forked from FreeRTOS/Lab-Project-FreeRTOS-FAT
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ff_fat.c
executable file
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ff_fat.c
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/*
* FreeRTOS+FAT V2.3.3
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/**
* @file ff_fat.c
* @ingroup FAT
*
* @defgroup FAT Fat File-System
* @brief Handles FAT access and traversal.
*
* Provides file-system interfaces for the FAT file-system.
**/
#include "ff_headers.h"
#include <string.h>
#if ffconfigFAT_USES_STAT
/* This module make use of a buffer caching called 'FF_FATBuffers_t'.
* The struct below may gather statistics about its usage: hits/misses.
*/
struct SFatStat fatStat;
#endif /* ffconfigFAT_USES_STAT */
/* prvGetFromFATBuffers() will see if the FF_Buffer_t pointed to by ppxBuffer contains the
* buffer that is needed, i.e. opened for the same sector and with the correct R/W mode.
* If ppxBuffer is NULL or if it can not be used, a new buffer will be created.
* The buffer pointed to by ppxBuffer will either be released or its pointer will be returned.
*/
FF_Buffer_t * prvGetFromFATBuffers( FF_IOManager_t * pxIOManager,
FF_FATBuffers_t * pxFATBuffers,
BaseType_t xBufferIndex,
uint32_t ulFATSector,
FF_Error_t * pxError,
uint8_t ucMode );
#if ( ffconfigFAT12_SUPPORT != 0 )
/* A very special case for FAT12: an entry is stored in two sectors.
* Read the two sectors and merge the two values found.
*/
static uint32_t prvGetFAT12Entry( FF_IOManager_t * pxIOManager,
FF_Error_t * pxError,
FF_FATBuffers_t * pxFATBuffers,
uint32_t ulFATSector );
#endif
#if ( ffconfigFAT12_SUPPORT != 0 )
/* Same as above: put a FAT12 entry that is spread-out over two sectors.
* Read the current value first to preserve and merge the earlier 4 bits
* of an adjacent FAT12 entry.
*/
static FF_Error_t prvPutFAT12Entry( FF_IOManager_t * pxIOManager,
uint32_t ulCluster,
uint32_t ulValue,
FF_FATBuffers_t * pxFATBuffers,
uint32_t ulFATSector );
#endif
#if ( ffconfigFAT12_SUPPORT != 0 )
/* A generic less-optimised way of finding the first free cluster.
* Used for FAT12 only.
*/
static uint32_t prvFindFreeClusterSimple( FF_IOManager_t * pxIOManager,
FF_Error_t * pxError );
#endif /* ffconfigFAT12_SUPPORT */
#if ( ffconfigFAT12_SUPPORT != 0 )
/* A generic less-optimised way of counting free clusters.
* Used for FAT12 only.
*/
static uint32_t prvCountFreeClustersSimple( FF_IOManager_t * pxIOManager,
FF_Error_t * pxError );
#endif /* ffconfigFAT12_SUPPORT */
/* Have a cluster number and translate it to an LBA (Logical Block Address).
* 'ulSectorsPerCluster' should be seen as 'blocks per cluster', where the length of one
* block is defined in the PBR (Partition Boot Record) at FF_FAT_BYTES_PER_SECTOR (offset 0x0B).
*/
uint32_t FF_Cluster2LBA( FF_IOManager_t * pxIOManager,
uint32_t ulCluster )
{
uint32_t ulLBA = 0;
FF_Partition_t * pxPartition;
if( pxIOManager != NULL )
{
pxPartition = &( pxIOManager->xPartition );
if( ulCluster >= 2 )
{
ulLBA = ( ( ulCluster - 2 ) * pxPartition->ulSectorsPerCluster ) + pxPartition->ulFirstDataSector;
}
else
{
ulLBA = pxPartition->ulClusterBeginLBA;
}
}
return ulLBA;
}
/*-----------------------------------------------------------*/
/*
* Major and Minor sectors/blocks:
*
* A cluster is defined as N "sectors". Those sectors in fact are "major blocks"
* whose size is defined in a field called 'FF_FAT_BYTES_PER_SECTOR' in the PBR.
*
* I/O to the disk takes place in "minor block" of usually 512 byte and the addressing
* is also based on "minor block" sector numbers.
