feat(arduino): Add support for fast flashing with esptool

[lucasssvaz]

Description

This pull request introduces a robust "fast-flash" mechanism for Arduino-based ESP devices, enabling incremental reflashing using esptool's --diff-with feature. This approach speeds up firmware updates by flashing only changed regions and maintaining per-binary reference files. The implementation includes changes to flash argument parsing, flashing logic, reference management, and comprehensive tests to ensure correctness and reliability.

Fast-flash and flashing logic improvements:

• Refactored the parsing of the flash_args file in ArduinoApp to extract both flash settings and a list of (address, filepath) pairs, enabling individual binary flashing instead of using a merged binary. (pytest_embedded_arduino/app.py) [1] [2] [3] [4] [5]
• Implemented per-binary fast-flash logic in ArduinoSerial, using esptool's --diff-with with reference binaries to speed up reflashing. Added mechanisms to save and invalidate references, and ensured certain binaries (like boot_app0.bin) are always fully flashed. (pytest_embedded_arduino/serial.py) [1] [2] [3] [4]

Testing and reliability:

• Added an extensive test suite to verify the fast-flash mechanism, including tests for reference path generation, flashing behavior with and without references, error handling, and the effect of disabling fast-flash. (pytest-embedded-arduino/tests/test_arduino.py)

Configuration and integration:

• Added support for a fast_flash/no_fast_flash option in the DUT factory, allowing users to enable or disable the fast-flash feature via test configuration. (pytest_embedded/pytest_embedded/dut_factory.py) [1] [2] [3]

Dependency update:

• Updated the minimum required version of esptool to 5.2 to ensure compatibility with the new fast-flash features. (pytest-embedded-serial-esp/pyproject.toml)

Testing

Tested locally

[github-actions]

Title	Coverage	Tests	Skipped	Failures	Errors	Time
Qemu		7	0 💤	0 ❌	0 🔥	24.632s ⏱️
3.14 X64		117	16 💤	0 ❌	0 🔥	15m 29s ⏱️
3.10 ARM64		117	18 💤	0 ❌	0 🔥	12m 54s ⏱️

[hfudev]

Hi, left a few questions.

[hfudev]

LGTM. i think this is the last one. Also please polish the commit history. This project is using the commit message to generate the release notes.

[hfudev]

Thank you. will do a quick release today