esp-idf/components/fatfs/fatfsgen_utils/fatfs_state.py

114 lines
4.3 KiB
Python

# SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
# SPDX-License-Identifier: Apache-2.0
from textwrap import dedent
from .exceptions import InconsistentFATAttributes
from .utils import (FAT12, FAT12_MAX_CLUSTERS, FAT16, FAT16_MAX_CLUSTERS, 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,
entry_size: int,
sector_size: int,
reserved_sectors_cnt: int,
root_dir_sectors_cnt: int,
size: int,
media_type: int,
sectors_per_fat: 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,
explicit_fat_type: int = None,
long_names_enabled: bool = False):
self._explicit_fat_type = explicit_fat_type
self._binary_image: bytearray = bytearray(b'')
self.fat_tables_cnt: int = fat_tables_cnt
self.oem_name: str = oem_name
self.file_sys_type: str = file_sys_type
self.sec_per_track: int = sec_per_track
self.hidden_sectors: int = hidden_sectors
self.volume_label: str = volume_label
self.media_type: int = media_type
self.long_names_enabled: bool = long_names_enabled
self.entry_size: int = entry_size
self.num_heads: int = num_heads
self.sector_size: int = sector_size
self.root_dir_sectors_cnt: int = root_dir_sectors_cnt
self.reserved_sectors_cnt: int = reserved_sectors_cnt
self.size: int = size
self.sectors_per_fat_cnt: int = sectors_per_fat
self.sectors_per_cluster: int = sectors_per_cluster
if self.clusters 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._binary_image
@binary_image.setter
def binary_image(self, value: bytearray) -> None:
self._binary_image = value
def get_dir_size(self, is_root: bool) -> int:
return self.root_dir_sectors_cnt * self.sector_size if is_root else self.sector_size
@property
def start_address(self) -> int:
return self.sector_size * self.reserved_sectors_cnt
@property
def data_sectors(self) -> int:
return (self.size // self.sector_size) - self.non_data_sectors
@property
def non_data_sectors(self) -> int:
return get_non_data_sectors_cnt(self.reserved_sectors_cnt, self.sectors_per_fat_cnt, # type: ignore
self.root_dir_sectors_cnt)
@property
def data_region_start(self) -> int:
return self.non_data_sectors * self.sector_size
@property
def clusters(self) -> int:
return number_of_clusters(self.data_sectors, self.sectors_per_cluster) # type: ignore
@property
def root_directory_start(self) -> int:
return (self.reserved_sectors_cnt + self.sectors_per_fat_cnt) * self.sector_size
def check_fat_type(self) -> None:
_type = self.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.')
@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 entries_root_count(self) -> int:
return (self.root_dir_sectors_cnt * self.sector_size) // self.entry_size