*
* In most cases, Major == Minor == 512 bytes.
*
* Here below some translations are done for 'entries', which can be 1-byte entries
* as well as the 32-byte directory entries.
*
*/
/* Translate an 'entry number' (ulEntry) to a relative cluster number,
* where e.g. 'ulEntry' may be a sequence number of a directory entry for
* which ulEntrySize = 32 bytes.
*/
uint32_t FF_getClusterChainNumber( FF_IOManager_t * pxIOManager,
uint32_t ulEntry,
uint32_t ulEntrySize )
{
uint32_t ulBytesPerCluster = pxIOManager->xPartition.usBlkSize * pxIOManager->xPartition.ulSectorsPerCluster;
uint32_t ulEntriesPerCluster = ( ulBytesPerCluster / ulEntrySize );
/* E.g. ulBytesPerCluster = 16384, ulEntrySize = 32: 16384 / 32 = 512 entries per cluster. */
return ulEntry / ulEntriesPerCluster;
}
/*-----------------------------------------------------------*/
/* If the above function returns a cluster number, this function
* returns a BYTE position within that cluster. */
uint32_t FF_getClusterPosition( FF_IOManager_t * pxIOManager,
uint32_t ulEntry,
uint32_t ulEntrySize )
{
uint32_t ulBytesPerCluster = pxIOManager->xPartition.usBlkSize * pxIOManager->xPartition.ulSectorsPerCluster;
uint32_t ulEntriesPerCluster = ( ulBytesPerCluster / ulEntrySize );
/* Return the block offset within the current cluster: */
return ( ulEntry % ulEntriesPerCluster ) * ulEntrySize;
}
/*-----------------------------------------------------------*/
/* Return the block offset (= number of major blocks) within the current cluster: */
uint32_t FF_getMajorBlockNumber( FF_IOManager_t * pxIOManager,
uint32_t ulEntry,
uint32_t ulEntrySize )
{
uint32_t ulBytesPerCluster = pxIOManager->xPartition.usBlkSize * pxIOManager->xPartition.ulSectorsPerCluster;
uint32_t ulEntriesPerCluster = ( ulBytesPerCluster / ulEntrySize );
uint32_t ulRelClusterEntry;
/* Calculate the entry number within a cluster: */
ulRelClusterEntry = ulEntry % ulEntriesPerCluster;
/* Return the block offset within the current cluster: */
return ulRelClusterEntry / ( pxIOManager->xPartition.usBlkSize / ulEntrySize );
}
/*-----------------------------------------------------------*/
/* Return the minor block number within the current major block */
uint32_t FF_getMinorBlockNumber( FF_IOManager_t * pxIOManager,
uint32_t ulEntry,
uint32_t ulEntrySize )
{
uint32_t ulBytesPerCluster = pxIOManager->xPartition.usBlkSize * pxIOManager->xPartition.ulSectorsPerCluster;
uint32_t ulEntriesPerCluster = ( ulBytesPerCluster / ulEntrySize );
uint32_t ulRelClusterEntry;
uint32_t ulRelMajorBlockEntry;
/* Calculate the entry number within a cluster: */
ulRelClusterEntry = ulEntry % ulEntriesPerCluster;
ulRelMajorBlockEntry = ulRelClusterEntry % ( pxIOManager->xPartition.usBlkSize / ulEntrySize );
return ulRelMajorBlockEntry / ( pxIOManager->usSectorSize / ulEntrySize );
}
/*-----------------------------------------------------------*/
/* Get the entry number within the minor block */
uint32_t FF_getMinorBlockEntry( FF_IOManager_t * pxIOManager,
uint32_t ulEntry,
uint32_t ulEntrySize )
{
uint32_t ulBytesPerCluster = pxIOManager->xPartition.usBlkSize * pxIOManager->xPartition.ulSectorsPerCluster;
