl_state_t) + i * this->cfg.wr_size, this->temp_buff, this->cfg.wr_size);
 
                 WL_RESULT_CHECK(result);
@@ -230,11 +234,11 @@ esp_err_t WL_Flash::init()
     }
     if (result != ESP_OK) {
         this->initialized = false;
-        ESP_LOGE(TAG, "%s: returned 0x%x", __func__, (uint32_t)result);
+        ESP_LOGE(TAG, "%s: returned 0x%08x", __func__, (uint32_t)result);
         return result;
     }
     this->initialized = true;
-    ESP_LOGD(TAG, "%s - move_count=%08x", __func__, (uint32_t)this->state.move_count);
+    ESP_LOGD(TAG, "%s - move_count= 0x%08x", __func__, (uint32_t)this->state.move_count);
     return ESP_OK;
 }
 
@@ -244,12 +248,12 @@ esp_err_t WL_Flash::recoverPos()
     size_t position = 0;
     ESP_LOGV(TAG, "%s start", __func__); 
     for (size_t i = 0; i < this->state.max_pos; i++) {
-        bool pos_bits = false;
+        bool pos_bits;
         position = i;
         result = this->flash_drv->read(this->addr_state1 + sizeof(wl_state_t) + i * this->cfg.wr_size, this->temp_buff, this->cfg.wr_size);
         pos_bits = this->OkBuffSet(i);
         WL_RESULT_CHECK(result);
-        ESP_LOGV(TAG, "%s - check pos: result=%i, position=%i, pos_bits=0x%08x", __func__, (uint32_t)result, (uint32_t)position, (uint32_t)pos_bits); 
+        ESP_LOGV(TAG, "%s - check pos: result=0x%08x, position= %i, pos_bits= 0x%08x", __func__, (uint32_t)result, (uint32_t)position, (uint32_t)pos_bits); 
         if (pos_bits == false) {
             break; // we have found position
         }
@@ -259,8 +263,8 @@ esp_err_t WL_Flash::recoverPos()
     if (this->state.pos == this->state.max_pos) {
         this->state.pos--;
     }
-    ESP_LOGD(TAG, "%s - this->state.pos=0x%08x, position=0x%08x, result=%08x, max_pos=%08x", __func__, (uint32_t)this->state.pos, (uint32_t)position, (uint32_t)result, (uint32_t)this->state.max_pos);
-    ESP_LOGV(TAG, "%s done", __func__); 
+    ESP_LOGD(TAG, "%s - this->state.pos= 0x%08x, position= 0x%08x, result= 0x%08x, max_pos= 0x%08x", __func__, (uint32_t)this->state.pos, (uint32_t)position, (uint32_t)result, (uint32_t)this->state.max_pos);
+    ESP_LOGV(TAG, "%s done", __func__);
     return result;
 }
 
@@ -277,8 +281,8 @@ esp_err_t WL_Flash::initSections()
     }
     this->state.version = this->cfg.version;
     this->state.block_size = this->cfg.page_size;
-    this->used_bits = 0;
-    this->state.device_id = rand();
+    this->state.device_id = esp_random();
+    memset(this->state.reserved, 0, sizeof(this->state.reserved));
 
     this->state.max_pos = 1 + this->flash_size / this->cfg.page_size;
 
@@ -299,8 +303,8 @@ esp_err_t WL_Flash::initSections()
     result = this->flash_drv->write(this->addr_cfg, &this->cfg, sizeof(wl_config_t));
     WL_RESULT_CHECK(result);
 
-    ESP_LOGD(TAG, "%s - this->state->max_count=%08x, this->state->max_pos=%08x", __func__, this->state.max_count, this->state.max_pos);
-    ESP_LOGD(TAG, "%s - result=%08x", __func__, result);
+    ESP_LOGD(TAG, "%s - this->state->max_count= 0x%08x, this->state->max_pos= 0x%08x", __func__, this->state.max_count, this->state.max_pos);
+    ESP_LOGD(TAG, "%s - result= 0x%08x", __func__, result);
     return result;
 }
 
