/*************************************************************************** * Copyright (c) 2024 Microsoft Corporation * * This program and the accompanying materials are made available under the * terms of the MIT License which is available at * https://opensource.org/licenses/MIT. * * SPDX-License-Identifier: MIT **************************************************************************/ /**************************************************************************/ /**************************************************************************/ /** */ /** FileX Component */ /** */ /** Media */ /** */ /**************************************************************************/ /**************************************************************************/ #define FX_SOURCE_CODE /* Include necessary system files. */ #include "fx_api.h" #include "fx_system.h" #include "fx_media.h" #include "fx_utility.h" /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _fx_media_open PORTABLE C */ /* 6.2.0 */ /* AUTHOR */ /* */ /* William E. Lamie, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function opens the specified media with the supplied device */ /* driver. The specified media must conform to the FAT compatible */ /* file format, which is verified during the media open process. In */ /* addition, the supplied FileX device driver must also conform to */ /* the FileX device driver specification. */ /* */ /* The FAT boot sector (512 bytes) that is verified by this */ /* function must look like the following: */ /* */ /* Byte Offset Meaning Size */ /* */ /* 0x000 Jump Instructions 3 */ /* 0x003 OEM Name 8 */ /* 0x00B *Bytes per Sector 2 */ /* 0x00D *Sectors per Cluster 1 */ /* 0x00E *Reserved Sectors 2 */ /* 0x010 *Number of FATs 1 */ /* 0x011 *Max Root Dir Entries 2 */ /* 0x013 *Number of Sectors 2 */ /* 0x015 Media Type 1 */ /* 0x016 *Sectors per FAT 2 */ /* 0x018 *Sectors per Track 2 */ /* 0x01A *Number of Heads 2 */ /* 0x01C *Hidden Sectors 4 */ /* 0x020 *Huge Sectors 4 */ /* 0x024 Drive Number 1 */ /* 0x025 Reserved 1 */ /* 0x026 Boot Signature 1 */ /* 0x027 Volume ID 4 */ /* 0x02B Volume Label 11 */ /* 0x036 File System Type 8 */ /* ... ... ... */ /* 0x1FE **Signature (0x55aa) 2 */ /* */ /* * Denotes which elements of the boot record */ /* FileX uses. */ /* */ /* **Denotes the element is checked by the I/O */ /* driver. This eliminates the need for a minimum */ /* 512-byte buffer for FileX. */ /* */ /* Note: All values above are in little endian format, i.e. the LSB is */ /* in the lowest address. */ /* */ /* INPUT */ /* */ /* media_ptr Media control block pointer */ /* media_name Pointer to media name string */ /* media_driver Media driver entry function */ /* driver_info_ptr Optional information pointer */ /* supplied to media driver */ /* memory_ptr Pointer to memory used by the */ /* FileX for this media. */ /* memory_size Size of media memory - must */ /* at least 512 bytes and */ /* one sector size. */ /* */ /* OUTPUT */ /* */ /* return status */ /* */ /* CALLS */ /* */ /* I/O Driver */ /* _fx_utility_16_unsigned_read Read 16-bit unsigned value */ /* _fx_utility_32_unsigned_read Read 32-bit unsigned value */ /* _fx_utility_logical_sector_flush Invalidate log sector cache */ /* _fx_media_boot_info_extract Extract media information */ /* _fx_utility_FAT_entry_read Pickup FAT entry contents */ /* tx_mutex_create Create protection mutex */ /* */ /* CALLED BY */ /* */ /* Application Code */ /* */ /* RELEASE HISTORY */ /* */ /* DATE NAME DESCRIPTION */ /* */ /* 05-19-2020 William E. Lamie Initial Version 6.0 */ /* 09-30-2020 William E. Lamie Modified comment(s), and */ /* added conditional to */ /* disable force memset, */ /* build options and cache, */ /* resulting in version 6.1 */ /* 01-31-2022 William E. Lamie Modified comment(s), fixed */ /* errors without cache, */ /* resulting in version 6.1.10 */ /* 10-31-2022 Tiejun Zhou Modified comment(s), */ /* fixed memory buffer when */ /* cache is disabled, */ /* resulting