Merge branch 'docs/external_flash_5.2' into 'release/v5.2'

docs(idf_py): Describe the option to configure esptool.py with --extra-args (backport to v5.2)

See merge request espressif/esp-idf!30323

docs/en/api-guides/tools/idf-py.rst

@@ -120,6 +120,8 @@ This command automatically builds the project if necessary, and then flash it to
 
 .. note:: The environment variables ``ESPPORT`` and ``ESPBAUD`` can be used to set default values for the ``-p`` and ``-b`` options, respectively. Providing these options on the command line overrides the default.
 
+``idf.py`` uses the ``write_flash`` command of ``esptool.py`` under the hood to flash the target. You can pass additional arguments to configure the flash writing process using the ``--extra-args`` option. For example, to `write to an external SPI flash chip <https://docs.espressif.com/projects/esptool/en/latest/esptool/advanced-options.html#custom-spi-pin-configuration>`_, use the following command: ``idf.py flash --extra-args="--spi-connection <CLK>,<Q>,<D>,<HD>,<CS>"``. To see the full list of available arguments, run ``esptool.py write_flash --help`` or see the `esptool.py documentation <https://docs.espressif.com/projects/esptool/en/latest/esptool/index.html>`_.
+
 Similarly to the ``build`` command, the command can be run with ``app``, ``bootloader`` and ``partition-table`` arguments to flash only the app, bootloader or partition table as applicable.
 
 Hints on How to Resolve Errors

docs/en/api-reference/storage/spiffs.rst

@@ -85,6 +85,10 @@ To flash the image onto {IDF_TARGET_NAME} at offset 0x110000, run::
 
     python esptool.py --chip {IDF_TARGET_PATH_NAME} --port [port] --baud [baud] write_flash -z 0x110000 spiffs.bin
 
+.. note::
+
+    You can configure the ``write_flash`` command of ``esptool.py`` to `write the spiffs data to an external SPI flash chip <https://docs.espressif.com/projects/esptool/en/latest/esptool/advanced-options.html#custom-spi-pin-configuration>`_ using the ``--spi-connection <CLK>,<Q>,<D>,<HD>,<CS>`` option. Just specify the GPIO pins assigned to the external flash, e.g. ``python esptool.py write_flash --spi-connection 6,7,8,9,11 -z 0x110000 spiffs.bin``.
+
 Notes on Which SPIFFS Tool to Use
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~