Version 4.2

New Features

• Added a readable message when a device is not detected on a given port (#751)
• image_info: Print flash settings and extended header fields with --version 2 argument
• Added support for 26 MHz XTAL on ESP32-C2
• Expanded minimum revision field to accept higher chip revisions

espefuse.py

• Added XTS_AES_256 key_purpose on ESP32-S3-beta2
• burn_efuse: Improved error messages when a new data value is incorrect (#760)
• get_pkg_version: Fixed on ESP32-C2 (#759)
• Added major and minor wafer version eFuses

Bug Fixes

• load_extended_header: Load the minimum chip revision min_rev field
• Fixed flasher stub on ESP32-H2

espefuse.py

• Removed XTS_AES_256 key purposes on ESP32-C3
• Fixed location of FAIL_BIT and NUM_BITS on ESP32-C3
• Added a warning to specify the --port/-p argument if connection fails (#744)

espsecure.py

• _microecc_format: Pad zeroes to curve length

Miscellaneous Changes

• Clarified USB-OTG-related functions (#756, #757)
• Stub codes are now included as JSON files with metadata for each target

Thanks to @befeleme and others for contributing to this release!

Version 4.1

New Features

• ESP32-C2: Added flash encryption support
• elf2image: Added argument to disable appending SHA256 digests

Bug Fixes

• espsecure.py: Fixed Secure Boot V1 key generation
• espefuse.py: Corrected eFuse tables

Version 4.0.1

Bug Fixes

• Patched the wrapper scripts to not import themselves to allow running esptool, espefuse, and espsecure in different environments and importing these directly in other Python scripts.

Version 4.0

Starting from v4.0.0, esptool adopts the semantic versioning specification, please read the related "Versions" esptool documentation page when deciding which version to use.

Breaking changes

• Public API has been defined by limiting access to internals that have been refactored into multiple source files. Changing or refactoring these limited internals won't be considered a breaking change in future releases. Migration is easy and self-explanatory (you will get an import error if something has moved) and is required only in projects that import esptool directly.
• If active security features are detected, the default behavior changes to prevent unintentional bricking (#699):
  • If flash encryption is enabled, erase_flash and erase_region cannot be executed.
  • If secure boot is enabled, erase_flash, erase_region and write_flash operations cannot be performed (write_flash is just restricted to protect the bootloader region 0x0000->0x8000).
  • An override flag --force lets the users execute these operations anyways.
• Flash parameters in an image header can now be changed only when no SHA256 digest is appended (espressif/esp-idf#8798).
• Python versions 2.7, 3.4, 3.5, and 3.6 have been deprecated, the code is now Python 3-only compatible. Releases v4 and later can't be installed from PyPI on these deprecated Python versions.
• The ESP8684 alias has been removed, ESP32-C2 has to be used.
• Megabit flash sizes have been deprecated, use megabyte units from now on.

New Features

• Added stub flasher support for ESP32-C2 ECO1, deprecated ECO0 stub (can still be used with ROM).

espefuse.py

• Added a new package - ESP32-D0WDR2-V3

Bug Fixes

• Fixed ESP32-S3 USB-OTG compressed flashing
• Fixed division by zero error when reading flash (#729)

Miscellaneous Changes

• Black code formatting has been adopted in the esptool project. Contributions will be automatically formatted in a compatible way when following the contributions guide.

Thanks to everyone who contributed to this release.

Version 3.3.1

New Features

• Added stub flasher support for ESP32-C2 ECO1, deprecated ECO0 stub (can still be used with ROM)

espefuse.py

• Added a new package - ESP32-D0WDR2-V3

Bug Fixes

• Fixed ESP32-S3 USB-OTG compressed flashing

Version 3.3

New Features

• Added flash size options up to 128MB. (#680)
• Added stub flasher support for ESP32-C2.
• Added --flash-mmu-page-size option to change flash MMU page size on ESP32-C2.
• Added address and dummy cycles configuration to SPI flash commands, allowed reading flash SFDP registers.
• Added target-specific flash frequency options.

espsecure.py

• Added support for ECDSA P192 and P256 signatures in Secure Boot V2.
• Refined Secure Boot V2 ECC support.
• Added support for XTS_AES_128 using 128 bit key FE scheme.

espefuse.py

• Added execute_scripts nesting support, a script can now be called from another script.
• Added ESP32-C2 espefuse.py support.
• Fixed power-out time for VDDQ settings for ESP32-S3.
• Removed dysfunctional JTAG_SEL_ENABLE on ESP32-C3.
• Removed unused eFuse fields on ESP32-C3 and ESP32-H2.
• Added execute_scripts error handling in script files. (espressif/esp-idf#8420)
• Added support for running multiple commands at once.
• Added checks for secure download mode.
• Added a recovery option to fix eFuse blocks after encoding errors.

Internal features

These features are intended for use inside Espressif:

• Preview support for ESP32-H2-beta2 has been added. This SoC is not generally available, so it is unsupported in this release. Official support will be added in a later esptool.py release.