in version 6.2.0 */ /* */ /**************************************************************************/ UINT _fx_media_open(FX_MEDIA *media_ptr, CHAR *media_name, VOID (*media_driver)(FX_MEDIA *), VOID *driver_info_ptr, VOID *memory_ptr, ULONG memory_size) { FX_MEDIA_PTR tail_ptr; ULONG cluster_number; ULONG FAT_entry, FAT_sector, FAT_read_sectors; ULONG i, j; #ifndef FX_DISABLE_CACHE FX_CACHED_SECTOR *cache_entry_ptr; #endif /* FX_DISABLE_CACHE */ UINT status; UINT additional_info_sector; UCHAR *original_memory_ptr; ULONG bytes_in_buffer; FX_INT_SAVE_AREA #ifndef FX_DISABLE_BUILD_OPTIONS /* Reference the version ID and option words to ensure they are linked in. */ if ((_fx_system_build_options_1 | _fx_system_build_options_2 | _fx_system_build_options_3) == 0 || _fx_version_id[0] == 0) { /* We should never get here! */ return(FX_NOT_IMPLEMENTED); } #endif /* FX_DISABLE_BUILD_OPTIONS */ #ifdef FX_DISABLE_FORCE_MEMORY_OPERATION _fx_utility_memory_set((UCHAR *)media_ptr, 0, sizeof(FX_MEDIA)); #endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */ #ifdef FX_DISABLE_CACHE media_ptr -> fx_media_memory_buffer_sector = (ULONG64)-1; #endif /* FX_DISABLE_CACHE */ /* Save the basic information in the media control block. */ media_ptr -> fx_media_name = media_name; media_ptr -> fx_media_driver_entry = media_driver; media_ptr -> fx_media_memory_buffer = (UCHAR *)memory_ptr; media_ptr -> fx_media_memory_size = memory_size; #ifndef FX_DISABLE_FORCE_MEMORY_OPERATION media_ptr -> fx_media_disable_burst_cache = FX_FALSE; media_ptr -> fx_media_FAT_type = 0; #endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */ /* Save the original memory pointer. */ original_memory_ptr = (UCHAR *)memory_ptr; #ifndef FX_MEDIA_STATISTICS_DISABLE /* Clear the optional media statistics. */ media_ptr -> fx_media_directory_attributes_reads = 0; media_ptr -> fx_media_directory_attributes_sets = 0; media_ptr -> fx_media_directory_creates = 0; media_ptr -> fx_media_directory_default_gets = 0; media_ptr -> fx_media_directory_default_sets = 0; media_ptr -> fx_media_directory_deletes = 0; media_ptr -> fx_media_directory_first_entry_finds = 0; media_ptr -> fx_media_directory_first_full_entry_finds = 0; media_ptr -> fx_media_directory_information_gets = 0; media_ptr -> fx_media_directory_local_path_clears = 0; media_ptr -> fx_media_directory_local_path_gets = 0; media_ptr -> fx_media_directory_local_path_restores = 0; media_ptr -> fx_media_directory_local_path_sets = 0; media_ptr -> fx_media_directory_name_tests = 0; media_ptr -> fx_media_directory_next_entry_finds = 0; media_ptr -> fx_media_directory_next_full_entry_finds = 0; media_ptr -> fx_media_directory_renames = 0; media_ptr -> fx_media_file_allocates = 0; media_ptr -> fx_media_file_attributes_reads = 0; media_ptr -> fx_media_file_attributes_sets = 0; media_ptr -> fx_media_file_best_effort_allocates = 0; media_ptr -> fx_media_file_closes = 0; media_ptr -> fx_media_file_creates = 0; media_ptr -> fx_media_file_deletes = 0; media_ptr -> fx_media_file_opens = 0; media_ptr -> fx_media_file_reads = 0; media_ptr -> fx_media_file_relative_seeks = 0; media_ptr -> fx_media_file_renames = 0; media_ptr -> fx_media_file_seeks = 0; media_ptr -> fx_media_file_truncates = 0; media_ptr -> fx_media_file_truncate_releases = 0; media_ptr -> fx_media_file_writes = 0; media_ptr -> fx_media_aborts = 0; media_ptr -> fx_media_flushes = 0; media_ptr -> fx_media_reads = 0; media_ptr -> fx_media_writes = 0; media_ptr -> fx_media_directory_entry_reads = 0; media_ptr -> fx_media_directory_entry_writes = 0; media_ptr -> fx_media_directory_searches = 0; #ifndef FX_MEDIA_DISABLE_SEARCH_CACHE media_ptr -> fx_media_directory_search_cache_hits = 0; #endif media_ptr -> fx_media_directory_free_searches = 0; media_ptr -> fx_media_fat_entry_reads = 0; media_ptr -> fx_media_fat_entry_writes = 0; media_ptr -> fx_media_fat_entry_cache_read_hits = 0; media_ptr -> fx_media_fat_entry_cache_read_misses = 0; media_ptr -> fx_media_fat_entry_cache_write_hits = 0; media_ptr -> fx_media_fat_entry_cache_write_misses = 0; media_ptr -> fx_media_fat_cache_flushes = 0; media_ptr -> fx_media_fat_sector_reads = 0; media_ptr -> fx_media_fat_sector_writes = 0; media_ptr -> fx_media_logical_sector_reads = 0; media_ptr -> fx_media_logical_sector_writes = 0; media_ptr -> fx_media_logical_sector_cache_read_hits = 0; media_ptr -> fx_media_logical_sector_cache_read_misses = 0; media_ptr -> fx_media_driver_read_requests = 0; media_ptr -> fx_media_driver_write_requests = 0; media_ptr -> fx_media_driver_boot_read_requests = 0; media_ptr -> fx_media_driver_boot_write_requests = 0; media_ptr -> fx_media_driver_release_sectors_requests = 0; media_ptr -> fx_media_driver_flush_requests = 0; #endif #ifdef FX_ENABLE_FAULT_TOLERANT media_ptr -> fx_media_fault_tolerant_enabled = FX_FALSE; media_ptr -> fx_media_fault_tolerant_state = 0; #endif /* FX_ENABLE_FAULT_TOLERANT */ /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_MEDIA_OPEN, media_ptr, media_driver, memory_ptr, memory_size, FX_TRACE_MEDIA_EVENTS, 0, 0) /* Initialize the supplied media I/O driver. First, build the initialize driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_INIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; media_ptr -> fx_media_driver_info = driver_info_ptr; media_ptr -> fx_media_driver_write_protect = FX_FALSE; media_ptr -> fx_media_driver_free_sector_update = FX_FALSE; media_ptr -> fx_media_driver_data_sector_read = FX_FALSE; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_INIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the initialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Determine if the I/O driver initialized successfully. */ if (media_ptr -> fx_media_driver_status != FX_SUCCESS) { /* Return the driver error status. */ return(FX_IO_ERROR); } #ifndef FX_MEDIA_STATISTICS_DISABLE /* Increment the number of driver boot read requests. */ media_ptr -> fx_media_driver_boot_read_requests++; #endif /* Read the boot sector from the device. Build the read boot sector command. */ media_ptr -> fx_media_driver_request = FX_DRIVER_BOOT_READ; media_ptr -> fx_media_driver_status = FX_IO_ERROR; media_ptr -> fx_media_driver_buffer = memory_ptr; media_ptr -> fx_media_driver_sectors = 1; media_ptr -> fx_media_driver_sector_type = FX_BOOT_SECTOR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_BOOT_READ, media_ptr, memory_ptr, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Invoke the driver to read the boot sector. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Determine if the boot sector was read correctly. */ if (media_ptr -> fx_media_driver_status != FX_SUCCESS) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Return the boot sector error status. */ return(FX_BOOT_ERROR); } /* Extract and validate the media parameters from the boot sector. */ if (_fx_media_boot_info_extract(media_ptr) != FX_SUCCESS) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Return the invalid media error status. */ return(FX_MEDIA_INVALID); } /* Pickup the additional info sector number. This will only be used in FAT32 situations. */ additional_info_sector = _fx_utility_16_unsigned_read(&media_ptr -> fx_media_driver_buffer[48]); /* Is there at least one? */ if (memory_size < media_ptr -> fx_media_bytes_per_sector) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Error in the buffer size supplied by user. */ return(FX_BUFFER_ERROR); } #ifndef FX_DISABLE_CACHE /* Determine how many logical sectors can be cached with user's supplied buffer area - there must be at least enough for one sector! */ media_ptr -> fx_media_sector_cache_size = memory_size / media_ptr -> fx_media_bytes_per_sector; /* If trace is enabled, register this object. */ FX_TRACE_OBJECT_REGISTER(FX_TRACE_OBJECT_TYPE_MEDIA, media_ptr, media_name, FX_MAX_FAT_CACHE, media_ptr -> fx_media_sector_cache_size) /* Adjust the internal cache to fit the fixed number of sector cache control blocks built into the media