【ESP32】OTAアップデート機能を実装して、遠隔でファームウェア更新する方法

# Name,   Type, SubType, Offset,  Size, Flags
nvs,      data, nvs,      0x09000,   0x5000,
otadata,  data, ota,      0x0e000,   0x2000,
app0,     app,  ota_0,   0x010000, 0x390000,
spiffs,   data, spiffs,  0x400000, 0xC00000

 ~/dev/clocky/clocky_platformio/.pio/build/upesy_wrover ls -l
drwxr-xr-x  91 ky  staff      2912  3 27 17:03 FrameworkArduino
-rw-r--r--   1 ky  staff     17488  3 27 17:02 bootloader.bin
-rw-r--r--   1 ky  staff   3494720  3 27 17:03 firmware.bin
-rwxr-xr-x@  1 ky  staff  42429048  3 27 17:03 firmware.elf

# Name,   Type, SubType, Offset,  Size, Flags
nvs,      data, nvs,      0x09000, 0x5000,
otadata,  data, ota,      0x0e000, 0x2000,
app0,     app,  ota_0,    0x010000,0x390000,
app1,     app,  ota_1,    0x400000,0x390000,
spiffs,   data, spiffs,   0x790000,0x794000,

-----BEGIN CERTIFICATE-----
MIIDBzCCAe+gAwIBAgIJAO1AEqR+xTGEMA0GCSqGSIb3DQEBCwUAMBQxEjAQBgNV
BAMMCWxvY2FsaG9zdDAeFw0xOTA3MTYxNzMzMTlaFw0yOTA3MTMxNzMzMTlaMBQx
EjAQBgNVBAMMCWxvY2FsaG9zdDCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoC
ggEBAKzXvHhMkYXV/y6Zqj3XJc+iwEDwUWxkRfV8uJFv2oLbXgU8g+Q2DypqJRS6
5tH1dz4sYKAJXJ/80zNn5ddpgga2pF3Fz0IMq7Lq8WxS7OJroFx/UqjXHIepcZtA
4IhVdDfV7o5FyT7C2sFdE7Oe4sRr8n6U9X6eplYdDZHz5FY1+H/wxZtefC5u+zb5
...
-----END CERTIFICATE-----

esp_err_t do_firmware_upgrade()
{
    esp_http_client_config_t config = {
        .url = CONFIG_FIRMWARE_UPGRADE_URL,
        .cert_pem = (char *)server_cert_pem_start,
    };
    // HTTPS OTA設定情報をota_configに格納
    esp_https_ota_config_t ota_config = {
        .http_config = &config,
    };
    // esp_https_ota関数で、FirmwareをOTAアップデート
    esp_err_t ret = esp_https_ota(&ota_config); 
    if (ret == ESP_OK) {
        esp_restart(); // アップデート成功後、デバイスを再起動
    } else {
        return ESP_FAIL;
    }
    return ESP_OK;
}

#include "esp_https_ota.h"
#include "esp_http_client.h"

esp_err_t do_firmware_upgrade()
{
    esp_http_client_config_t config = {
        .url = CONFIG_FIRMWARE_UPGRADE_URL,
        .crt_bundle_attach = esp_crt_bundle_attach, // 証明書バンドルをアタッチ
    };

    esp_https_ota_config_t ota_config = {
        .http_config = &config,
    };

    esp_err_t ret = esp_https_ota(&ota_config);
    if (ret == ESP_OK) {
        esp_restart();
    } else {
        return ESP_FAIL;
    }
    return ESP_OK;
}

[env:myenvironment]
platform = espressif32
board = ...
framework = espidf
; その他の設定
build_flags = 
    -DCONFIG_FIRMWARE_UPGRADE_URL="HTTPSサーバーURL/firmware/firmware.bin"

// ota_update.h#pragma once
#include "esp_err.h"

esp_err_t do_firmware_upgrade();

