README.md
Supported Targets | ESP32 | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-S2 | ESP32-S3 |
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FATFS partition generation example
(See the README.md file in the upper level 'examples' directory for more information about examples.)
This example demonstrates how to use the FATFS partition
generation tool fatfsgen.py to automatically create a FATFS
filesystem image from the contents of a host folder during build, with an option of
automatically flashing the created image on invocation of idf.py -p PORT flash
.
Beware that the minimal required size of the flash is 4 MB.
You can specify using menuconfig weather example will use read-only or read-write mode. The default option is read-write mode.
To change it just use menuconfig:
idf.py menuconfig
Then select Example Configuration
a chose Mode for generated FATFS image
either Read-Write Mode
or Read-Only Mode
.
Read-Only
option indicates generating raw fatfs image without wear levelling support.
On the other hand, for Read-Write
the generated fatfs image will support wear levelling thus can be mounted in read-write mode.
The following gives an overview of the example:
-
There is a directory
fatfs_image
from which the FATFS filesystem image will be created. -
The function
fatfs_create_rawflash_image
is used to specify that a FATFS image should be created during build for thestorage
partition. For CMake, it is called from the main component's CMakeLists.txt.FLASH_IN_PROJECT
specifies that the created image should be flashed on invocation ofidf.py -p PORT flash
together with app, bootloader, partition table, etc. The image is created on the example's build directory with the output filenamestorage.bin
. -
Upon invocation of
idf.py -p PORT flash monitor
, application loads and finds there is already a valid FATFS filesystem in thestorage
partition with files same as those infatfs_image
directory. The application is then able to read those files.
How to use example
Build and flash
To run the example, type the following command:
# CMake
idf.py -p PORT flash monitor
(To exit the serial monitor, type Ctrl-]
.)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
Example output
Here is the example's console output:
...
I (322) example: Mounting FAT filesystem
I (332) example: Reading file
I (332) example: Read from file: 'this is test'
I (332) example: Unmounting FAT filesystem
I (342) example: Done
The logic of the example is contained in a single source file, and it should be relatively simple to match points in its execution with the log outputs above.