control block. */ if (media_ptr -> fx_media_sector_cache_size > FX_MAX_SECTOR_CACHE) { /* Adjust the number of cache sectors downward. If this is insufficient, the FX_MAX_SECTOR_CACHE constant in FX_API.H must be changed and the FileX library must be rebuilt. */ media_ptr -> fx_media_sector_cache_size = FX_MAX_SECTOR_CACHE; } /* Otherwise, everything is okay. Initialize the data structures for managing the logical sector cache. */ i = (UINT)media_ptr -> fx_media_sector_cache_size; cache_entry_ptr = media_ptr -> fx_media_sector_cache; while (i--) { /* Initialize each of the cache entries. */ cache_entry_ptr -> fx_cached_sector_memory_buffer = (UCHAR *)memory_ptr; cache_entry_ptr -> fx_cached_sector = (~(ULONG64)0); cache_entry_ptr -> fx_cached_sector_buffer_dirty = FX_FALSE; cache_entry_ptr -> fx_cached_sector_valid = FX_FALSE; cache_entry_ptr -> fx_cached_sector_next_used = cache_entry_ptr + 1; /* Move to the next cache sector entry. */ cache_entry_ptr++; /* Update the memory pointer to the next buffer slot. */ memory_ptr = (VOID *)(((UCHAR *)memory_ptr) + media_ptr -> fx_media_bytes_per_sector); } /* Backup to the last cache entry to set its next pointer to NULL. */ cache_entry_ptr--; cache_entry_ptr -> fx_cached_sector_next_used = FX_NULL; /* Remember the last memory address used by the caching logic. */ media_ptr -> fx_media_sector_cache_end = ((UCHAR *)memory_ptr) - 1; /* Setup the head pointer of the list. */ media_ptr -> fx_media_sector_cache_list_ptr = media_ptr -> fx_media_sector_cache; /* Setup the bit map that keeps track of the valid hashed cache logical sectors. */ media_ptr -> fx_media_sector_cache_hashed_sector_valid = 0; /* Clear the counter of the number of outstanding dirty sectors. */ media_ptr -> fx_media_sector_cache_dirty_count = 0; /* Determine if the logical sector cache should be managed by the hash function instead of the linear search. The cache must be a power of 2 that is between the minimum and maximum cache size. */ if ((media_ptr -> fx_media_sector_cache_size >= FX_SECTOR_CACHE_HASH_ENABLE) && ((media_ptr -> fx_media_sector_cache_size ^ (media_ptr -> fx_media_sector_cache_size - 1)) == (media_ptr -> fx_media_sector_cache_size | (media_ptr -> fx_media_sector_cache_size - 1)))) { /* Set the logical sector cache hash flag. When this flag is set, the logical sector cache is accessed with a hash function instead of a linear search. */ media_ptr -> fx_media_sector_cache_hashed = FX_TRUE; media_ptr -> fx_media_sector_cache_hash_mask = ((media_ptr -> fx_media_sector_cache_size / FX_SECTOR_CACHE_DEPTH) - 1); } else { /* Clear the logical sector cache flag. */ media_ptr -> fx_media_sector_cache_hashed = FX_FALSE; } #else media_ptr -> fx_media_memory_buffer = memory_ptr; #endif /* FX_DISABLE_CACHE */ #ifndef FX_DISABLE_FORCE_MEMORY_OPERATION /* Initialize the FAT cache entry array. */ for (i = 0; i < FX_MAX_FAT_CACHE; i++) { /* Clear entry in the FAT cache. */ media_ptr -> fx_media_fat_cache[i].fx_fat_cache_entry_cluster = 0; media_ptr -> fx_media_fat_cache[i].fx_fat_cache_entry_value = 0; media_ptr -> fx_media_fat_cache[i].fx_fat_cache_entry_dirty = 0; } /* Initialize the secondary FAT update map. */ for (i = 0; i < FX_FAT_MAP_SIZE; i++) { /* Clear bit map entry for secondary FAT update. */ media_ptr -> fx_media_fat_secondary_update_map[i] = 0; } #endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */ /* Root_sector_start has been computed */ media_ptr -> fx_media_root_sector_start = media_ptr -> fx_media_reserved_sectors + (media_ptr -> fx_media_number_of_FATs * media_ptr -> fx_media_sectors_per_FAT); /* Calculate the number of directory sectors. */ media_ptr -> fx_media_root_sectors = ((media_ptr -> fx_media_root_directory_entries * FX_DIR_ENTRY_SIZE) + media_ptr -> fx_media_bytes_per_sector - 1) / media_ptr -> fx_media_bytes_per_sector; /* Calculate the starting data sector. */ media_ptr -> fx_media_data_sector_start = media_ptr -> fx_media_root_sector_start + media_ptr -> fx_media_root_sectors; /* Calculate the total number of clusters. */ media_ptr -> fx_media_total_clusters = (ULONG)((media_ptr -> fx_media_total_sectors - media_ptr -> fx_media_data_sector_start) / media_ptr -> fx_media_sectors_per_cluster); /* Determine if a 12-bit FAT is in use. */ if (media_ptr -> fx_media_total_clusters < FX_12_BIT_FAT_SIZE) { /* Yes, 12-bit FAT is present. Set flag accordingly. */ media_ptr -> fx_media_12_bit_FAT = FX_TRUE; media_ptr -> fx_media_32_bit_FAT = FX_FALSE; /* No additional information sector in FAT12. */ media_ptr -> fx_media_FAT32_additional_info_sector = 0; /* Set FAT last and FAT reserved. */ media_ptr -> fx_media_fat_reserved = FX_RESERVED_1; media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_2; } else if (media_ptr -> fx_media_total_clusters < FX_16_BIT_FAT_SIZE) { /* A 16-bit FAT is present. Set flag accordingly. */ media_ptr -> fx_media_12_bit_FAT = FX_FALSE; media_ptr -> fx_media_32_bit_FAT = FX_FALSE; /* No additional information sector in FAT16. */ media_ptr -> fx_media_FAT32_additional_info_sector = 0; /* Set FAT last and FAT reserved. */ media_ptr -> fx_media_fat_reserved = FX_RESERVED_1; media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_2; } else { /* Yes, a 32-bit FAT is present. */ media_ptr -> fx_media_12_bit_FAT = FX_FALSE; media_ptr -> fx_media_32_bit_FAT = FX_TRUE; /* Save the additional information sector FAT32. This was read from the boot sector earlier in this routine. */ media_ptr -> fx_media_FAT32_additional_info_sector = additional_info_sector; /* Set FAT last and FAT reserved. */ media_ptr -> fx_media_fat_reserved = FX_RESERVED_1_32; media_ptr -> fx_media_fat_last = FX_LAST_CLUSTER_2_32; } /* Determine if a 32-bit FAT is present. If so, calculate the size of the root directory (since it is variable in FAT32. */ if (media_ptr -> fx_media_32_bit_FAT == FX_TRUE) { /* Root First cluster starts from at least cluster 2, or higher. */ if (media_ptr -> fx_media_root_cluster_32 < FX_FAT_ENTRY_START) { return(FX_MEDIA_INVALID); } /* Calculate logical number of root dir sector. */ media_ptr -> fx_media_root_sector_start = media_ptr -> fx_media_data_sector_start + (media_ptr -> fx_media_root_cluster_32 - FX_FAT_ENTRY_START) * media_ptr -> fx_media_sectors_per_cluster; /* Calculate maximum possible value for fx_media_root_directory_entries */ i = 0; for (cluster_number = media_ptr -> fx_media_root_cluster_32;;) { status = _fx_utility_FAT_entry_read(media_ptr, cluster_number, &FAT_entry); i++; /* Determine if the read was successful. */ if (status != FX_SUCCESS) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); return(FX_FAT_READ_ERROR); } if ((cluster_number == FAT_entry) || (i > media_ptr -> fx_media_total_clusters)) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); return(FX_FAT_READ_ERROR); } if (FAT_entry >= FX_RESERVED_1_32) { break; } cluster_number = FAT_entry; } /* Calculate the number of directory entries. */ media_ptr -> fx_media_root_directory_entries = (i * media_ptr -> fx_media_sectors_per_cluster * media_ptr -> fx_media_bytes_per_sector) / FX_DIR_ENTRY_SIZE; } #ifndef FX_DISABLE_FORCE_MEMORY_OPERATION /* Calculate the number of available clusters. */ media_ptr -> fx_media_available_clusters = 0; /* Set the cluster search start to an invalid value. */ media_ptr -> fx_media_cluster_search_start = 0; #endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */ /* Determine if there is 32-bit FAT additional information sector. */ if (media_ptr -> fx_media_FAT32_additional_info_sector) { UCHAR *buffer_ptr; ULONG signature; /* Yes, read the FAT32 additional information sector to get the available cluster count and the hint for the first available cluster. */ #ifndef FX_DISABLE_CACHE /* Setup a pointer to the first cached entry's buffer. */ buffer_ptr = (media_ptr -> fx_media_sector_cache_list_ptr) -> fx_cached_sector_memory_buffer; /* Invalidate this cache entry. */ (media_ptr -> fx_media_sector_cache_list_ptr) -> fx_cached_sector = (~((ULONG64) 