uint32_t ulEntriesPerCluster = ( ulBytesPerCluster / ulEntrySize );
uint32_t ulRelClusterEntry;
uint32_t ulRelMajorBlockEntry;
/* Calculate the entry number within a cluster: */
ulRelClusterEntry = ulEntry % ulEntriesPerCluster;
ulRelMajorBlockEntry = ulRelClusterEntry % ( pxIOManager->xPartition.usBlkSize / ulEntrySize );
return ulRelMajorBlockEntry % ( pxIOManager->usSectorSize / ulEntrySize );
}
/*-----------------------------------------------------------*/
FF_Error_t FF_ReleaseFATBuffers( FF_IOManager_t * pxIOManager,
FF_FATBuffers_t * pxFATBuffers )
{
BaseType_t xIndex;
FF_Error_t xError = FF_ERR_NONE;
FF_Buffer_t * pxBuffer;
#if ffconfigBUF_STORE_COUNT != 2
#warning Only maintaining one FAT table
#endif
/* 'ffconfigBUF_STORE_COUNT' equals to the number of FAT tables. */
for( xIndex = 0; xIndex < ffconfigBUF_STORE_COUNT; xIndex++ )
{
pxBuffer = pxFATBuffers->pxBuffers[ xIndex ];
if( pxBuffer != NULL )
{
FF_Error_t xTempError = FF_ERR_NONE;
pxFATBuffers->pxBuffers[ xIndex ] = NULL;
xTempError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
if( FF_isERR( xError ) == pdFALSE )
{
/* as everywhere, this function will return
* the first error that occurred, if any. */
xError = xTempError;
}
}
}
#if ffconfigFAT_USES_STAT
{
fatStat.clearCount++;
}
#endif /* ffconfigFAT_USES_STAT */
return xError;
}
/*-----------------------------------------------------------*/
FF_Buffer_t * prvGetFromFATBuffers( FF_IOManager_t * pxIOManager,
FF_FATBuffers_t * pxFATBuffers,
BaseType_t xBufferIndex,
uint32_t ulFATSector,
FF_Error_t * pxError,
uint8_t ucMode )
{
FF_Error_t xError = FF_ERR_NONE;
FF_Buffer_t * pxBuffer = NULL;
if( pxFATBuffers != NULL )
{
/* See if the same buffer can be reused. */
pxBuffer = pxFATBuffers->pxBuffers[ xBufferIndex ];
if( pxBuffer != NULL )
{
/* Now the buffer is either owned by pxBuffer,
* or it has been released, so put it to NULL. */
pxFATBuffers->pxBuffers[ xBufferIndex ] = NULL;
if(
( pxBuffer->ulSector == ulFATSector ) &&
( ( ( ucMode & FF_MODE_WRITE ) == 0 ) ||
( ( pxBuffer->ucMode & FF_MODE_WRITE ) != 0 ) )
)
{
/* Same sector, AND
* write-permission is not required OR the buffer has write permission:
* it can be reused. */
#if ffconfigFAT_USES_STAT
{
fatStat.reuseCount[ ( ucMode & FF_MODE_WRITE ) ? 1 : 0 ]++;
}
#endif /* ffconfigFAT_USES_STAT */
}
else
{
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
pxBuffer = NULL;
#if ffconfigFAT_USES_STAT
{
fatStat.missCount[ ( ucMode & FF_MODE_WRITE ) ? 1 : 0 ]++;
}
#endif /* ffconfigFAT_USES_STAT */
}
}
else
{
#if ffconfigFAT_USES_STAT
{
fatStat.getCount[ ( ucMode & FF_MODE_WRITE ) ? 1 : 0 ]++;
}
#endif /* ffconfigFAT_USES_STAT */
}
}
if( ( pxBuffer == NULL ) && ( FF_isERR( xError ) == pdFALSE ) )
{
pxBuffer = FF_GetBuffer( pxIOManager, ulFATSector, ucMode );
if( pxBuffer == NULL )
{
/* Setting an error code without the Module/Function,
* will be filled-in by the caller. */
xError = ( FF_Error_t ) ( FF_ERR_DEVICE_DRIVER_FAILED | FF_ERRFLAG );
}
}
*pxError = xError;
return pxBuffer;
}
#if ( ffconfigFAT12_SUPPORT != 0 )
/* A very special case for FAT12: an entry is stored in two sectors.