#include "ota_update.h"
#include "esp_https_ota.h"
#include "esp_http_client.h"

esp_err_t do_firmware_upgrade() {
    esp_http_client_config_t config = {
        .url = CONFIG_FIRMWARE_UPGRADE_URL,
        .crt_bundle_attach = esp_crt_bundle_attach,
    };

    esp_https_ota_config_t ota_config = {
        .http_config = &config,
    };

    esp_err_t ret = esp_https_ota(&ota_config);
    if (ret == ESP_OK) {
        esp_restart();
    } else {
        return ESP_FAIL;
    }
    return ESP_OK;
}

// platform.ini
[env:myenv]
build_flags = -DFIRMWARE_UPGRADE_URL="https://example.com/firmware/firmware.bin

// ota_update.h
#pragma once

void do_firmware_upgrade();

// ota_update.cpp
#include "FS.h"
#include "LittleFS.h"
#include "WiFi.h"
#include "esp_https_ota.h"
#include "nvs_flash.h"
#include "WiFi.h"
#include "esp_tls.h"
#include "esp_err.h"

#ifndef FIRMWARE_UPGRADE_URL
#error "FIRMWARE_UPGRADE_URL is not defined"
#endif
#define CERT_FILE "/root.ca.pem"

esp_err_t _http_event_handler(esp_http_client_event_t *evt)
{
    static char *output_buffer;
    static int output_len;
    static int total_data_len = 0;
    switch (evt->event_id) {
        case HTTP_EVENT_ERROR:
            Serial.println("HTTP_EVENT_ERROR");
            break;
        case HTTP_EVENT_ON_CONNECTED:
            Serial.println("HTTP_EVENT_ON_CONNECTED");
            break;
        case HTTP_EVENT_HEADER_SENT:
            Serial.println("HTTP_EVENT_HEADER_SENT");
            break;
        case HTTP_EVENT_ON_HEADER:
            Serial.printf("HTTP_EVENT_ON_HEADER, key=%s, value=%sn", evt->header_key, evt->header_value);
            break;
        case HTTP_EVENT_ON_DATA:
            Serial.printf("HTTP_EVENT_ON_DATA, len=%dn", evt->data_len);
            total_data_len += evt->data_len;
            break;
        case HTTP_EVENT_ON_FINISH:
            Serial.println("HTTP_EVENT_ON_FINISH");
            break;
        case HTTP_EVENT_DISCONNECTED:{
            Serial.println("HTTP_EVENT_DISCONNECTED");
            break;
        }
        default:
            break;
    }
    return ESP_OK;
}

// ESP32 spiffs内に保存されているルート証明書を呼び出す
String readRootCA() {
    File file = LittleFS.open(CERT_FILE, "r");
    if (!file) {
        Serial.println("Failed to open certificate file");
        return String();
    }
    String cert = file.readString();
    file.close();
    return cert;
}

esp_err_t print_esp_error(esp_err_t err) {
    Serial.printf("esp_error: %sn", esp_err_to_name(err));
    return err;
}

// TODO：nvsからwifi接続情報を呼び出す方法に切り替え検討
void connectWiFi() {
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    Serial.print("Connecting to Wi-Fi");
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000);
        Serial.print(".");
    }
    Serial.println("Connected to Wi-Fi");
}

void do_firmware_upgrade() {
    Serial.println("OTA firmware upgrade start");
    // Wi-Fi接続の確認
    if (WiFi.status() != WL_CONNECTED) {
        Serial.println("Wi-Fi not connected, attempting to connect...");
        connectWiFi();
        if (WiFi.status() != WL_CONNECTED) {
            Serial.println("Failed to connect to Wi-Fi");
            return;
        }
    }

    if (!LittleFS.begin()) {
        Serial.println("Failed to mount file system");
        return;
    }

    // ルートCA証明書を読み込む
    String cert = readRootCA();
    if (cert.length() == 0) {
        return;
    }
    
    // TODO：nvs初期化の必要性があるか？wifi接続などの永続化データ
    esp_err_t err = nvs_flash_init();
    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        esp_err_t erase_err = nvs_flash_erase();
        if (erase_err != ESP_OK) {
            Serial.println("Failed to erase NVS partition");
            return;
        }
        err = nvs_flash_init();
    }
    if (err != ESP_OK) {
        Serial.println("Failed to initialize NVS");
        return;
    }