0)); (media_ptr -> fx_media_sector_cache_list_ptr) -> fx_cached_sector_valid = FX_FALSE; #else buffer_ptr = media_ptr -> fx_media_memory_buffer; media_ptr -> fx_media_memory_buffer_sector = (ULONG64)-1; #endif /* FX_DISABLE_CACHE */ /* Read the FAT32 additional information sector from the device. */ media_ptr -> fx_media_driver_request = FX_DRIVER_READ; media_ptr -> fx_media_driver_status = FX_IO_ERROR; media_ptr -> fx_media_driver_buffer = buffer_ptr; media_ptr -> fx_media_driver_logical_sector = media_ptr -> fx_media_FAT32_additional_info_sector; media_ptr -> fx_media_driver_sectors = 1; media_ptr -> fx_media_driver_sector_type = FX_DIRECTORY_SECTOR; #ifndef FX_MEDIA_STATISTICS_DISABLE /* Increment the number of driver read sector(s) requests. */ media_ptr -> fx_media_driver_read_requests++; #endif /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_READ, media_ptr, media_ptr -> fx_media_FAT32_additional_info_sector, 1, buffer_ptr, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Invoke the driver to read the FAT32 additional information sector. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Determine if the FAT32 sector was read correctly. */ if (media_ptr -> fx_media_driver_status == FX_SUCCESS) { /* Yes, setup a pointer into the FAT32 additional information sector. */ buffer_ptr = media_ptr -> fx_media_driver_buffer; /* Pickup the first signature long word. */ signature = _fx_utility_32_unsigned_read(&buffer_ptr[0]); /* Determine if the signature is correct. */ if (signature == 0x41615252) { /* Yes, the first signature is correct, now pickup the next signature. */ signature = _fx_utility_32_unsigned_read(&buffer_ptr[484]); /* Determine if this signature is correct. */ if (signature == 0x61417272) { /* Yes, we have a good FAT32 additional information sector. */ /* Pickup the current available cluster count on the media. */ media_ptr -> fx_media_available_clusters = _fx_utility_32_unsigned_read(&buffer_ptr[488]); /* Initialize the last reported available cluster count to the same value. */ media_ptr -> fx_media_FAT32_additional_info_last_available = media_ptr -> fx_media_available_clusters; /* Pickup the hint for the starting free cluster search. */ media_ptr -> fx_media_cluster_search_start = _fx_utility_32_unsigned_read(&buffer_ptr[492]); /* Perform a quick sanity check on the available cluster count and the starting free cluster search. */ if ((media_ptr -> fx_media_available_clusters > media_ptr -> fx_media_total_clusters) || (media_ptr -> fx_media_cluster_search_start > media_ptr -> fx_media_total_clusters + FX_FAT_ENTRY_START) || (media_ptr -> fx_media_cluster_search_start < FX_FAT_ENTRY_START)) { /* Something is wrong, clear the available cluster count and search so the regular processing is used. */ media_ptr -> fx_media_available_clusters = 0; media_ptr -> fx_media_cluster_search_start = 0; /* We don't invalidate the additional info sector here because only the data is bad. */ } } else { /* Signature is bad, invalidate the additional info sector. */ media_ptr -> fx_media_FAT32_additional_info_sector = 0; } } else { /* Signature is bad, invalidate the additional info sector. */ media_ptr -> fx_media_FAT32_additional_info_sector = 0; } } else { /* IO error trying to read additional information sector, invalidate the additional info sector. */ media_ptr -> fx_media_FAT32_additional_info_sector = 0; } } /* Search the media to find the first available cluster as well as the total available clusters. */ /* Determine what type of FAT is present. */ if (media_ptr -> fx_media_12_bit_FAT) { /* A 12-bit FAT is present. Utilize the FAT entry read utility to pickup each FAT entry's contents. */ /* Loop to read each cluster entry in the first FAT. */ for (cluster_number = FX_FAT_ENTRY_START; cluster_number < (media_ptr -> fx_media_total_clusters) + FX_FAT_ENTRY_START; cluster_number++) { /* Read a FAT entry. */ status = _fx_utility_FAT_entry_read(media_ptr, cluster_number, &FAT_entry); /* Determine if