* Read the two sectors and merge the two values found. */
static uint32_t prvGetFAT12Entry( FF_IOManager_t * pxIOManager,
FF_Error_t * pxError,
FF_FATBuffers_t * pxFATBuffers,
uint32_t ulFATSector )
{
FF_Error_t xError = FF_ERR_NONE;
FF_Buffer_t * pxBuffer = NULL;
/* preferred buffer access mode, user might want to update this entry
* and set it to FF_MODE_WRITE. */
uint8_t ucMode = pxFATBuffers ? pxFATBuffers->ucMode : FF_MODE_READ;
/* Collect the two bytes in an array. */
uint8_t ucBytes[ 2 ];
/* The function return value. */
uint32_t ulFATEntry = 0UL;
pxBuffer = prvGetFromFATBuffers( pxIOManager, pxFATBuffers, 0, ulFATSector, &xError, ucMode );
if( FF_isERR( xError ) )
{
xError = FF_GETERROR( xError ) | FF_GETFATENTRY;
}
else
{
/* Fetch the very last byte of this segment. */
ucBytes[ 0 ] = FF_getChar( pxBuffer->pucBuffer, ( uint16_t ) ( pxIOManager->usSectorSize - 1 ) );
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
/* release the other buffer as well. */
if( ( FF_isERR( xError ) == pdFALSE ) && ( pxFATBuffers != NULL ) )
{
xError = FF_ReleaseFATBuffers( pxIOManager, pxFATBuffers );
}
if( FF_isERR( xError ) == pdFALSE )
{
/* Second Buffer get the first Byte in buffer (second byte of out address)! */
pxBuffer = FF_GetBuffer( pxIOManager, ulFATSector + 1, ucMode );
if( pxBuffer == NULL )
{
xError = ( FF_Error_t ) ( FF_ERR_DEVICE_DRIVER_FAILED | FF_GETFATENTRY );
}
else
{
/* Read the first byte from the subsequent sector. */
ucBytes[ 1 ] = FF_getChar( pxBuffer->pucBuffer, 0 );
/* And release that buffer. */
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
if( FF_isERR( xError ) == pdFALSE )
{
/* Join the two bytes: */
ulFATEntry = ( uint32_t ) FF_getShort( ( uint8_t * ) ucBytes, 0 );
}
}
}
}
*pxError = xError;
return ( int32_t ) ulFATEntry;
}
#endif /* ffconfigFAT12_SUPPORT */
/*-----------------------------------------------------------*/
/* Get a FAT entry, which is nothing more than a number referring to a sector. */
uint32_t FF_getFATEntry( FF_IOManager_t * pxIOManager,
uint32_t ulCluster,
FF_Error_t * pxError,
FF_FATBuffers_t * pxFATBuffers )
{
FF_Buffer_t * pxBuffer = NULL;
uint32_t ulFATOffset;
uint32_t ulFATSector = 0;
uint32_t ulFATSectorEntry;
/* The function result. */
uint32_t ulFATEntry = 0;
uint32_t ulLBAAdjust;
uint32_t ulRelClusterEntry = 0;
FF_Error_t xError = FF_ERR_NONE;
/* preferred mode, user might want to update this entry. */
uint8_t ucMode = pxFATBuffers ? pxFATBuffers->ucMode : FF_MODE_READ;
FF_Assert_Lock( pxIOManager, FF_FAT_LOCK );
if( ulCluster >= pxIOManager->xPartition.ulNumClusters )
{
/* _HT_ find a more specific error code.
* Probably not really important as this is a function internal to the library. */
xError = ( FF_Error_t ) ( FF_ERR_IOMAN_NOT_ENOUGH_FREE_SPACE | FF_GETFATENTRY );
}
else
{
if( pxIOManager->xPartition.ucType == FF_T_FAT32 )
{
ulFATOffset = ulCluster * 4;
}
else if( pxIOManager->xPartition.ucType == FF_T_FAT16 )
{
ulFATOffset = ulCluster * 2;
}
else /* pxIOManager->xPartition.ucType == FF_T_FAT12 */
{
ulFATOffset = ulCluster + ( ulCluster / 2 );
}
ulFATSector = pxIOManager->xPartition.ulFATBeginLBA + ( ulFATOffset / pxIOManager->xPartition.usBlkSize );
ulFATSectorEntry = ulFATOffset % pxIOManager->xPartition.usBlkSize;
ulLBAAdjust = ulFATSectorEntry / ( ( uint32_t ) pxIOManager->usSectorSize );
ulRelClusterEntry = ulFATSectorEntry % pxIOManager->usSectorSize;
ulFATSector = FF_getRealLBA( pxIOManager, ulFATSector );
ulFATSector += ulLBAAdjust;
}
#if ( ffconfigFAT12_SUPPORT != 0 )
if( ( pxIOManager->xPartition.ucType == FF_T_FAT12 ) &&
( FF_isERR( xError ) == pdFALSE ) &&
( ulRelClusterEntry == ( uint32_t ) ( ( pxIOManager->usSectorSize - 1 ) ) ) )
{
/* Fat Entry SPANS a Sector!
