fs/fat_fs_api/prj.conf

CONFIG_FILE_SYSTEM=y
CONFIG_FILE_SYSTEM_MKFS=y
CONFIG_LOG=y
CONFIG_FAT_FILESYSTEM_ELM=y
CONFIG_DISK_DRIVER_FLASH=y
CONFIG_ZTEST=y
CONFIG_FLASH=y
CONFIG_FLASH_MAP=y

# Demonstrate filesystem time integration
CONFIG_FS_FATFS_HAS_RTC=y