@@ -309,7 +313,7 @@ esp_err_t WL_Flash::updateVersion()
     esp_err_t result = ESP_OK;
 
     result = this->updateV1_V2();
-    if (ESP_OK == result) return result;
+    if (result == ESP_OK) return result;
     // check next version
     return result;    
 }
@@ -319,7 +323,7 @@ esp_err_t WL_Flash::updateV1_V2()
     esp_err_t result = ESP_OK;
     // Check crc for old version and old version
     ESP_LOGV(TAG, "%s start", __func__);
-    int check_size = offsetof(wl_state_t, crc) - sizeof(uint32_t);
+    int check_size = offsetof(wl_state_t, device_id);
     // Chech CRC and recover state
     uint32_t crc1 = crc32::crc32_le(WL_CFG_CRC_CONST, (uint8_t *)&this->state, check_size);
     // For V1 crc in place of device_id and version
@@ -329,14 +333,14 @@ esp_err_t WL_Flash::updateV1_V2()
 
     if ((crc1 == v1_crc) && (this->state.version == 1)){
         // Here we have to update all internal structures
-        ESP_LOGV(TAG, "%s Update from V1 to V2", __func__);
+        ESP_LOGI(TAG, "%s Update from V1 to V2", __func__);
         uint32_t pos = 0;
 
         for (size_t i = 0; i < this->state.max_pos; i++) {
-            uint8_t pos_bits = 0;
+            uint8_t pos_bits;
             result = this->flash_drv->read(this->addr_state1 + sizeof(wl_state_t) + i * this->cfg.wr_size, &pos_bits, 1);
             WL_RESULT_CHECK(result);
-            ESP_LOGV(TAG, "%s- result=%i, pos=%i, pos_bits=0x%08x", __func__, (uint32_t)result, (uint32_t)pos, (uint32_t)pos_bits); 
+            ESP_LOGV(TAG, "%s- result= 0x%08x, pos= %i, pos_bits= 0x%08x", __func__, (uint32_t)result, (uint32_t)pos, (uint32_t)pos_bits); 
             pos = i;
             if (pos_bits == 0xff) {
                break; // we have found position
@@ -350,7 +354,7 @@ esp_err_t WL_Flash::updateV1_V2()
         this->state.version = 2;
         this->state.pos = 0;
         this->state.crc = crc32::crc32_le(WL_CFG_CRC_CONST, (uint8_t *)&this->state, offsetof(wl_state_t, crc));
-        this->state.device_id = rand();
+        this->state.device_id = esp_random();
 
         result = this->flash_drv->erase_range(this->addr_state1, this->state_size);
         WL_RESULT_CHECK(result);
@@ -358,7 +362,7 @@ esp_err_t WL_Flash::updateV1_V2()
         WL_RESULT_CHECK(result);
 
         memset(this->temp_buff,    0, this->cfg.wr_size);
-        for (int i=0 ; i< pos; i++) {
+        for (uint32_t i=0 ; i<= pos; i++) {
             this->fillOkBuff(i);
             result = this->flash_drv->write(this->addr_state1 + sizeof(wl_state_t) + i * this->cfg.wr_size, this->temp_buff, this->cfg.wr_size);
             WL_RESULT_CHECK(result);
@@ -368,10 +372,10 @@ esp_err_t WL_Flash::updateV1_V2()
         WL_RESULT_CHECK(result);
         result = this->flash_drv->write(this->addr_state2, &this->state, sizeof(wl_state_t));
         WL_RESULT_CHECK(result);
-        ESP_LOGD(TAG, "%s - move_count=%08x, pos=%08x, ", __func__, this->state.move_count, this->state.pos);
+        ESP_LOGD(TAG, "%s - move_count= 0x%08x, pos= 0x%08x", __func__, this->state.move_count, this->state.pos);
 