* It has 4 bits on one sector and 8 bits on the other sector.
* Handle this in a separate function prvGetFAT12Entry(). */
ulFATEntry = prvGetFAT12Entry( pxIOManager, &xError, pxFATBuffers, ulFATSector );
if( ( ulCluster & 0x0001 ) != 0 )
{
/* For odd clusters, shift the address 4 bits to the right: */
ulFATEntry = ( ulFATEntry & 0xfff0 ) >> 4;
}
else
{
/* For even clusters, take the lower 12 bits: */
ulFATEntry = ( ulFATEntry & 0x0fff );
}
/* Return ulFATEntry, unless xError contains an error. */
}
else
#endif /* ffconfigFAT12_SUPPORT */
if( FF_isERR( xError ) == pdFALSE )
{
/* Handle FAT16, FAT32, and FAT12 (in case the entry lies on a single sector). */
pxBuffer = prvGetFromFATBuffers( pxIOManager, pxFATBuffers, 0, ulFATSector, &xError, ucMode );
if( FF_isERR( xError ) )
{
xError = FF_GETERROR( xError ) | FF_GETFATENTRY;
}
else
{
switch( pxIOManager->xPartition.ucType )
{
case FF_T_FAT32:
ulFATEntry = FF_getLong( pxBuffer->pucBuffer, ulRelClusterEntry );
/* Clear the top 4 bits. */
ulFATEntry &= 0x0fffffff;
break;
case FF_T_FAT16:
ulFATEntry = ( uint32_t ) FF_getShort( pxBuffer->pucBuffer, ulRelClusterEntry );
break;
#if ( ffconfigFAT12_SUPPORT != 0 )
case FF_T_FAT12:
ulFATEntry = ( uint32_t ) FF_getShort( pxBuffer->pucBuffer, ulRelClusterEntry );
/* Entries are either stored as 4 + 8 bits or as 8 + 4 bits,
* depending on the cluster being odd or even. */
if( ( ulCluster & 0x0001 ) != 0 )
{
/* For odd clusters, shift the address 4 bits to the right: */
ulFATEntry = ( ulFATEntry & 0xfff0 ) >> 4;
}
else
{
/* For even clusters, take the lower 12 bits: */
ulFATEntry = ( ulFATEntry & 0x0fff );
}
break;
#endif /* if ( ffconfigFAT12_SUPPORT != 0 ) */
default:
ulFATEntry = 0;
break;
}
if( pxFATBuffers != NULL )
{
/* Store the buffer. */
pxFATBuffers->pxBuffers[ 0 ] = pxBuffer;
}
else
{
/* Or release it. */
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
}
} /* if( FF_isERR( xError ) == pdFALSE ) */
} /* else Handle FAT16, FAT32, and FAT12 (in case the entry lies on a single sector). */
if( FF_isERR( xError ) )
{
/* The sector address 0 is not meaningful and here it is used as the 'error value'. */
ulFATEntry = 0UL;
}
if( pxError != NULL )
{
*pxError = xError;
}
return ( int32_t ) ulFATEntry;
} /* FF_getFATEntry() */
/*-----------------------------------------------------------*/
/* Write all zero's to all sectors of a given cluster. */
FF_Error_t FF_ClearCluster( FF_IOManager_t * pxIOManager,
uint32_t ulCluster )
{
FF_Error_t xError = FF_ERR_NONE;
FF_Buffer_t * pxBuffer = NULL;
BaseType_t xIndex;
uint32_t ulBaseLBA;
/* Calculate from cluster number to a real block address. */
ulBaseLBA = FF_Cluster2LBA( pxIOManager, ulCluster );
ulBaseLBA = FF_getRealLBA( pxIOManager, ulBaseLBA );
for( xIndex = 0; xIndex < ( BaseType_t ) pxIOManager->xPartition.ulSectorsPerCluster; xIndex++ )
{
if( xIndex == 0 )
{
/* When using the FF_MODE_WR_ONLY flag, the data will not be read from disk.
