During the write access to the SPI flash, the IROM cache is not available and only code from the IRAM can be executed. Therefore, the code of file system implementations which access the SPI flash must reside in IRAM.
ESP32 nodes can crash during SPI Flash write operations if required parts of the code are not in the IRAM but in the cached SPI Flash memory, which is disabled during the SPI Flash write operations. Therefore, the code of the SPIFFS package and the VFS module are now stored in the IRAM.
