# System

[English]

## Time

- `ESP32-S2/rtc.h` is deprecated, include the replacement `esp_rtc_time.h` instead.

## Log

Log V2 is introduced in this ESP-IDF version as an enhanced and optional logging implementation. It is fully compatible with Log V1, allowing projects to continue using Log V1 without changes. Developers can enable Log V2 via the Kconfig option CONFIG_LOG_VERSION. In future ESP-IDF versions, Log V2 may become the default.

Key Points

- Centralized log handling, dynamic formatting, and greater flexibility.

- Slightly higher stack and IRAM usage, with a reduced binary size (refer to measurements in the Logging Library document).

- Log V2-specific features (e.g., dynamic formatting, detecting the execution context) are not backward-compatible with Log V1.

If you use the `esp_log_write` (or `esp_log_writev`) function, replace it with `esp_log` (or `esp_log_va`) to reduce one nested call.

The log handler (`esp_log`) supports internal formatting, so there is no need to construct formatting manually. The code below can be simplified by using `ESP_LOG_LEVEL_LOCAL`.

    #if ESP_LOG_VERSION == 2
        ESP_LOG_LEVEL_LOCAL(ESP_LOG_ERROR, OT_PLAT_LOG_TAG, format, args);
    #else
        if (LOG_LOCAL_LEVEL >= ESP_LOG_ERROR) {
            esp_log(ESP_LOG_CONFIG_INIT(ESP_LOG_ERROR), OT_PLAT_LOG_TAG, LOG_COLOR_E "E(%lu) %s:", esp_log_timestamp(), OT_PLAT_LOG_TAG);
            esp_log_va(ESP_LOG_CONFIG_INIT(ESP_LOG_ERROR), OT_PLAT_LOG_TAG, format, args);
            esp_log(ESP_LOG_CONFIG_INIT(ESP_LOG_ERROR), OT_PLAT_LOG_TAG, LOG_RESET_COLOR "\n");
        }
    #endif

## Pre-Encrypted OTA

The `pre_encrypted_ota` example has been moved to the idf-extra-components repository.

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