ESP-IDF Pre-release v4.1-beta1

Documentation for pre-release v4.1-beta1 is available at https://docs.espressif.com/projects/esp-idf/en/v4.1-beta1/

ESP-IDF v4.1 is a minor update for ESP-IDF v4.0.

This is the list of changes since release v4.0:

Major New Features

Preview support for ESP32-S2 Beta SoC. This support will be replaced with ESP32-S2 SoC support in ESP-IDF v4.2. ESP32-S2 Beta firmware is not compatible with the ESP32-S2 production SoC.
New Python-based menuconfig tool
Networking: Added new esp_netif API to manage network interfaces, replaces tcpip_adapter which is now deprecated.
Classic Bluetooth: Added support for Hands Free Profile (HFP) Audio Gateway (AG)
DTLS support in libcoap using mbedTLS (#3977)

Bluetooth

Controller

Improved handling of calloc() failure
Fixed HCI timeout issues when using multiple cores and sleep is enabled
Fixed BLE crash issue triggered by BLE event interrupt missed
Fixed bugs related to role switch
Fall back to main XTAL as Bluetooth sleep clock source if the External 32kHz crystal is configured but not detected
Fixed a division by zero error in BT sleep clock cycle calculation
Fixed software assertion of invalid state when using HCI_Create_Connection_Cancel command

Bluedroid

Fixed bug with fixed_queue semaphore pointer dereference
Fixed potential memcpy buffer overflow problem
Fixed wrong complete Identity Address (Public Address) of the Privacy-enabled Bonded Device got after bonding
Fixed the issue with pointer type conversion in gattc
Added missing GATT descriptors 0x2909 (Number of Digitals) through 0x290E (Time Trigger Setting) (#4082, #4470)

NimBLE

Updated to latest 1.2.0 upstream NimBLE release
Added config option to enable host flow control
Added support to use dynamic buffers instead of static memory
Added new project configuration options for host task stack size
Added system level mbuf block count (MSYS_1) option in project configuration
Fixed check for static random address in ble_hs_id_set_rnd()
Increased maximum concurrent connections to 9

Classic Bluetooth

Added new esp_bt_gap_read_remote_name() function to get remote device's Bluetooth name at any time
Fixed error on EIR type in Config EIR event
Added support to enable Peripheral Preferred Parameters in GAP service
HFP: Added Audio Gateway (AG) support
HFP: Added AT+NREC=0 command for disabling AG echo cancellation (#3665)
HFP: Fixed crash on incoming audio
HFP: Fixed connection fail and crash when receiving unknown AT command

Blufi

Fixed the wrong type from BLUFI_TYPE_DATA_SUBTYPE_SOFTAP_MAX_CONN_NUM to BLUFI_TYPE_DATA_SUBTYPE_SOFTAP_CHANNEL

BLE Mesh

Synchronized Zephyr v2.0 BLE Mesh updates
Updated mesh examples and added example description
Fixed getting wrong timer remaining time
Added advertising buffers for relay packets
Modified Health Server model callbacks
Added Heartbeat message receive callback
Added low power node APIs and events
Added friend node events
Added proxy client functionality
Added sig-defined server models
Added Configuration Server model events
Checked mesh queue and task init status
Fixed client model invalid address access
Fixed not restoring mesh node cfg value
Now uses bt device name in mesh proxy adv
Fixed mesh device with wrong name on iOS
Checked client model timer remaining time
Fixed memory leak when node is reset
Fied adv buf unref and link_id in exceptional list

Wi-Fi Coexistence

Fixed A2DP disconnect when Wi-Fi switches channels
Fixed A2DP stuck after creating another connection

Wi-Fi

Added PMK caching feature for WPA2 Enterprise stations
Added support for Protected Management Frames (PMF)
Added SAE authentication support for WPA3 Personal
Wi-Fi now uses new esp_event library added in ESP-IDF v4.0
Fixed wpa_supplicant EAP re-authentication issue
Fixed wpa_supplicant assoc_ie_len setting based on generated RSN/WPA IE
Fixed EAPOL key used during reauthentication
Fixed wpa_supplicant memory leak on Wi-Fi stop
Fixed ESP-NOW unicast packet TX failure
Fixed bug for setting channel when in NULL mode.
Added check for Wi-Fi stop when calling esp_wifi_deinit
Now places the Vendor Specific element at the end according to the protocol
Fixed crash during WEP shared auth
Fixed WiFi buffer reload that WiFi receiving no longer works because internal buffer reloading fails
Fixed WiFi receiving that WiFi receiving no longer works because it writes the MAC registers when WiFi/BT common clock is disabled
Fixed WiFi performance, including AMPDU parameter negotiations, WiFi TX optimization etc
Fixed AMSDU decrypt that ESP32 can't decrypt the AMSDU if it's encrypted
Reduced Wi-Fi compiled binary size
Added TX packet length checking, Wi-Fi driver will drop a packet which is too long
Improved RSSI scan accuracy
Now returns an error if the setting AP's channel is out of range
Fixed sniffer during WiFi mode switching