* Only in the first round a buffer will be claimed. */
pxBuffer = FF_GetBuffer( pxIOManager, ulBaseLBA, FF_MODE_WR_ONLY );
if( pxBuffer == NULL )
{
xError = ( FF_Error_t ) ( FF_ERR_DEVICE_DRIVER_FAILED | FF_CLEARCLUSTER );
break;
}
memset( pxBuffer->pucBuffer, 0x00, pxIOManager->usSectorSize );
}
xError = FF_BlockWrite( pxIOManager, ulBaseLBA + xIndex, 1, pxBuffer->pucBuffer, pdFALSE );
if( FF_isERR( xError ) )
{
break;
}
}
if( pxBuffer != NULL )
{
FF_Error_t xTempError;
/* The contents of the buffer (all zero's) has been written explicitly to disk
* by calling FF_BlockWrite(). Therefore, the bModified should be cleared. */
pxBuffer->bModified = pdFALSE;
/* Releasing the handle will not write anything */
xTempError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
if( FF_isERR( xError ) == pdFALSE )
{
xError = xTempError;
}
}
return xError;
}
/*-----------------------------------------------------------*/
/**
* @private
* @brief Returns the Cluster address of the Cluster number from the beginning of a chain.
*
* @param pxIOManager FF_IOManager_t Object
* @param ulStart Cluster address of the first cluster in the chain.
* @param ulCount Number of Cluster in the chain,
*
*
*
**/
uint32_t FF_TraverseFAT( FF_IOManager_t * pxIOManager,
uint32_t ulStart,
uint32_t ulCount,
FF_Error_t * pxError )
{
FF_Error_t xError = FF_ERR_NONE;
uint32_t ulIndex;
uint32_t ulFatEntry = ulStart;
uint32_t ulCurrentCluster = ulStart;
FF_FATBuffers_t xFATBuffers;
BaseType_t xTakeLock = FF_Has_Lock( pxIOManager, FF_FAT_LOCK ) == pdFALSE;
/* xFATBuffers is nothing more than an array of FF_Buffer_t's.
* One buffer for each FAT copy on disk. */
FF_InitFATBuffers( &xFATBuffers, FF_MODE_READ );
if( xTakeLock )
{
FF_LockFAT( pxIOManager );
}
for( ulIndex = 0; ulIndex < ulCount; ulIndex++ )
{
ulFatEntry = FF_getFATEntry( pxIOManager, ulCurrentCluster, &xError, &xFATBuffers );
if( FF_isERR( xError ) )
{
ulFatEntry = 0;
break;
}
if( FF_isEndOfChain( pxIOManager, ulFatEntry ) )
{
ulFatEntry = ulCurrentCluster;
break;
}
ulCurrentCluster = ulFatEntry;
}
if( xTakeLock )
{
FF_UnlockFAT( pxIOManager );
}
{
FF_Error_t xTempError;
xTempError = FF_ReleaseFATBuffers( pxIOManager, &xFATBuffers );
if( FF_isERR( xError ) == pdFALSE )
{
xError = xTempError;
}
}
*pxError = xError;
return ulFatEntry;
}
/*-----------------------------------------------------------*/
uint32_t FF_FindEndOfChain( FF_IOManager_t * pxIOManager,
uint32_t ulStart,
FF_Error_t * pxError )
{
uint32_t ulFatEntry = ulStart;
FF_Error_t xError;
if( FF_isEndOfChain( pxIOManager, ulStart ) == pdFALSE )
{
/* Traverse FAT for (2^32-1) items/clusters,
* or until end-of-chain is encountered. */
ulFatEntry = FF_TraverseFAT( pxIOManager, ulStart, ~0UL, &xError );
}
else
{
xError = FF_ERR_NONE;
}
*pxError = xError;
return ulFatEntry;
}
/*-----------------------------------------------------------*/
/**
* @private
* @brief Tests if the ulFATEntry is an End of Chain Marker.
*
* @param pxIOManager FF_IOManager_t Object
* @param ulFATEntry The fat entry from the FAT table to be checked.