         memset(this->temp_buff,    0, this->cfg.wr_size);
-        for (int i=0 ; i< pos; i++) {
+        for (uint32_t i=0 ; i<= pos; i++) {
             this->fillOkBuff(i);
             result = this->flash_drv->write(this->addr_state2 + sizeof(wl_state_t) + i * this->cfg.wr_size, this->temp_buff, this->cfg.wr_size);
             WL_RESULT_CHECK(result);
@@ -415,7 +419,7 @@ esp_err_t WL_Flash::updateWL()
     }
     // Here we have to move the block and increase the state
     this->state.access_count = 0;
-    ESP_LOGV(TAG, "%s - access_count=0x%08x, pos=0x%08x", __func__, this->state.access_count, this->state.pos);
+    ESP_LOGV(TAG, "%s - access_count= 0x%08x, pos= 0x%08x", __func__, this->state.access_count, this->state.pos);
     // copy data to dummy block
     size_t data_addr = this->state.pos + 1; // next block, [pos+1] copy to [pos]
     if (data_addr >= this->state.max_pos) {
@@ -425,7 +429,7 @@ esp_err_t WL_Flash::updateWL()
     this->dummy_addr = this->cfg.start_addr + this->state.pos * this->cfg.page_size;
     result = this->flash_drv->erase_range(this->dummy_addr, this->cfg.page_size);
     if (result != ESP_OK) {
-        ESP_LOGE(TAG, "%s - erase wl dummy sector result=%08x", __func__, result);
+        ESP_LOGE(TAG, "%s - erase wl dummy sector result= 0x%08x", __func__, result);
         this->state.access_count = this->state.max_count - 1; // we will update next time
         return result;
     }
@@ -434,13 +438,13 @@ esp_err_t WL_Flash::updateWL()
     for (size_t i = 0; i < copy_count; i++) {
         result = this->flash_drv->read(data_addr + i * this->cfg.temp_buff_size, this->temp_buff, this->cfg.temp_buff_size);
         if (result != ESP_OK) {
-            ESP_LOGE(TAG, "%s - not possible to read buffer, will try next time, result=%08x", __func__, result);
+            ESP_LOGE(TAG, "%s - not possible to read buffer, will try next time, result= 0x%08x", __func__, result);
             this->state.access_count = this->state.max_count - 1; // we will update next time
             return result;
         }
         result = this->flash_drv->write(this->dummy_addr + i * this->cfg.temp_buff_size, this->temp_buff, this->cfg.temp_buff_size);
         if (result != ESP_OK) {
-            ESP_LOGE(TAG, "%s - not possible to write buffer, will try next time, result=%08x", __func__, result);
+            ESP_LOGE(TAG, "%s - not possible to write buffer, will try next time, result= 0x%08x", __func__, result);
             this->state.access_count = this->state.max_count - 1; // we will update next time
             return result;
         }
@@ -453,14 +457,14 @@ esp_err_t WL_Flash::updateWL()
     // write state to mem. We updating only affected bits
     result |= this->flash_drv->write(this->addr_state1 + sizeof(wl_state_t) + byte_pos, this->temp_buff, this->cfg.wr_size);
     if (result != ESP_OK) {
-        ESP_LOGE(TAG, "%s - update position 1 result=%08x", __func__, result);
+        ESP_LOGE(TAG, "%s - update position 1 result= 0x%08x", __func__, result);
         this->state.access_count = this->state.max_count - 1; // we will update next time
         return result;
     }
     this->fillOkBuff(this->state.pos);
     result |= this->flash_drv->write(this->addr_state2 + sizeof(wl_state_t) + byte_pos, this->temp_buff, this->cfg.wr_size);
     if (result != ESP_OK) {
-        ESP_LOGE(TAG, "%s - update position 2 result=%08x", __func__, result);
+        ESP_LOGE(TAG, "%s - update position 2 result= 0x%08x", __func__, result);
         this->state.access_count = this->state.max_count - 1; // we will update next time
         return result;
     }
@@ -484,13 +488,13 @@ esp_err_t WL_Flash::updateWL()
         WL_RESULT_CHECK(result);
         result = this->flash_drv->write(this->addr_state2, &this->state, sizeof(wl_state_t));
         WL_RESULT_CHECK(result);
-        ESP_LOGD(TAG, "%s - move_count=%08x, pos=%08x, ", __func__, this->state.move_count, this->state.pos);
+        ESP_LOGD(TAG, "%s - move_count= 0x%08x, pos= 0x%08x, ", __func__, this->state.move_count, this->state.pos);
     }
     // Save structures to the flash... and check result
     if (result == ESP_OK) {
-        ESP_LOGV(TAG, "%s - result=%08x", __func__, result);
+        ESP_LOGV(TAG, "%s - result= 0x%08x", __func__, result);
     } else {
-        ESP_LOGE(TAG, "%s - result=%08x", __func__, result);
+        ESP_LOGE(TAG, "%s - result= 0x%08x", __func__, result);
     }
     return result;
 }
@@ -503,7 +507,7 @@ size_t WL_Flash::calcAddr(size_t addr)
     } else {
         result += this->cfg.page_size;
     }
-    ESP_LOGV(TAG, "%s - addr=0x%08x -> result=0x%08x, dummy_addr=0x%08x", __func__, (uint32_t) addr, (uint32_t) result, (uint32_t)dummy_addr);
+    ESP_LOGV(TAG, "%s - addr= 0x%08x -> result= 0x%08x, dummy_addr= 0x%08x", __func__, (uint32_t) addr, (uint32_t) result, (uint32_t)dummy_addr);
     return result;
 }
 