Ethernet

Fixed Ethernet interrupt crash when cache is disabled
Ensure that eth_driver handle is allocated in internal RAM (#4635)

Peripheral Drivers

Most drivers have been refactored internally, however public behaviour of existing APIs should be the same as in ESP-IDF V4.0
Added option to place UART ISR in IRAM
Added new ESP Serial Slave Link library to communicate with serial slave devices via SDIO or similar interfaces
CAN: Fixed can_reconfigure_alerts() function taking semaphore in a critical section
CAN: Fixed possible logging in critical sections
CAN: Added bitfields to can_message_t as an alternate way to set CAN message flags.
I2S: Fixed compile error if FreeRTOS header not included before I2S header (#4251)
LEDC: Added missing ledc_set_pin() function declaration
SDSPI & SDMMC: Fixed gpio_pin_bit_mask truncation to max GPIO value 31
UART: Added simplified API to set threshold values for RX FIFO full and TX FIFO empty
SPI_SLAVE: Fixed assertion failure when spi_slave_initialize failed with DMA channel equals zero (#2740)

Core System

Fixed DPORT ECO workaround register operation to improve workaround reliability. (Details of workaround in ECO document item 3.10 "When each CPU reads certain different address spaces simultaneously, a read error can occur")
Added a macro to call a function with a user-allocated stack
Added likely & unlikely macros to help compiler produce optimized instruction sequences
bootloader_random: Added protected for shared CLK_EN & RST_EN registers when calling bootloader_random_enable()/_disable() in the app
esp_attr: Fixed multiple definition linker errors when using section attributes in C++ builds (#4021 )
esp_event: Fix a possible null pointer dereference (#4373)
esp_timer: Add parameter NULL checks to public API Return ESP_ERR_INVALID_ARG if the handle is NULL, instead of crashing.
heap: Added dedicated "aligned alloc" and "aligned free" functions functions (some restrictions apply, see linked documentation).
heap: Added new heap_caps_get_allocated_size() functionv
ipc: IPC now runs at priority of the caller's task, preventing priority inversion issue where one core commandeers the other core
log: Added option to log system time rather than RTOS time (#3958)
mac: Calling esp_base_mac_addr_set() now fails if MAC is not a unicast MAC (#4263)
panic handler: Moved some panic handler code into flash to reduce IRAM usage, cache will be re-enabled in panic handler if necessary
pthread: Fixed pthread_once() possible race condition (#4561)
single core: Don't compile in unnecessary ipc code in single core configurations
startup: Clear RF PHY peripheral status during early startup
time: Added optional support for 64-bit time_t, depends on toolchain support which is not part of the default toolchain yet, this is planned for ESP-IDF v5.0.
toolchain: add new compiler optimization levels for "Performance" (-O2) and "None" (-O0)

FreeRTOS

Reduced interrupt cycle overhead by using window overflow and underflow exceptions to speed up Xtensa register spills to the stack
Added support for including FreeRTOS headers using the traditional header paths, instead of requiring freertos/ prefix

newlib libc

Fixed linking of newlib nano from ROM only if PSRAM cache workaround is disabled

LWIP

Added option to automatically resolve mDNS queries when looking up .local addresses
Added IPV6 stateless address autoconfiguration support
Cleaned up the TCP/IP stack port layer
Fixed crash when a netconn is marked as closed
Fix select_waiting() assert caused by UDP socket closing
Fix the crash caused by socket lock not initialized
Fixed issue with IPV6 TCP sending OK when STA disconnects
MLD6: Fixed error when attempting to join a non-multicast IPV6 address
Now includes hostname in DHCP discover packet, if set
PPPoS: Fixed power_down DCE immediately after getting IP
sntp: Added API to set the SNTP update interval (#4437)

mDNS

Added configuration values for mDNS task priority, affinity, internal service timeouts
Fixed missing "bye" packet if services removed with mdns_service_remove_all() or mdns_free() (#3660)

Provisioning

NimBLE: Fix bug in protocomm_nimble chararcteristic access callback
Unified Provisioning: Fixed BLE characteristics read response issue when read response length is a multiple of () length
Wifi_provisioning_softap: Allow applications to start webserver externally
Wifi_prov_manager: Fix to ensure that provisioning status is reliably conveyed to remote host

OTA

esp_https_ota: Added error checking functionalities. A few additional error checking mechanisms have been added which returns the control in case an invalid header is received, and a wrapper to the esp_http_client_is_complete_data_received() function of esp_http_client has been added.