Bug Fixes

• Fixed autodetection on ESP32-S2 in USB-OTG mode. (#685)
• Fixed flash.rodata not being recognized as part of IRAM in the ELF parser.
• Fixed wrong UART_RXFIFO_CNT_M mask values in the stub flasher.
• Added overerase detection and a fix sequence for certain XMC flash chips.
• Allowed USB PID detection for USB-JTAG-Serial mode on lowercase port names.
• Fixed chip autodetection to work in secure download mode.
• Fixed wrong firmware image being returned for beta chips.
• Fixed a wrong bootloader flashing offset on ESP32-S3. (#728)

Miscellaneous Changes

• Launched a new self-hosted esptool.py documentation and heavily updated its contents.
• Renamed the ESP8684 target to ESP32-C2 (added alias for compatibility).
• Added a warning for flash sizes that are not supported by the stub flasher.

Thanks to @ESP32DE, @lucasrangit, @Jason2866, and others for contributing to this release.

Version 3.2

New Features

• Support for ESP32-S3 SoC has been added (removed ESP32-S3-beta3).
• Added USB-JTAG-Serial and USB-CDC support for ESP32-S3.
• Added a check to disable stub when connecting to an unsupported chip.
• Added boot log detection and context of failures logging.
• Improved error messages to cover more cases and provide more information.
• Added get_security_info command stub support.
• Augmented chip autodetection to work even in secure download mode. (ESP32-C3 and later only)
• Added flash chip connection verification check.
• Added ESP8266 version 3 image format support.

espsecure.py

• Added option for 512bit keys for encrypt_flash_data.

espefuse.py

• Added a new command which can execute custom python scripts to burn efuses all at once.
• Added ESP32-S2 flash_ver, psram_ver, and pkg_ver efuses.
• Corrected lenght of soft_dis_jtag efuse.
• Added custom_mac eFuse field for ESP32-C3/-S2/-S3/-H2.
• Added a check for read_protect_efuse. (#640)
• Added support for 512bit XTS_AES flash encryption key.
• Added a step to close the serial port after espefuse operations. (#671)
• Added a security confirmation flag to espefuse tests. (#677)

Internal features

These features are intended for use inside Espressif:

• Preview support for ESP32-H2 and ESP8684 has been added. These SoCs are not generally available, so they are unsupported in this release. Official support will be added in a later esptool release.
• Added automatic delay for boot time after ESP32 reset in FPGA.

Bug Fixes

• Fixed build from sources (require wheel only when installing from pip). (#632)
• Fixed failing flashing process on some supported chips. (#635)
• Fixed ESP32-C3 package detection. (#638, #639)
• Fixed test child processes being blocked waiting for the OS pipe buffer to accept more data. (#637)
• Fixed MacOS USB PID detection on tty and cu ports.
• Fixed erroneous comparison when handling deflated data. (#650)

Miscellaneous Changes

• Changed unnecessarily alarming error to a warning. (#631)
• Removed ESP32 rev0 connection workaround.
• Added a readable error and a use example to merge_bin.

Thanks to @bbilas, @xingrz, @loader-bsd, @alvarolb, and others for contributing to this release.

Version 3.1

New Features

• Support for ESP32-C3 SoC has been added
• Added --encrypt-files option to specify which files need encryption before flashing.
• Added --use_segments option for elf2image to use segments instead of sections to generate the image. (#546)
• Improved the write_flash timeout calculation and status message.
• Support for detecting ESP8285 versions -N08, -N16, -H08, and -H16 has been added.
• Added support for all write_reg command forms (including delay and mask parameters) to flasher stub.
• Added merge_bin command to combine binary files on host (#254, #568)
• Extended the --min-rev argument of elf2image to work on all chips apart from ESP8266.
• Added diagnostic warnings about the memory regions needing to be erased during a flash write (#306)
• Added --after no_reset_stub option to keep the flasher stub running and allow its repeated usage.
• Added support for the USB-JTAG-Serial peripheral of ESP32-C3.

espsecure.py

• Added custom command-line argument to allow calling from other Python scripts.
• Added --aes-xts option to encrypt/decrypt flash data files with AES-XTS algorithm on the S2 and C3.
• Fixed handling of files to forbid empty output and re-writing input.

espefuse.py

• Added custom command-line argument to allow calling from other Python scripts.
• Added security measures to prevent burning custom multicast MAC address. (#472)
• Fixed errors when burning and read-protecting an efuse at the same time (#584)
• Fixed burning of SPI pins configuration efuses (#216)

Internal features

These features are intended for use inside Espressif:

• Support for ESP32-S3-beta3 & ESP32-C6-beta have been added. These SoCs are not generally available, so they are unsupported in this release. Official support will be added in a later esptool release.
• Support for 32-bit addressing to enable 32/64MB flash memory chips on the S3.

