Merge branch 'bugfix/fatfs_fatfsparse_relaxed' into 'master'

bugfix(fatfs): Fixed fatfsparse.py parses FAT boot sector too strictly

See merge request espressif/esp-idf!26888

components/fatfs/fatfs_utils/boot_sector.py

@@ -1,9 +1,9 @@
-# SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2021-2023 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 from inspect import getmembers, isroutine
 from typing import Optional
 
-from construct import Const, Int8ul, Int16ul, Int32ul, PaddedString, Struct, core
+from construct import Bytes, Const, Int8ul, Int16ul, Int32ul, PaddedString, Padding, Struct, core
 
 from .exceptions import InconsistentFATAttributes, NotInitialized
 from .fatfs_state import BootSectorState
@@ -29,8 +29,7 @@ class BootSector:
     BOOT_HEADER_SIZE = 512
 
     BOOT_SECTOR_HEADER = Struct(
-        # this value reflects BS_jmpBoot used for ESP32 boot sector (any other accepted)
-        'BS_jmpBoot' / Const(b'\xeb\xfe\x90'),
+        'BS_jmpBoot' / Bytes(3),
         'BS_OEMName' / PaddedString(MAX_OEM_NAME_SIZE, SHORT_NAMES_ENCODING),
         'BPB_BytsPerSec' / Int16ul,
         'BPB_SecPerClus' / Int8ul,
@@ -45,12 +44,12 @@ class BootSector:
         'BPB_HiddSec' / Int32ul,
         'BPB_TotSec32' / Int32ul,  # zero if the FAT type is 12/16, otherwise number of sectors
         'BS_DrvNum' / Const(b'\x80'),
-        'BS_Reserved1' / Const(EMPTY_BYTE),
+        'BS_Reserved1' / Padding(1),
         'BS_BootSig' / Const(b'\x29'),
         'BS_VolID' / Int32ul,
         'BS_VolLab' / PaddedString(MAX_VOL_LAB_SIZE, SHORT_NAMES_ENCODING),
         'BS_FilSysType' / PaddedString(MAX_FS_TYPE_SIZE, SHORT_NAMES_ENCODING),
-        'BS_EMPTY' / Const(448 * EMPTY_BYTE),
+        'BS_EMPTY' / Padding(448),
         'Signature_word' / Const(FATDefaults.SIGNATURE_WORD)
     )
     assert BOOT_SECTOR_HEADER.sizeof() == BOOT_HEADER_SIZE
@@ -73,7 +72,8 @@ class BootSector:
                                      * EMPTY_BYTE)
         self.boot_sector_state.binary_image = (
             BootSector.BOOT_SECTOR_HEADER.build(
-                dict(BS_OEMName=pad_string(boot_sector_state.oem_name, size=BootSector.MAX_OEM_NAME_SIZE),
+                dict(BS_jmpBoot=(b'\xeb\xfe\x90'),
+                     BS_OEMName=pad_string(boot_sector_state.oem_name, size=BootSector.MAX_OEM_NAME_SIZE),
                      BPB_BytsPerSec=boot_sector_state.sector_size,
                      BPB_SecPerClus=boot_sector_state.sectors_per_cluster,
                      BPB_RsvdSecCnt=boot_sector_state.reserved_sectors_cnt,
@@ -91,8 +91,7 @@ class BootSector:
                      BS_VolLab=pad_string(boot_sector_state.volume_label,
                                           size=BootSector.MAX_VOL_LAB_SIZE),
                      BS_FilSysType=pad_string(boot_sector_state.file_sys_type,
-                                              size=BootSector.MAX_FS_TYPE_SIZE)
-                     )
+                                              size=BootSector.MAX_FS_TYPE_SIZE))
             ) + pad_header + fat_tables_content + root_dir_content + data_content
         )
 

components/fatfs/fatfsparse.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-# SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+# SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
 import argparse
 import os
@@ -100,7 +100,7 @@ def remove_wear_levelling_if_exists(fs_: bytes) -> bytes:
         boot_sector__.parse_boot_sector(fs_)
         if boot_sector__.boot_sector_state.size == len(fs_):
             return fs_
-    except construct.core.ConstError:
+    except UnicodeDecodeError:
         pass
     plain_fs: bytes = remove_wl(fs_)
     return plain_fs
@@ -124,6 +124,9 @@ if __name__ == '__main__':
                                  default=None,
                                  help="If detection doesn't work correctly, "
                                       'you can force analyzer to or not to assume WL.')
+    argument_parser.add_argument('--verbose',
+                                 action='store_true',
+                                 help='Prints details about FAT image.')
 
     args = argument_parser.parse_args()
 
@@ -157,6 +160,10 @@ if __name__ == '__main__':
 
     boot_sector_ = BootSector()
     boot_sector_.parse_boot_sector(fs)
+
+    if args.verbose:
+        print(str(boot_sector_))
+
     fat = FAT(boot_sector_.boot_sector_state, init_=False)
 
     boot_dir_start_ = boot_sector_.boot_sector_state.root_directory_start

docs/en/api-reference/storage/fatfs.rst

@@ -136,8 +136,9 @@ It is a reverse tool of (:component_file:`fatfsgen.py <fatfs/fatfsgen.py>`), i.e
 
 Usage::
 
-    ./fatfsparse.py [-h] [--wl-layer {detect,enabled,disabled}] fatfs_image.img
+    ./fatfsparse.py [-h] [--wl-layer {detect,enabled,disabled}] [--verbose] fatfs_image.img
 
+Parameter --verbose prints detailed information from boot sector of the FatFs image to the terminal before folder structure is generated. 
 
 High-level API Reference
 ------------------------

docs/zh_CN/api-reference/storage/fatfs.rst

@@ -136,8 +136,9 @@ FatFs 分区分析器
 
 可以使用::
 
-    ./fatfsparse.py [-h] [--wl-layer {detect,enabled,disabled}] fatfs_image.img
+    ./fatfsparse.py [-h] [--wl-layer {detect,enabled,disabled}] [--verbose] fatfs_image.img
 
+生成文件夹结构之前，参数 --verbose 将根据 FatFs 镜像的引导扇区在终端打印详细信息。
 
 高级 API 参考
 ------------------------