@@ -530,7 +534,7 @@ esp_err_t WL_Flash::erase_sector(size_t sector)
     if (!this->initialized) {
         return ESP_ERR_INVALID_STATE;
     }
-    ESP_LOGD(TAG, "%s - sector=0x%08x", __func__, (uint32_t) sector);
+    ESP_LOGD(TAG, "%s - sector= 0x%08x", __func__, (uint32_t) sector);
     result = this->updateWL();
     WL_RESULT_CHECK(result);
     size_t virt_addr = this->calcAddr(sector * this->cfg.sector_size);
@@ -544,14 +548,14 @@ esp_err_t WL_Flash::erase_range(size_t start_address, size_t size)
     if (!this->initialized) {
         return ESP_ERR_INVALID_STATE;
     }
-    ESP_LOGD(TAG, "%s - start_address=0x%08x, size=0x%08x", __func__, (uint32_t) start_address, (uint32_t) size);
+    ESP_LOGD(TAG, "%s - start_address= 0x%08x, size= 0x%08x", __func__, (uint32_t) start_address, (uint32_t) size);
     size_t erase_count = (size + this->cfg.sector_size - 1) / this->cfg.sector_size;
     size_t start_sector = start_address / this->cfg.sector_size;
     for (size_t i = 0; i < erase_count; i++) {
         result = this->erase_sector(start_sector + i);
         WL_RESULT_CHECK(result);
     }
-    ESP_LOGV(TAG, "%s - result=%08x", __func__, result);
+    ESP_LOGV(TAG, "%s - result= 0x%08x", __func__, result);
     return result;
 }
 
@@ -561,7 +565,7 @@ esp_err_t WL_Flash::write(size_t dest_addr, const void *src, size_t size)
     if (!this->initialized) {
         return ESP_ERR_INVALID_STATE;
     }
-    ESP_LOGD(TAG, "%s - dest_addr=0x%08x, size=0x%08x", __func__, (uint32_t) dest_addr, (uint32_t) size);
+    ESP_LOGD(TAG, "%s - dest_addr= 0x%08x, size= 0x%08x", __func__, (uint32_t) dest_addr, (uint32_t) size);
     uint32_t count = (size - 1) / this->cfg.page_size;
     for (size_t i = 0; i < count; i++) {
         size_t virt_addr = this->calcAddr(dest_addr + i * this->cfg.page_size);
@@ -580,11 +584,11 @@ esp_err_t WL_Flash::read(size_t src_addr, void *dest, size_t size)
     if (!this->initialized) {
         return ESP_ERR_INVALID_STATE;
     }
-    ESP_LOGD(TAG, "%s - src_addr=0x%08x, size=0x%08x", __func__, (uint32_t) src_addr, (uint32_t) size);
+    ESP_LOGD(TAG, "%s - src_addr= 0x%08x, size= 0x%08x", __func__, (uint32_t) src_addr, (uint32_t) size);
     uint32_t count = (size - 1) / this->cfg.page_size;
     for (size_t i = 0; i < count; i++) {
         size_t virt_addr = this->calcAddr(src_addr + i * this->cfg.page_size);
-        ESP_LOGV(TAG, "%s - real_addr=0x%08x, size=0x%08x", __func__, (uint32_t) this->cfg.start_addr + virt_addr, (uint32_t) size);
+        ESP_LOGV(TAG, "%s - real_addr= 0x%08x, size= 0x%08x", __func__, (uint32_t) (this->cfg.start_addr + virt_addr), (uint32_t) size);
         result = this->flash_drv->read(this->cfg.start_addr + virt_addr, &((uint8_t *)dest)[i * this->cfg.page_size], this->cfg.page_size);
         WL_RESULT_CHECK(result);
     }
@@ -608,6 +612,6 @@ esp_err_t WL_Flash::flush()
     esp_err_t result = ESP_OK;
     this->state.access_count = this->state.max_count - 1;
     result = this->updateWL();
-    ESP_LOGD(TAG, "%s - result=%08x, move_count=%08x", __func__, result, this->state.move_count);
+    ESP_LOGD(TAG, "%s - result= 0x%08x, move_count= 0x%08x", __func__, result, this->state.move_count);
     return result;
 }
diff --git a/components/wear_levelling/doc/wl_sw_structure.rst b/components/wear_levelling/doc/wl_sw_structure.rst
index d09b86b62..9492140d2 100644
--- a/components/wear_levelling/doc/wl_sw_structure.rst
+++ b/components/wear_levelling/doc/wl_sw_structure.rst
@@ -5,6 +5,11 @@ Wear Levelling Component (WLC) it is a software component that is implemented to
 The WLC do not have internal cache. When write operation is finished, that means that data was really stored to the flash.
 As a parameter the WLC requires the driver to access the flash device. The driver has to implement Flash_Access interface.
 
