#!/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.exceptions import NoFreeClusterException
from fatfs_utils.fat import FAT
from fatfs_utils.fatfs_state import FATFSState
from fatfs_utils.fs_object import Directory
from fatfs_utils.long_filename_utils import get_required_lfn_entries_count
from fatfs_utils.utils import (BYTES_PER_DIRECTORY_ENTRY, FATFS_INCEPTION, FATFS_MIN_ALLOC_UNIT,
RESERVED_CLUSTERS_COUNT, FATDefaults, get_args_for_partition_generator,
get_fat_sectors_count, get_non_data_sectors_cnt, read_filesystem,
required_clusters_count)
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,
is_empty: bool = False) -> None:
"""
This method allocates necessary clusters and creates a new file record in the directory required.
The directory must exists.
When path_from_root is None the dir is root.
:param name: The name of the file.
:param extension: The extension of the file.
:param path_from_root: List of strings containing names of the ancestor directories in the given order.
:param object_timestamp_: is not None, this will be propagated to the file's entry
:param is_empty: True if there is no need to allocate any cluster, otherwise False
"""
self.root_directory.new_file(name=name,
extension=extension,
path_from_root=path_from_root,
object_timestamp_=object_timestamp_,
is_empty=is_empty)
def create_directory(self, name: str,
path_from_root: Optional[List[str]] = None,
object_timestamp_: datetime = FATFS_INCEPTION) -> None:
"""
Initially recursively finds a parent of the new directory
and then create a new directory inside the parent.
When path_from_root is None the parent dir is root.
:param name: The full name of the directory (excluding its path)
:param path_from_root: List of strings containing names of the ancestor directories in the given order.
:param object_timestamp_: in case the user preserves the timestamps, this will be propagated to the
metadata of the directory (to the corresponding entry)
:returns: None
"""
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,
is_empty=len(content) == 0)
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 calculate_min_space(path: List[str],
fs_entity: str,
sector_size: int = 0x1000,
long_file_names: bool = False,
is_root: bool = False) -> int:
if os.path.isfile(os.path.join(*path, fs_entity)):
with open(os.path.join(*path, fs_entity), 'rb') as file_:
content = file_.read()
res: int = required_clusters_count(sector_size, content)
return res
buff: int = 0
dir_size = 2 * FATDefaults.ENTRY_SIZE # record for symlinks "." and ".."
for file in sorted(os.listdir(os.path.join(*path, fs_entity))):
if long_file_names and True:
# LFN entries + one short entry
dir_size += (get_required_lfn_entries_count(fs_entity) + 1) * FATDefaults.ENTRY_SIZE
else:
dir_size += FATDefaults.ENTRY_SIZE
buff += calculate_min_space(path + [fs_entity], file, sector_size, long_file_names, is_root=False)
if is_root and dir_size // FATDefaults.ENTRY_SIZE > FATDefaults.ROOT_ENTRIES_COUNT:
raise NoFreeClusterException('Not enough space in root!')
# roundup sectors, at least one is required
buff += (dir_size + sector_size - 1) // sector_size
return buff
def main() -> None:
args = get_args_for_partition_generator('Create a FAT filesystem and populate it with directory content', wl=False)
if args.partition_size == -1:
clusters = calculate_min_space([], args.input_directory, args.sector_size, long_file_names=True, is_root=True)
fats = get_fat_sectors_count(clusters, args.sector_size)
root_dir_sectors = (FATDefaults.ROOT_ENTRIES_COUNT * FATDefaults.ENTRY_SIZE) // args.sector_size
args.partition_size = max(FATFS_MIN_ALLOC_UNIT * args.sector_size,
(clusters + fats + get_non_data_sectors_cnt(RESERVED_CLUSTERS_COUNT,
fats,
root_dir_sectors)
) * args.sector_size
)
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()