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# SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
# SPDX-License-Identifier: Apache-2.0
from textwrap import dedent
from typing import Optional
from .exceptions import InconsistentFATAttributes
from .utils import (ALLOWED_SECTOR_SIZES, FAT12, FAT12_MAX_CLUSTERS, FAT16, FAT16_MAX_CLUSTERS,
RESERVED_CLUSTERS_COUNT, FATDefaults, get_fat_sectors_count, get_fatfs_type,
get_non_data_sectors_cnt, number_of_clusters)
class FATFSState:
"""
The class represents the state and the configuration of the FATFS.
"""
def __init__(self,
sector_size: int,
reserved_sectors_cnt: int,
root_dir_sectors_cnt: int,
size: int,
media_type: int,
sectors_per_cluster: int,
volume_label: str,
oem_name: str,
fat_tables_cnt: int,
sec_per_track: int,
num_heads: int,
hidden_sectors: int,
file_sys_type: str,
use_default_datetime: bool,
explicit_fat_type: Optional[int] = None,
long_names_enabled: bool = False):
self.boot_sector_state = BootSectorState(oem_name=oem_name,
sector_size=sector_size,
sectors_per_cluster=sectors_per_cluster,
reserved_sectors_cnt=reserved_sectors_cnt,
fat_tables_cnt=fat_tables_cnt,
root_dir_sectors_cnt=root_dir_sectors_cnt,
sectors_count=size // sector_size,
media_type=media_type,
sec_per_track=sec_per_track,
num_heads=num_heads,
hidden_sectors=hidden_sectors,
volume_label=volume_label,
file_sys_type=file_sys_type,
volume_uuid=-1)
self._explicit_fat_type: Optional[int] = explicit_fat_type
self.long_names_enabled: bool = long_names_enabled
self.use_default_datetime: bool = use_default_datetime
if (size // sector_size) * sectors_per_cluster in (FAT12_MAX_CLUSTERS, FAT16_MAX_CLUSTERS):
print('WARNING: It is not recommended to create FATFS with bounding '
f'count of clusters: {FAT12_MAX_CLUSTERS} or {FAT16_MAX_CLUSTERS}')
self.check_fat_type()
@property
def binary_image(self) -> bytearray:
return self.boot_sector_state.binary_image
@binary_image.setter
def binary_image(self, value: bytearray) -> None:
self.boot_sector_state.binary_image = value
def check_fat_type(self) -> None:
_type = self.boot_sector_state.fatfs_type
if self._explicit_fat_type is not None and self._explicit_fat_type != _type:
raise InconsistentFATAttributes(dedent(
f"""FAT type you specified is inconsistent with other attributes of the system.
The specified FATFS type: FAT{self._explicit_fat_type}
The actual FATFS type: FAT{_type}"""))
if _type not in (FAT12, FAT16):
raise NotImplementedError('FAT32 is currently not supported.')
class BootSectorState:
# pylint: disable=too-many-instance-attributes
def __init__(self,
oem_name: str,
sector_size: int,
sectors_per_cluster: int,
reserved_sectors_cnt: int,
fat_tables_cnt: int,
root_dir_sectors_cnt: int,
sectors_count: int,
media_type: int,
sec_per_track: int,
num_heads: int,
hidden_sectors: int,
volume_label: str,
file_sys_type: str,
volume_uuid: int = -1) -> None:
self.oem_name: str = oem_name
self.sector_size: int = sector_size
assert self.sector_size in ALLOWED_SECTOR_SIZES
self.sectors_per_cluster: int = sectors_per_cluster
self.reserved_sectors_cnt: int = reserved_sectors_cnt
self.fat_tables_cnt: int = fat_tables_cnt
self.root_dir_sectors_cnt: int = root_dir_sectors_cnt
self.sectors_count: int = sectors_count
self.media_type: int = media_type
self.sectors_per_fat_cnt = get_fat_sectors_count(self.size // self.sector_size, self.sector_size)
self.sec_per_track: int = sec_per_track
self.num_heads: int = num_heads
self.hidden_sectors: int = hidden_sectors
self.volume_label: str = volume_label
self.file_sys_type: str = file_sys_type
self.volume_uuid: int = volume_uuid
self._binary_image: bytearray = bytearray(b'')
@property
def binary_image(self) -> bytearray:
return self._binary_image
@binary_image.setter
def binary_image(self, value: bytearray) -> None:
self._binary_image = value
@property
def size(self) -> int:
return self.sector_size * self.sectors_count
@property
def data_region_start(self) -> int:
return self.non_data_sectors * self.sector_size
@property
def fatfs_type(self) -> int:
# variable typed_fatfs_type must be explicitly typed to avoid mypy error
typed_fatfs_type: int = get_fatfs_type(self.clusters)
return typed_fatfs_type
@property
def clusters(self) -> int:
"""
The actual number of clusters is calculated by `number_of_clusters`,
however, the initial two blocks of FAT are reserved (device type and root directory),
despite they don't refer to the data region.
Since that, two clusters are added to use the full potential of the FAT file system partition.
"""
clusters_cnt_: int = number_of_clusters(self.data_sectors, self.sectors_per_cluster) + RESERVED_CLUSTERS_COUNT
return clusters_cnt_
@property
def data_sectors(self) -> int:
# self.sector_size is checked in constructor if has one of allowed values (ALLOWED_SECTOR_SIZES)
return (self.size // self.sector_size) - self.non_data_sectors
@property
def non_data_sectors(self) -> int:
non_data_sectors_: int = get_non_data_sectors_cnt(self.reserved_sectors_cnt,
self.sectors_per_fat_cnt,
self.fat_tables_cnt,
self.root_dir_sectors_cnt)
return non_data_sectors_
@property
def fat_table_start_address(self) -> int:
return self.sector_size * self.reserved_sectors_cnt
@property
def entries_root_count(self) -> int:
entries_root_count_: int = (self.root_dir_sectors_cnt * self.sector_size) // FATDefaults.ENTRY_SIZE
return entries_root_count_
@property
def root_directory_start(self) -> int:
root_dir_start: int = (self.reserved_sectors_cnt + self.sectors_per_fat_cnt * self.fat_tables_cnt) * self.sector_size
return root_dir_start
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