+The WLC Versioning and Compatibility
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The WLC accept data formats from older version. Latest version of the WLC will update data format from older versions to the current one. 
+Current implementation of WLC has version 2. The data format from current version incompatible with data format from previous versions, and could not be 
+used with previous versions.
 
 The WLC Files
 ^^^^^^^^^^^^^^^
@@ -49,9 +54,9 @@ The wl_config_t contains configuration parameters for the WLC component.
 Internal Memory Organization
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 The WLC divide the memory that are define by start_addr and full_mem_size to three regions:
- - Configuration
  - Data
  - States
+ - Configuration
  
 The Configuration region used to store configuration information. The user can use it to recover the WLC from memory dump.
 The Data - is a region where user data stored. 
diff --git a/components/wear_levelling/private_include/WL_Flash.h b/components/wear_levelling/private_include/WL_Flash.h
index fca72de24..19a682e06 100644
--- a/components/wear_levelling/private_include/WL_Flash.h
+++ b/components/wear_levelling/private_include/WL_Flash.h
@@ -65,7 +65,6 @@ protected:
     uint32_t cfg_size;
     uint8_t *temp_buff = NULL;
     size_t dummy_addr;
-    uint8_t used_bits;
     uint32_t pos_data[4];
 
     esp_err_t initSections();
diff --git a/components/wear_levelling/private_include/WL_State.h b/components/wear_levelling/private_include/WL_State.h
index 7d232d51e..a59de6d7a 100644
--- a/components/wear_levelling/private_include/WL_State.h
+++ b/components/wear_levelling/private_include/WL_State.h
@@ -37,6 +37,7 @@ public:
     uint32_t block_size;    /*!< size of move block*/
     uint32_t version;       /*!< state id used to identify the version of current libary implementaion*/
     uint32_t device_id;     /*!< ID of current WL instance*/
+    uint32_t reserved[7];   /*!< Reserved space for future use*/
     uint32_t crc;           /*!< CRC of structure*/
 } wl_state_t;
 
diff --git a/components/wear_levelling/test/component.mk b/components/wear_levelling/test/component.mk
index ce464a212..47bab9648 100644
--- a/components/wear_levelling/test/component.mk
+++ b/components/wear_levelling/test/component.mk
@@ -1 +1,2 @@
 COMPONENT_ADD_LDFLAGS = -Wl,--whole-archive -l$(COMPONENT_NAME) -Wl,--no-whole-archive
+COMPONENT_EMBED_FILES := test_partition_v1.bin
diff --git a/components/wear_levelling/test/test_partition_v1.bin b/components/wear_levelling/test/test_partition_v1.bin
new file mode 100644
index 000000000..c4b2437d7
Binary files /dev/null and b/components/wear_levelling/test/test_partition_v1.bin differ
diff --git a/components/wear_levelling/test/test_wl.c b/components/wear_levelling/test/test_wl.c
index b875262c0..c8d31bbfb 100644
--- a/components/wear_levelling/test/test_wl.c
+++ b/components/wear_levelling/test/test_wl.c
@@ -31,7 +31,7 @@ TEST_CASE("wl_mount check partition parameters", "[wear_levelling][ignore]")
     size_t size_before, size_after;
     wl_unmount(WL_INVALID_HANDLE);
 
-    esp_partition_erase_range(test_partition, test_partition->address, test_partition->size);
+    esp_partition_erase_range(test_partition, 0, test_partition->size);
     // test small partition: result should be error
     for (int i=0 ; i< 5 ; i++)
     {
@@ -40,7 +40,6 @@ TEST_CASE("wl_mount check partition parameters", "[wear_levelling][ignore]")
         TEST_ESP_ERR(ESP_ERR_INVALID_ARG, wl_mount(&fake_partition, &handle));
         size_after = xPortGetFreeHeapSize();
         TEST_ASSERT_EQUAL_HEX32(size_before, size_after);
-        printf("Test for size 0x%08x passed\n", fake_partition.size);
         // currently this test leaks memory
     }
 