the read was successful. */ if (status != FX_SUCCESS) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); return(FX_FAT_READ_ERROR); } /* Now determine if the FAT entry is available. */ if (FAT_entry == FX_FREE_CLUSTER) { /* Increment the number of available clusters. */ media_ptr -> fx_media_available_clusters++; /* Determine if the starting free cluster has been found yet. */ if (media_ptr -> fx_media_cluster_search_start == 0) { /* Remember the first free cluster to start further searches from. */ media_ptr -> fx_media_cluster_search_start = cluster_number; } } } } else if (media_ptr -> fx_media_available_clusters == 0) { /* A 16 or 32-bit FAT is present. Read directly into the logical sector cache memory to optimize I/O on larger devices. Since we are looking for values of zero, endian issues are not important. */ /* Invalidate the current logical sector cache. */ _fx_utility_logical_sector_flush(media_ptr, ((ULONG64) 1), (ULONG64) (media_ptr -> fx_media_total_sectors), FX_TRUE); /* Reset the memory pointer. */ media_ptr -> fx_media_memory_buffer = original_memory_ptr; /* Loop through all FAT sectors in the primary FAT. The first two entries are examined in this loop, but they are always unavailable. */ cluster_number = 0; #ifndef FX_DISABLE_CACHE for (i = 0; i < media_ptr -> fx_media_sectors_per_FAT; i = i + media_ptr -> fx_media_sector_cache_size) { /* Calculate the starting next FAT sector. */ FAT_sector = media_ptr -> fx_media_reserved_sectors + i; /* Calculate how many sectors to read. */ FAT_read_sectors = media_ptr -> fx_media_sectors_per_FAT - i; /* Determine if there is not enough memory to read the remaining FAT sectors. */ if (FAT_read_sectors > media_ptr -> fx_media_sector_cache_size) { FAT_read_sectors = media_ptr -> fx_media_sector_cache_size; } #else for (i = 0; i < media_ptr -> fx_media_sectors_per_FAT; i++) { /* Calculate the starting next FAT sector. */ FAT_sector = media_ptr -> fx_media_reserved_sectors + i; /* Calculate how many sectors to read. */ FAT_read_sectors = 1; #endif /* FX_DISABLE_CACHE */ /* Read the FAT sectors directly from the driver. */ media_ptr -> fx_media_driver_request = FX_DRIVER_READ; media_ptr -> fx_media_driver_status = FX_IO_ERROR; media_ptr -> fx_media_driver_buffer = media_ptr -> fx_media_memory_buffer; media_ptr -> fx_media_driver_logical_sector = FAT_sector; media_ptr -> fx_media_driver_sectors = FAT_read_sectors; media_ptr -> fx_media_driver_sector_type = FX_FAT_SECTOR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_READ, media_ptr, FAT_sector, FAT_read_sectors, media_ptr -> fx_media_memory_buffer, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Invoke the driver to read the FAT sectors. */ (media_ptr -> fx_media_driver_entry) (media_ptr); /* Determine if the read was successful. */ if (media_ptr -> fx_media_driver_status != FX_SUCCESS) { /* Build the "uninitialize" I/O driver request. */ media_ptr -> fx_media_driver_request = FX_DRIVER_UNINIT; media_ptr -> fx_media_driver_status = FX_IO_ERROR; /* If trace is enabled, insert this event into the trace buffer. */ FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_UNINIT, media_ptr, 0, 0, 0, FX_TRACE_INTERNAL_EVENTS, 0, 0) /* Call the specified I/O driver with the uninitialize request. */ (media_ptr -> fx_media_driver_entry) (media_ptr); return(FX_FAT_READ_ERROR); } /* Calculate the number of bytes in the buffer. */ bytes_in_buffer = (media_ptr -> fx_media_bytes_per_sector * FAT_read_sectors); /* Walk through the sector cache memory to search for available clusters and the first available if not already found. */ for (j = 0; j < bytes_in_buffer;) { /* Check for a 32-bit FAT. */ if (media_ptr -> fx_media_32_bit_FAT) { /* Pickup 32-bit FAT entry. */ FAT_entry = *((ULONG *)&(media_ptr -> fx_media_memory_buffer[j])); /* Advance to next FAT entry. */ j = j + 4; } else { /* Process a 16-bit FAT entry. */ FAT_entry = (((ULONG)(media_ptr -> fx_media_memory_buffer[j])) & 0xFF) | ((((ULONG)(media_ptr -> fx_media_memory_buffer[j + 1])) & 0xFF) << 8); /* Advance to next FAT entry. */ j = j + 2; } /* Determine if the FAT entry is free. */ if (FAT_entry == FX_FREE_CLUSTER) { /* Entry is free, increment available clusters. */ media_ptr -> fx_media_available_clusters++; /* Determine if the starting free cluster has been found yet. */ if (media_ptr -> fx_media_cluster_search_start == 0) { /* Remember the first free cluster to start further searches from. */ media_ptr -> fx_media_cluster_search_start = cluster_number; } } /* Increment the cluster number. */ cluster_number++; /* Determine if we have reviewed all FAT entries. */ if (cluster_number >= (media_ptr -> fx_media_total_clusters + FX_FAT_ENTRY_START)) { /* Yes, we have looked at all the FAT entries. */ /* Ensure that the outer loop terminates as well. */ i = media_ptr -> fx_media_sectors_per_FAT; break; } } } } /* If there were no free clusters, just set the search pointer to the first cluster number. */ if (media_ptr -> fx_media_cluster_search_start == 0) { media_ptr -> fx_media_cluster_search_start = FX_FAT_ENTRY_START; } /* Setup the current working directory fields to default to the root directory. */ media_ptr -> fx_media_default_path.fx_path_directory.fx_dir_entry_name = media_ptr -> fx_media_default_path.fx_path_name_buffer; media_ptr -> fx_media_default_path.fx_path_directory.fx_dir_entry_short_name[0] = 0; media_ptr -> fx_media_default_path.fx_path_directory.fx_dir_entry_name[0] = 0; media_ptr -> fx_media_default_path.fx_path_string[0] = (CHAR)0; media_ptr -> fx_media_default_path.fx_path_string[FX_MAXIMUM_PATH - 1] = (CHAR)0; media_ptr -> fx_media_default_path.fx_path_current_entry = 0; #ifndef FX_MEDIA_DISABLE_SEARCH_CACHE /* Invalidate the previously found directory entry. */ media_ptr -> fx_media_last_found_name[0] = 0; #endif #ifndef FX_DISABLE_FORCE_MEMORY_OPERATION /* Initialize the opened file linked list and associated counter. */ media_ptr -> fx_media_opened_file_list = FX_NULL; media_ptr -> fx_media_opened_file_count = 0; #endif /* FX_DISABLE_FORCE_MEMORY_OPERATION */ /* Create the media protection structure if FX_SINGLE_THREAD is not defined. */ #ifndef FX_SINGLE_THREAD #ifndef FX_DONT_CREATE_MUTEX /* Create ThreadX mutex for protection. */ tx_mutex_create(&(media_ptr -> fx_media_protect), "FileX Media Mutex", TX_NO_INHERIT); #endif #endif #ifdef FX_DONT_CREATE_MUTEX /* Load the media ID field in the media control block. This allows the FX_PROTECT call to succeed. */ media_ptr -> fx_media_id = (ULONG)FX_MEDIA_ID; /* Protect against other threads accessing the media. */ FX_PROTECT #endif /* Lockout interrupts. */ FX_DISABLE_INTS /* At this point, the media has been opened successfully. Place the media on the linked list of currently opened media. */ /* Load the media ID field in the media control block. */ media_ptr -> fx_media_id = (ULONG)FX_MEDIA_ID; /* Place the thread on the list of opened media. First, check for an empty list. */ if (_fx_system_media_opened_ptr) { /* Pickup tail pointer. */ tail_ptr = _fx_system_media_opened_ptr -> fx_media_opened_previous; /* Place the new media in the list. */ _fx_system_media_opened_ptr -> fx_media_opened_previous = media_ptr; tail_ptr -> fx_media_opened_next = media_ptr; /* Setup this media's opened links. */ media_ptr -> fx_media_opened_previous = tail_ptr; media_ptr -> fx_media_opened_next = _fx_system_media_opened_ptr; } else { /* The opened media list is empty. Add the media to empty list. */ _fx_system_media_opened_ptr = media_ptr; media_ptr -> fx_media_opened_next = media_ptr; media_ptr -> fx_media_opened_previous = media_ptr; } /* Increment the opened media counter. */ _fx_system_media_opened_count++; /* Invoke media open callback. */ if (media_ptr -> fx_media_open_notify) { media_ptr -> fx_media_open_notify(media_ptr); } /* Restore interrupts. */ FX_RESTORE_INTS #ifdef FX_DONT_CREATE_MUTEX /* Release media protection. */ FX_UNPROTECT #endif /* Return a successful status. */ return(FX_SUCCESS); }