*
* @return pdTRUE if it is an end of chain, otherwise pdFALSE.
*
**/
BaseType_t FF_isEndOfChain( FF_IOManager_t * pxIOManager,
uint32_t ulFATEntry )
{
BaseType_t xResult = pdFALSE;
if( pxIOManager->xPartition.ucType == FF_T_FAT32 )
{
if( ( ulFATEntry & 0x0fffffff ) >= 0x0ffffff8 )
{
xResult = pdTRUE;
}
}
else if( pxIOManager->xPartition.ucType == FF_T_FAT16 )
{
if( ulFATEntry >= 0x0000fff8 )
{
xResult = pdTRUE;
}
}
else
{
if( ulFATEntry >= 0x00000ff8 )
{
xResult = pdTRUE;
}
}
if( ulFATEntry == 0x00000000 )
{
xResult = pdTRUE; /* Perhaps trying to read a deleted file! */
}
return xResult;
}
/*-----------------------------------------------------------*/
#if ( ffconfigFAT12_SUPPORT != 0 )
static FF_Error_t prvPutFAT12Entry( FF_IOManager_t * pxIOManager,
uint32_t ulCluster,
uint32_t ulValue,
FF_FATBuffers_t * pxFATBuffers,
uint32_t ulFATSector )
{
FF_Buffer_t * pxBuffer = NULL;
/* For FAT12 FAT Table Across sector boundary traversal. */
uint8_t ucBytes[ 2 ];
/* The function result value. */
uint32_t ulFATEntry;
FF_Error_t xError = FF_ERR_NONE;
BaseType_t xIndex;
#if ( ffconfigWRITE_BOTH_FATS != 0 )
const BaseType_t xNumFATs = pxIOManager->xPartition.ucNumFATS;
#else
const BaseType_t xNumFATs = 1;
#endif
/* This routine will only change 12 out of 16 bits.
* Get the current 16-bit value, 4 bits shall be preserved. */
ulFATEntry = prvGetFAT12Entry( pxIOManager, &xError, pxFATBuffers, ulFATSector );
if( FF_isERR( xError ) == pdFALSE )
{
if( ( ulCluster & 0x0001 ) != 0 )
{
ulFATEntry &= 0x000F;
ulValue = ( ulValue << 4 );
ulValue &= 0xFFF0;
}
else
{
ulFATEntry &= 0xF000;
ulValue &= 0x0FFF;
}
ulFATEntry |= ulValue;
/* Write at offset 0 in the array ucBytes. */
FF_putShort( ucBytes, 0, ( uint16_t ) ulFATEntry );
for( xIndex = 0;
xIndex < xNumFATs;
xIndex++, ulFATSector += pxIOManager->xPartition.ulSectorsPerFAT )
{
/* Write the last byte in the first sector. */
pxBuffer = FF_GetBuffer( pxIOManager, ulFATSector, FF_MODE_WRITE );
{
if( pxBuffer == NULL )
{
xError = ( FF_Error_t ) ( FF_ERR_DEVICE_DRIVER_FAILED | FF_PUTFATENTRY );
break;
}
FF_putChar( pxBuffer->pucBuffer, ( uint16_t ) ( pxIOManager->usSectorSize - 1 ), ucBytes[ 0 ] );
}
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
if( FF_isERR( xError ) )
{
break;
}
/* Write the first byte in the subsequent sector. */
pxBuffer = FF_GetBuffer( pxIOManager, ulFATSector + 1, FF_MODE_WRITE );
{
if( pxBuffer == NULL )
{
xError = ( FF_Error_t ) ( FF_ERR_DEVICE_DRIVER_FAILED | FF_PUTFATENTRY );
break;
}
FF_putChar( pxBuffer->pucBuffer, 0x0000, ucBytes[ 1 ] );
}
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
if( FF_isERR( xError ) )
{
break;
}
} /* for ( xIndex = 0; xIndex < xNumFATs; xIndex++ ) */
}
return xError;
}
#endif /* if ( ffconfigFAT12_SUPPORT != 0 ) */
/**
* @private
* @brief Writes a new Entry to the FAT Tables.
*
* @param pxIOManager IOMAN object.
* @param ulCluster Cluster Number to be modified.