@@ -236,3 +235,54 @@ TEST_CASE("multiple write is correct", "[wear_levelling]")
     free(buff);
     wl_unmount(handle);
 }
+
+extern const uint8_t test_partition_v1_bin_start[] asm("_binary_test_partition_v1_bin_start");
+extern const uint8_t test_partition_v1_bin_end[]   asm("_binary_test_partition_v1_bin_end");
+
+#define COMPARE_START_CONST 0x12340000
+
+// We write to partition prepared image with V1
+// Then we convert image to new version and verifying the data 
+
+TEST_CASE("Version update test", "[wear_levelling]")
+{
+    const esp_partition_t *partition = get_test_data_partition();
+    esp_partition_t fake_partition;
+    memcpy(&fake_partition, partition, sizeof(fake_partition));
+
+    if (partition->encrypted)
+    {
+        printf("Update from V1 to V2 will not work.\n");    
+        return;
+    }
+    fake_partition.size = (size_t)(test_partition_v1_bin_end - test_partition_v1_bin_start);
+
+    printf("Data file size = %i, partition address = 0x%08x, file addr=0x%08x\n", (uint32_t)fake_partition.size, (uint32_t)fake_partition.address, (uint32_t)test_partition_v1_bin_start);
+
+    esp_partition_erase_range(&fake_partition, 0, fake_partition.size);
+
+    esp_partition_write(&fake_partition, 0, test_partition_v1_bin_start,  fake_partition.size);
+
+    wl_handle_t handle;
+    TEST_ESP_OK(wl_mount(&fake_partition, &handle));
+    size_t sector_size = wl_sector_size(handle);
+    uint32_t* buff = (uint32_t*)malloc(sector_size);
+
+    uint32_t init_val = COMPARE_START_CONST;
+    int test_count = fake_partition.size/sector_size - 4;
+
+    for (int m=0 ; m <  test_count; m++) {
+        TEST_ESP_OK(wl_read(handle, sector_size * m, buff, sector_size));
+        for (int i=0 ; i< sector_size/sizeof(uint32_t) ; i++) {
+            uint32_t compare_val = init_val + i +  m*sector_size;
+            if (buff[i] != compare_val)
+            {
+                printf("error compare: 0x%08x != 0x%08x \n", buff[i], compare_val);
+            }
+            TEST_ASSERT_EQUAL( buff[i], compare_val);
+        }
+    }
+
+    free(buff);
+    wl_unmount(handle);
+}
diff --git a/components/wear_levelling/test_wl_host/Makefile b/components/wear_levelling/test_wl_host/Makefile
index eaf5e7b3b..496529ec7 100644
--- a/components/wear_levelling/test_wl_host/Makefile
+++ b/components/wear_levelling/test_wl_host/Makefile
@@ -16,6 +16,7 @@ SPI_FLASH_SIM_LIB := libspi_flash.a
 include Makefile.files
 
 all: test
+	log/esp_random.c \
 
 ifndef SDKCONFIG
 SDKCONFIG_DIR := $(dir $(realpath sdkconfig/sdkconfig.h))
diff --git a/components/wear_levelling/test_wl_host/stubs/log/esp_random.c b/components/wear_levelling/test_wl_host/stubs/log/esp_random.c
new file mode 100644
index 000000000..e664c561f
--- /dev/null
+++ b/components/wear_levelling/test_wl_host/stubs/log/esp_random.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <time.h>
+#include <string.h>
+#include <stddef.h>
+
+#include "esp_system.h"
+
+uint32_t esp_random(void)
+{
+    return (uint32_t)rand();
+}
+
diff --git a/components/wear_levelling/test_wl_host/stubs/log/include/esp_system.h b/components/wear_levelling/test_wl_host/stubs/log/include/esp_system.h
new file mode 100644
index 000000000..74511d5ab
--- /dev/null
+++ b/components/wear_levelling/test_wl_host/stubs/log/include/esp_system.h
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+uint32_t esp_random(void);
+
+#ifdef __cplusplus
+}
+#endif
+
diff --git a/components/wear_levelling/wear_levelling.cpp b/components/wear_levelling/wear_levelling.cpp
index b878ff919..e5e5ffeb8 100644
--- a/components/wear_levelling/wear_levelling.cpp
+++ b/components/wear_levelling/wear_levelling.cpp
@@ -174,7 +174,6 @@ esp_err_t wl_unmount(wl_handle_t handle)
     _lock_acquire(&s_instances_lock);
     result = check_handle(handle, __func__);
     if (result == ESP_OK) {
-        ESP_LOGV(TAG, "deleting handle 0x%08x", handle);
         // We have to flush state of the component
         result = s_instances[handle].instance->flush();
         // We use placement new in wl_mount, so call destructor directly