    Serial.println("Starting OTA task");
    esp_http_client_config_t config = {
        .url = FIRMWARE_UPGRADE_URL,
        .cert_pem = cert.c_str(),
        .event_handler = _http_event_handler,
        .keep_alive_enable = true,
    };
    esp_http_client_handle_t client = esp_http_client_init(&config);
    // 念の為に通信タイムアウトを10分に設定。
    esp_err_t ret = esp_http_client_set_timeout_ms(client, 600000);
    // otaアップデート実施
    esp_err_t result = esp_https_ota(&config);
    if (result == ESP_OK) {
        esp_restart();
    } else {
        Serial.println("Firmware upgrade failed");
        print_esp_error(result);
    }
}

// main.cpp
void loop() {
  static bool isAppMainExecuted = false;
  if (!isAppMainExecuted) {
    do_firmware_upgrade();
    isAppMainExecuted = true;
  }

HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=289
HTTP_EVENT_ON_DATA, len=52
HTTP_EVENT_DISCONNECTED
ets Jul 29 2019 12:21:46

esp_err_t _http_event_handler(esp_http_client_event_t *evt)
{
    static char *output_buffer;
    static int output_len;
    static int total_data_len = 0;
    switch (evt->event_id) {
		    case HTTP_EVENT_DISCONNECTED:{
            Serial.println("HTTP_EVENT_DISCONNECTED");
            Serial.printf( "Total data received before disconnect: %d bytesn", total_data_len);
            int mbedtls_err = 0;
            esp_err_t err = esp_tls_get_and_clear_last_error((esp_tls_error_handle_t)evt->data, &mbedtls_err, NULL);
            if (err != 0) {
                Serial.printf("Last esp error code: 0x%xn", err);
                Serial.printf( "Last mbedtls failure: 0x%xn", mbedtls_err);
            }
            if (output_buffer != NULL) {
                free(output_buffer);
                output_buffer = NULL;
            }
            output_len = 0;
            break;
        }
    }
    return ESP_OK;
}

void do_firmware_upgrade(){
		if (result == ESP_OK) {
        Serial.println("Firmware upgrade succeeded");
        esp_restart();
    } else {
        Serial.println("Firmware upgrade failed");
        print_esp_error(result);
    }
}

HTTP_EVENT_ON_DATA, len=21
HTTP_EVENT_DISCONNECTED
Total data received before disconnect: 3494720 bytes
HTTP_EVENT_DISCONNECTED
Total data received before disconnect: 3494720 bytes
Firmware upgrade succeeded
ets Jul 29 2019 12:21:46

// ip_internal_network/sdkconfig.defaults
CONFIG_LWIP_L2_TO_L3_COPY=y
CONFIG_LWIP_IP_FORWARD=y
CONFIG_LWIP_IPV4_NAPT=y
CONFIG_LWIP_TCP_MSS=624
CONFIG_LWIP_TCP_OVERSIZE_MSS=y
CONFIG_PARTITION_TABLE_CUSTOM=y
CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
CONFIG_PARTITION_TABLE_FILENAME="partitions.csv"
CONFIG_PARTITION_TABLE_OFFSET=0x8000
CONFIG_PARTITION_TABLE_MD5=y

// platform.ini
[env:myenv]
platform = espressif32
board = esp32dev
framework = espidf
build_flags =
    -D CONFIG_LWIP_TCP_MSS=1400

User
In file included from /Users/ky/.platformio/packages/framework-arduinoespressif32/tools/sdk/esp32/include/freertos/include/esp_additions/freertos/FreeRTOSConfig.h:10,
                 from /Users/ky/.platformio/packages/framework-arduinoespressif32/tools/sdk/esp32/include/freertos/include/freertos/FreeRTOS.h:57,
                 from /Users/ky/.platformio/packages/framework-arduinoespressif32/cores/esp32/main.cpp:1:
/Users/ky/.platformio/packages/framework-arduinoespressif32/tools/sdk/esp32/dio_qspi/include/sdkconfig.h:460: warning: "CONFIG_LWIP_TCP_MSS" redefined
 #define CONFIG_LWIP_TCP_MSS 1436

#define CONFIG_LWIP_TCP_MSS 1436