- Currently, SPIFFS does not support directories, it produces a flat structure. If SPIFFS is mounted under ``/spiffs``, then creating a file with the path ``/spiffs/tmp/myfile.txt`` will create a file called ``/tmp/myfile.txt`` in SPIFFS, instead of ``myfile.txt`` in the directory ``/spiffs/tmp``.
- It is not a real-time stack. One write operation might take much longer than another.
- For now, it does not detect or handle bad blocks.
These optional arguments correspond to a possible SPIFFS build configuration. To generate the right image, please make sure that you use the same arguments/configuration as were used to build SPIFFS. As a guide, the help output indicates the SPIFFS build configuration to which the argument corresponds. In cases when these arguments are not specified, the default values shown in the help output will be used.
Aside from invoking the ``spiffsgen.py`` standalone by manually running it from the command line or a script, it is also possible to invoke ``spiffsgen.py`` directly from the build system by calling ``spiffs_create_partition_image``.
This is more convenient as the build configuration is automatically passed to the tool, ensuring that the generated image is valid for that build. An example of this is while the *image_size* is required for the standalone invocation, only the *partition* name is required when using ``spiffs_create_partition_image`` -- the image size is automatically obtained from the project's partition table.
If FLASH_IN_PROJECT/SPIFFS_IMAGE_FLASH_IN_PROJECT is not specified, the image will still be generated, but you will have to flash it manually using ``esptool.py``, ``parttool.py``, or a custom build system target.
There are cases where the contents of the base directory itself is generated at build time. Users can use DEPENDS/SPIFFS_IMAGE_DEPENDS to specify targets
that should be executed before generating the image.
1. If you want to simply generate a SPIFFS image during the build. ``spiffsgen.py`` makes it very convenient by providing functions/commands from the build system itself.
2. If the host has no C/C++ compiler available, because ``spiffsgen.py`` does not require compilation.
1. If you need to unpack SPIFFS images in addition to image generation. For now, it is not possible with ``spiffsgen.py``.
2. If you have an environment where a Python interpreter is not available, but a host compiler is available. Otherwise, a pre-compiled ``mkspiffs`` binary can do the job. However, there is no build system integration for ``mkspiffs`` and the user has to do the corresponding work: compiling ``mkspiffs`` during build (if a pre-compiled binary is not used), creating build rules/targets for the output files, passing proper parameters to the tool, etc.
An example of using SPIFFS is provided in the :example:`storage/spiffs` directory. This example initializes and mounts a SPIFFS partition, then writes and reads data from it using POSIX and C library APIs. See the README.md file in the example directory for more information.