Bug Fixes

• Fixed error outputs when installing from pip.
• Increased the timeout for writing to flash to improve stability (#577, #533)
• Fixed failing dump_mem overall bytes read message.
• Allowed the write_mem mask argument to be optional to match with its usage example on Wiki.
• Ensured expand_file_arguments gets called when using custom command-line arguments. (#400)
• Fixed SecureBoot v2 public key extraction (#623)

Miscellaneous Changes

• Decomposed port detection logic.
• Added flushing after each command before waiting for a reply.
• Made it easier to use esptool.py as a component by permitting passing an already formed esp object to main() (#402)
• Added function to merge adjacent sections in elf2image for the use case of linker scripts that have a large number of sections.
• Decoupled esptool reset logic for easier monkey-patching (#508)

Thanks to @Skallwar, @eykamp, @gnought, @middelink and others for contributing to this release.

Version 3.0

Breaking changes

• The default esptool.py write_flash --flash_size argument has changed from detect to keep. This means that if no --flash_size argument is passed when flashing a bootloader, the value in the bootloader .bin file header is kept instead of detecting the actual flash size and updating the header. To keep the old behaviour, add the argument esptool.py [...] write_flash [...] -fs detect
• espefuse.py command line arguments for ESP32 have changed:
  • BLK1, BLK2, BLK3 is now BLOCK1, BLOCK2, BLOCK3`
  • The key usage secure_boot has been replaced with secure_boot_v1, secure_boot_v2. Secure Boot V2 is the new RSA-based Secure Boot mechanism supported on ESP32 V3.

New Features

• Support for ESP32-S2 SoC has been added
• Support for detecting ESP32-PICO-V3-02 and ESP32-U4WDH have been added
• New --connect-attempts argument (#464)
• Fixed scrolling problems when output is redirected (for example in Arduino IDE, see discussion at #482)
• Produce a meaningful error if the SoC we connect to doesn't match the --chip argument
• Support different capitalization and spelling for --chip argument (ie -c ESP32, -c esp32-s2, etc.
• Added dedicated program esp_rfc_2217_server.py for flashing via RFC2217 (i.e. flashing over the network, #383)

espsecure.py

• Added support for Secure Boot V2 (ESP32 V3, ESP32-S2)
• Secure Boot V1: PKCS8 formatted ECDSA keys are now supported via ecdsa library (not including password protected keys)

espefuse.py

• Added ESP32 ECO3 efuse UART_DOWNLOAD_DIS
• Added new batch burn mode, support burning more than one eFuse on a single command line
• espefuse.py internals have been refactored to support multiple chips, produce more information about which eFuses are being written to which values.
• "Virtual" mode added for host-based testing, allows updating eFuse values on a "virtual" chip inside the host.

Internal features

These features are intended for use inside Espressif:

• Support for ESP32-S3beta2 & ESP32-C3 have been added. These SoCs are not currently available outside Espressif, so these SoCs are unsupported in this release. Official support will be added in a later esptool release.
• esptool.py --no-stub read_flash is now supported on ESP32 and later. This option is slower than using the default stub option to read flash, so it's generally not useful for production SoCs.

Bug Fixes

• Added temporary workaround for a pyserial failure on macOS Big Sur Preview (#540)
• Fixed gcc9 warning in the stub (#501)
• Fixed some memory types printed in the memory map output
• Fixed the check for zero bytes before applying an ELF SHA-256 with elf2image --elf-sha256-offset option (#560)
• Fixed displaying some single core ESP32 features incorrectly, i.e. ESP32-S0WD
• Fixed exception on Python 3 if the same flash address was repeated twice (#558)

Miscellanous Changes

• Updated miniz to v2.1.0 (#500)
• Moved ESP32 stub loader location to facilitate loading large applications direct to IRAM
• Vendored modules ecdsa, pyaes and optional pycrypto have been removed. Pyaes has been replaced with the pyca-cryptography library

Thanks to @jkoelker, @earlephilhower, @paravoid, @niziak, and others for contributing to this release.

Version 2.8

Features

• esptool.py image_info now prints a summary of segment memory types (IRAM, DRAM, etc) based on the address range.
• esptool.py write_flash will warn if it looks like a bootloader binary is built for ESP32-S2 or another newer chip (support for flashing ESP32-S2 will be added in a future version.)

Bug Fixes

• Removed ESP8266 SDK & ESP-IDF dependencies when building the flasher stub binaries. Previously the SDKs were used to include some register address macros, only. This removes any uncertainty about whether the flasher stub binary is a derived work of either SDK. The flasher stub binary itself is the same as the binary in v2.7.
• Fixed minor issues running esptool automated tests on macOS.
• Minor flake8 fixes including compatibility with newer flake8 versions.

ESP32 Only

Features

• Support detection of new ESP32 silicon revisions
• New esptool.py elf2image --min-rev X option allows creating a .bin file which only supports a minimum ESP32 silicon revision.

Bugfixes

• Fix burning custom MAC with espefuse.py when 3/4 Coding Scheme is set (#447)