#!/usr/bin/env python
# SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
# SPDX-License-Identifier: Apache-2.0
import os
from datetime import datetime
from typing import Any, List, Optional
from fatfs_utils.boot_sector import BootSector
from fatfs_utils.fat import FAT
from fatfs_utils.fatfs_state import FATFSState
from fatfs_utils.fs_object import Directory
from fatfs_utils.utils import (BYTES_PER_DIRECTORY_ENTRY, FATFS_INCEPTION, FATDefaults,
get_args_for_partition_generator, read_filesystem)
class FATFS:
"""
The class FATFS provides API for generating FAT file system.
It contains reference to the FAT table and to the root directory.
"""
def __init__(self,
binary_image_path: Optional[str] = None,
size: int = FATDefaults.SIZE,
reserved_sectors_cnt: int = FATDefaults.RESERVED_SECTORS_COUNT,
fat_tables_cnt: int = FATDefaults.FAT_TABLES_COUNT,
sectors_per_cluster: int = FATDefaults.SECTORS_PER_CLUSTER,
sector_size: int = FATDefaults.SECTOR_SIZE,
hidden_sectors: int = FATDefaults.HIDDEN_SECTORS,
long_names_enabled: bool = False,
use_default_datetime: bool = True,
num_heads: int = FATDefaults.NUM_HEADS,
oem_name: str = FATDefaults.OEM_NAME,
sec_per_track: int = FATDefaults.SEC_PER_TRACK,
volume_label: str = FATDefaults.VOLUME_LABEL,
file_sys_type: str = FATDefaults.FILE_SYS_TYPE,
root_entry_count: int = FATDefaults.ROOT_ENTRIES_COUNT,
explicit_fat_type: int = None,
media_type: int = FATDefaults.MEDIA_TYPE) -> None:
# root directory bytes should be aligned by sector size
assert (root_entry_count * BYTES_PER_DIRECTORY_ENTRY) % sector_size == 0
# number of bytes in the root dir must be even multiple of BPB_BytsPerSec
assert ((root_entry_count * BYTES_PER_DIRECTORY_ENTRY) // sector_size) % 2 == 0
root_dir_sectors_cnt: int = (root_entry_count * BYTES_PER_DIRECTORY_ENTRY) // sector_size
self.state: FATFSState = FATFSState(sector_size=sector_size,
explicit_fat_type=explicit_fat_type,
reserved_sectors_cnt=reserved_sectors_cnt,
root_dir_sectors_cnt=root_dir_sectors_cnt,
size=size,
file_sys_type=file_sys_type,
num_heads=num_heads,
fat_tables_cnt=fat_tables_cnt,
sectors_per_cluster=sectors_per_cluster,
media_type=media_type,
hidden_sectors=hidden_sectors,
sec_per_track=sec_per_track,
long_names_enabled=long_names_enabled,
volume_label=volume_label,
oem_name=oem_name,
use_default_datetime=use_default_datetime)
binary_image: bytes = bytearray(
read_filesystem(binary_image_path) if binary_image_path else self.create_empty_fatfs())
self.state.binary_image = binary_image
self.fat: FAT = FAT(boot_sector_state=self.state.boot_sector_state, init_=True)
root_dir_size = self.state.boot_sector_state.root_dir_sectors_cnt * self.state.boot_sector_state.sector_size
self.root_directory: Directory = Directory(name='A', # the name is not important, must be string
size=root_dir_size,
fat=self.fat,
cluster=self.fat.clusters[1],
fatfs_state=self.state)
self.root_directory.init_directory()
def create_file(self, name: str,
extension: str = '',
path_from_root: Optional[List[str]] = None,
object_timestamp_: datetime = FATFS_INCEPTION) -> None:
# when path_from_root is None the dir is root
self.root_directory.new_file(name=name,
extension=extension,
path_from_root=path_from_root,
object_timestamp_=object_timestamp_)
def create_directory(self, name: str,
path_from_root: Optional[List[str]] = None,
object_timestamp_: datetime = FATFS_INCEPTION) -> None:
# when path_from_root is None the dir is root
parent_dir = self.root_directory
if path_from_root:
parent_dir = self.root_directory.recursive_search(path_from_root, self.root_directory)
self.root_directory.new_directory(name=name,
parent=parent_dir,
path_from_root=path_from_root,
object_timestamp_=object_timestamp_)
def write_content(self, path_from_root: List[str], content: bytes) -> None:
"""
fat fs invokes root directory to recursively find the required file and writes the content
"""
self.root_directory.write_to_file(path_from_root, content)
def create_empty_fatfs(self) -> Any:
boot_sector_ = BootSector(boot_sector_state=self.state.boot_sector_state)
boot_sector_.generate_boot_sector()
return boot_sector_.binary_image
def write_filesystem(self, output_path: str) -> None:
with open(output_path, 'wb') as output:
output.write(bytearray(self.state.binary_image))
def _generate_partition_from_folder(self,
folder_relative_path: str,
folder_path: str = '',
is_dir: bool = False) -> None:
"""
Given path to folder and folder name recursively encodes folder into binary image.
Used by method generate.
"""
real_path: str = os.path.join(folder_path, folder_relative_path)
lower_path: str = folder_relative_path
folder_relative_path = folder_relative_path.upper()
normal_path = os.path.normpath(folder_relative_path)
split_path = normal_path.split(os.sep)
object_timestamp = datetime.fromtimestamp(os.path.getctime(real_path))
if os.path.isfile(real_path):
with open(real_path, 'rb') as file:
content = file.read()
file_name, extension = os.path.splitext(split_path[-1])
extension = extension[1:] # remove the dot from the extension
self.create_file(name=file_name,
extension=extension,
path_from_root=split_path[1:-1] or None,
object_timestamp_=object_timestamp)
self.write_content(split_path[1:], content)
elif os.path.isdir(real_path):
if not is_dir:
self.create_directory(name=split_path[-1],
path_from_root=split_path[1:-1],
object_timestamp_=object_timestamp)
# sorting files for better testability
dir_content = list(sorted(os.listdir(real_path)))
for path in dir_content:
self._generate_partition_from_folder(os.path.join(lower_path, path), folder_path=folder_path)
def generate(self, input_directory: str) -> None:
"""
Normalize path to folder and recursively encode folder to binary image
"""
path_to_folder, folder_name = os.path.split(input_directory)
self._generate_partition_from_folder(folder_name, folder_path=path_to_folder, is_dir=True)
def main() -> None:
args = get_args_for_partition_generator('Create a FAT filesystem and populate it with directory content')
if args.sector_size != 0x1000:
raise NotImplementedError('The sector size not equal to 4096 is currently not supported for read-only mode!')
fatfs = FATFS(sector_size=args.sector_size,
sectors_per_cluster=args.sectors_per_cluster,
size=args.partition_size,
root_entry_count=args.root_entry_count,
explicit_fat_type=args.fat_type,
long_names_enabled=args.long_name_support,
use_default_datetime=args.use_default_datetime)
fatfs.generate(args.input_directory)
fatfs.write_filesystem(args.output_file)
if __name__ == '__main__':
main()