Release Version 4.0 · espressif/esptool

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.

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

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.