store counter of restarts in NVS (Non-Volatile Storage)

In preparation of #748, this counter will serve as part of an "unique"
token in the log file name ; ensuring that after a reboot we will
not overwrite an existing log file.

The counter is stored in NVS, and is incremented at each class instanciation;
which should roughly translate to every reboot.
(Don't know about the deepsleep for the moment).

The counter will reset to 1 after 99.999.999 restarts, which should gives us
plenty of time.

Signed-off-by: Ludovic LANGE <[email protected]>

vehicle/OVMS.V3/main/ovms_main.cpp

@@ -6,14 +6,14 @@ static const char *TAG = "ovms_main";
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "esp_system.h"
-#include "nvs_flash.h"
 #include <stdio.h>
 #include <string.h>
 #include "ovms.h"
 #include "ovms_peripherals.h"
 #include "ovms_housekeeping.h"
 #include "ovms_events.h"
 #include "ovms_config.h"
+#include "ovms_nvs.h"
 #include "ovms_module.h"
 #include <esp_task_wdt.h>
 
@@ -59,15 +59,17 @@ Peripherals* MyPeripherals = NULL;
 
 void app_main(void)
   {
-  if (nvs_flash_init() == ESP_ERR_NVS_NO_FREE_PAGES)
-    {
-    nvs_flash_erase();
-    nvs_flash_init();
-    }
+
+  // This must be the first call, it initializes the NVS subsystem which is
+  // used by other components - among which the Wifi
+  MyNonVolatileStorage.Init();
 
   ESP_LOGI(TAG, "Executing on CPU core %d",xPortGetCoreID());
   AddTaskToMap(xTaskGetCurrentTaskHandle());
 
+  ESP_LOGI(TAG, "Handling Non-Volatile stored values...");
+  MyNonVolatileStorage.Start();
+
   ESP_LOGI(TAG, "Mounting CONFIG...");
   MyConfig.mount();
 

vehicle/OVMS.V3/main/ovms_nvs.cpp

@@ -0,0 +1,114 @@
+/*
+;    Project:       Open Vehicle Monitor System
+;    Date:          12th November 2022
+;
+;    Changes:
+;    1.0  Initial release - based on public domain code from Espressif (examples)
+;
+;    (C) 2022       Ludovic LANGE
+;
+; Permission is hereby granted, free of charge, to any person obtaining a copy
+; of this software and associated documentation files (the "Software"), to deal
+; in the Software without restriction, including without limitation the rights
+; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+; copies of the Software, and to permit persons to whom the Software is
+; furnished to do so, subject to the following conditions:
+;
+; The above copyright notice and this permission notice shall be included in
+; all copies or substantial portions of the Software.
+;
+; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+; THE SOFTWARE.
+*/
+
+#include "ovms_log.h"
+static const char *TAG = "nvs";
+
+#include "ovms_nvs.h"
+#include "nvs.h"
+#include "nvs_flash.h"
+
+OvmsNonVolatileStorage MyNonVolatileStorage __attribute__ ((init_priority (10000)));
+
+OvmsNonVolatileStorage::OvmsNonVolatileStorage() : m_restart_counter(0){
+  ESP_LOGI(TAG, "Initialising NVS (10000)");
+}
+
+OvmsNonVolatileStorage::~OvmsNonVolatileStorage() {
+  esp_err_t err = nvs_flash_deinit();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Error (%s) de-initialising NVS subsystem!", esp_err_to_name(err));
+  }
+}
+
+void OvmsNonVolatileStorage::Init() {
+  esp_err_t err = nvs_flash_init();
+  if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+    nvs_flash_erase();
+    err = nvs_flash_init();
+  }
+
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Error (%s) initialising NVS subsystem!", esp_err_to_name(err));
+  }
+}
+
+void OvmsNonVolatileStorage::Start() {
+  esp_err_t err = ESP_OK;
+
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
+    nvs_handle_t handle;
+#else
+    nvs_handle handle;
+#endif
+
+  ESP_LOGI(TAG, "Opening Non-Volatile Storage (NVS) default partition and 'ovms' namespace");
+  err = nvs_open("ovms", NVS_READWRITE, &handle);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "Error (%s) opening NVS handle!", esp_err_to_name(err));
+  } else {
+    err = nvs_get_u64(handle, "restart_counter", &m_restart_counter);
+    switch (err) {
+      case ESP_OK:
+        ESP_LOGI(TAG, "Current restart counter: %llu", m_restart_counter);
+        break;
+      case ESP_ERR_NVS_NOT_FOUND:
+        ESP_LOGW(TAG, "The restart counter is not initialized yet");
+        break;
+      default :
+        ESP_LOGE(TAG, "Error (%s) while reading restart counter in NVS!", esp_err_to_name(err));
+    }
+
+    // Write
+    ESP_LOGD(TAG, "Updating restart counter in NVS");
+    m_restart_counter++;
+    // To ease the display on 8 decimal digits, we wrap after 99.999.999 restarts.
+    // If we restart every minute, we'll reach this time in 190 years.
+    if (m_restart_counter > 99999999) {
+      m_restart_counter = 0;
+    }
+    err = nvs_set_u64(handle, "restart_counter", m_restart_counter);
+    if (err != ESP_OK) {
+      ESP_LOGE(TAG, "Error (%s) while updating restart counter in NVS!", esp_err_to_name(err));
+    }
+
+    // Commit written value.
+    // After setting any values, nvs_commit() must be called to ensure changes are written
+    // to flash storage. Implementations may write to storage at other times,
+    // but this is not guaranteed.
+    err = nvs_commit(handle);
+    if (err != ESP_OK) {
+      ESP_LOGE(TAG, "Error (%s) while committing changes in NVS!", esp_err_to_name(err));
+    }
+    nvs_close(handle);
+  }
+}
+
+uint64_t OvmsNonVolatileStorage::GetRestartCount() {
+  return m_restart_counter;
+}

vehicle/OVMS.V3/main/ovms_nvs.h

@@ -0,0 +1,54 @@
+/*
+;    Project:       Open Vehicle Monitor System
+;    Date:          12th November 2022
+;
+;    Changes:
+;    1.0  Initial release - based on public domain code from Espressif (examples)
+;
+;    (C) 2022       Ludovic LANGE
+;
+; Permission is hereby granted, free of charge, to any person obtaining a copy
+; of this software and associated documentation files (the "Software"), to deal
+; in the Software without restriction, including without limitation the rights
+; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+; copies of the Software, and to permit persons to whom the Software is
+; furnished to do so, subject to the following conditions:
+;
+; The above copyright notice and this permission notice shall be included in
+; all copies or substantial portions of the Software.
+;
+; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+; THE SOFTWARE.
+*/
+
+#ifndef __ONVS_H__
+#define __ONVS_H__
+
+#include <stdio.h>
+#include "nvs.h"
+#include "nvs_flash.h"
+#include "esp_idf_version.h"
+
+class OvmsNonVolatileStorage
+  {
+  public:
+    OvmsNonVolatileStorage();
+    ~OvmsNonVolatileStorage();
+
+  public:
+    void Init();
+    void Start();
+    uint64_t GetRestartCount();
+
+  private:
+    uint64_t m_restart_counter;
+  };
+
+extern OvmsNonVolatileStorage MyNonVolatileStorage;
+
+#endif //#ifndef __ONVS_H__