HTTP Client

Added esp_http_client_set_authtype() function (#4444)
Fixed HTTP client issue regarding message_complete callback invocation (fixes some issues with OTA failing with unexpected errors if the connection closes early)
Fixed memory leak in esp_http_client_set_username/password (#4444)

mbedTLS

Added new fast Montgomery exponentiation implementation for RSA accelerator. Significantly improves ESP32 RSA performance (especially public key operations)
Don't allow disabling ECDSA support in mbedTLS config if app image signature checking is enabled

ULP

Added some missing ULP macro functionality: stage counters, branch on stage counter, I2C operations. (#3580)
Added ULP macro MOVE <label> construct which helps when writing larger programs. (#3580)
Added a union member to allow getting the encoded ULP instruction from a macro result (#3759)

Bootloader

Added option to skip image validation when waking from deep sleep (incompatible with Secure Boot) (#3304)
Restructured bootloader initialization, moving target-specific initialization into separate source files

ESP-TLS

Added support for WolfSSL backend (see https://github.com/espressif/esp-wolfssl)
Added timeout support for blocking connections

TCP Transport

Added API to use password protected client keys
Added functionality to use ALPN with SSL

Websocket

Added User-Agent and additional headers to websocket client (#4345)

Storage

FATFS: handle the internal FR_INT_ERR error as "filesystem corrupted"
NVS: Add support to expose a NVS entry via a C++ smart pointer handle
SPIFFS: Fixed bugs when CONFIG_SPIFFS_USE_MTIME is not defined
SPIFFS: Now follows symlinks in spiffsgen (#3778)
spi_flash: Added new SPI flash driver using new hardware abstraction layer (backwards compatible API, legacy implementation can be re-enabled)

VFS

VFS: Check in select() if the UART driver is installed or not

Modbus

Added support for Modbus ASCII master mode
Fixed issue re-initializing Modbus controller after call to mbc_master_destroy()

External Libraries

coap: Improved support for different mbedTLS configurations (#3961, #3971, #3977)
jsmn: Added project configuration options for library (#4416)
tinycbor: Added new tinycbor component and example

Tools

c++: Allow enabling RTTI
core dump: Default Core Dump data format is now ELF (configurable)
idf_monitor: Work around a Windows driver bug when using a USB-CDC device
idf_monitor: fix the bug that idf_monitor not blocked when no log printed (#3884)
idf_size: Added support to write size data to a JSON file
idf_size: Significantly improved performance (#4518)
openocd: Documented support for ARM architecture

Build System

Added PowerShell versions of "install.bat" and "export.bat" for Windows PowerShell users
Added idf.py --cache option and support for setting config variable IDF_ENABLE_CCACHE to permanently enable CCache
Added minor fixes for convert_to_cmake.py
Added new idf.py --version command
Allow idf.py and CMake build system to work on FreeBSD (not officially supported) (#2029)
Fix IDF_PATH case mismatches on case insensitive filesystems
Fixed execution order for dependent tasks
Updated kconfiglib to the upstream version, switch to a Python-based menuconfig tool

Examples

http_request: Fixed some non-compliant parts of the HTTP request, amde example configurable
Improved the example behaviour when esp_restart() is called and Wi-Fi is initialized
ping: Added new example
restful server: Added NetBIOS support for discovery
tcp_server: Fixed unnnecessary reopening of listening socket
efuse: Added example demonstrating efuse API for writing efuses
ble throughput: Fixed intermittent crash when running the BLE throughput client
ble hid device: Fixed the wrong mask value based on the HID protocol
ble hid device: Fixed issue with security info restore when a paired BLE HID device disconnects and then reconnects after a BT Classic HID device has connected
blufi: Changed the Wi-Fi storage mode to default WIFI_STORAGE_FLASH
bluetooth: Added HFP Audio Gateway example
ota: Fixed bug with failing OTA if the connection closed prematurely

Documentation

Translated more ESP-IDF Programming Guide pages into Chinese
Added basic C++ style guide
Encourage Python 3 rather than Python 2 for new users
Added Getting Started Guide for Ethernet Kit V1.1

Obtaining v4.1-beta1

For full installation instructions, see the ESP-IDF Programming Guide.

The source files attached to this release will not work due to our use of git submodules. Use one of the following methods instead:

Using git

To get this release, use the following commands:

git clone -b v4.1-beta1 --recursive https://github.com/espressif/esp-idf.git esp-idf-v4.1-beta1
cd esp-idf-v4.1-beta1/

This is the recommended way of obtaining v4.1-beta1 of ESP-IDF.

Download an archive with submodules included

Attached to this release is an esp-idf-v4.1-beta1.zip archive. It includes .git directory and all the submodules, so can be used out of the box. This archive is provided for users who have connectivity issues preventing them from cloning from GitHub.

This archive can also be downloaded from Espressif's download server:
https://dl.espressif.com/dl/esp-idf/releases/esp-idf-v4.1-beta1.zip