esp_cache_msync() function

Memory sync between Cache and storage memory For cache-to-memory (C2M) direction: - For cache writeback supported chips (you can refer to SOC_CACHE_WRITEBACK_SUPPORTED in soc_caps.h) - This API will do a writeback to synchronise between cache and storage memory - With ESP_CACHE_MSYNC_FLAG_INVALIDATE, this API will also invalidate the values that just written - Note: although ESP32 is with PSRAM, but cache writeback isn't supported, so this API will do nothing on ESP32 - For other chips, this API will do nothing. The out-of-sync should be already dealt by the SDK For memory-to-cache (M2C) direction: - This API will by default do an invalidation This API is cache-safe and thread-safe