* @param ulValue The value to store.
**/
FF_Error_t FF_putFATEntry( FF_IOManager_t * pxIOManager,
uint32_t ulCluster,
uint32_t ulValue,
FF_FATBuffers_t * pxFATBuffers )
{
FF_Buffer_t * pxBuffer;
uint32_t ulFATOffset;
uint32_t ulFATSector = 0;
uint32_t ulFATSectorEntry;
uint32_t ulFATEntry;
uint32_t ulLBAAdjust;
uint32_t ulRelClusterEntry = 0;
BaseType_t xIndex;
FF_Error_t xError = FF_ERR_NONE;
#if ( ffconfigWRITE_BOTH_FATS != 0 )
const BaseType_t xNumFATs = pxIOManager->xPartition.ucNumFATS;
#else
const BaseType_t xNumFATs = 1;
#endif
FF_Assert_Lock( pxIOManager, FF_FAT_LOCK );
/* Avoid corrupting the disk. */
if( ( ulCluster == 0ul ) || ( ulCluster >= pxIOManager->xPartition.ulNumClusters ) )
{
/* find a more specific error code. */
xError = ( FF_Error_t ) ( FF_ERR_IOMAN_NOT_ENOUGH_FREE_SPACE | FF_PUTFATENTRY );
}
else
{
if( pxIOManager->xPartition.ucType == FF_T_FAT32 )
{
ulFATOffset = ulCluster * 4;
}
else if( pxIOManager->xPartition.ucType == FF_T_FAT16 )
{
ulFATOffset = ulCluster * 2;
}
else /* pxIOManager->xPartition.ucType == FF_T_FAT12 */
{
ulFATOffset = ulCluster + ( ulCluster / 2 );
}
ulFATSector = pxIOManager->xPartition.ulFATBeginLBA + ( ulFATOffset / pxIOManager->xPartition.usBlkSize );
ulFATSectorEntry = ulFATOffset % pxIOManager->xPartition.usBlkSize;
ulLBAAdjust = ulFATSectorEntry / ( ( uint32_t ) pxIOManager->usSectorSize );
ulRelClusterEntry = ulFATSectorEntry % pxIOManager->usSectorSize;
ulFATSector = FF_getRealLBA( pxIOManager, ulFATSector );
ulFATSector += ulLBAAdjust;
}
#if ( ffconfigFAT12_SUPPORT != 0 )
if( ( pxIOManager->xPartition.ucType == FF_T_FAT12 ) &&
( FF_isERR( xError ) == pdFALSE ) &&
( ulRelClusterEntry == ( uint32_t ) ( ( pxIOManager->usSectorSize - 1 ) ) ) )
{
/* The special case in which one FAT12 entries is divided over 2 sectors.
* Treat this in a separate function. */
xError = prvPutFAT12Entry( pxIOManager, ulCluster, ulValue, pxFATBuffers, ulFATSector );
/* Return xError. */
}
else
#endif /* ffconfigFAT12_SUPPORT */
if( FF_isERR( xError ) == pdFALSE )
{
/* Handle FAT16, FAT32, and FAT12 (in case the entry lies on a single sector). */
for( xIndex = 0;
xIndex < xNumFATs;
xIndex++, ulFATSector += pxIOManager->xPartition.ulSectorsPerFAT )
{
pxBuffer = prvGetFromFATBuffers( pxIOManager, pxFATBuffers, xIndex, ulFATSector, &xError, FF_MODE_WRITE );
if( FF_isERR( xError ) )
{
xError = FF_GETERROR( xError ) | FF_PUTFATENTRY;
break;
}
if( pxIOManager->xPartition.ucType == FF_T_FAT32 )
{
/* Clear the top 4 bits. */
ulValue &= 0x0fffffff;
FF_putLong( pxBuffer->pucBuffer, ulRelClusterEntry, ulValue );
}
else if( pxIOManager->xPartition.ucType == FF_T_FAT16 )
{
FF_putShort( pxBuffer->pucBuffer, ulRelClusterEntry, ( uint16_t ) ulValue );
}
else
{
ulFATEntry = ( uint32_t ) FF_getShort( pxBuffer->pucBuffer, ulRelClusterEntry );
if( ( ulCluster & 0x0001 ) != 0 )
{
ulFATEntry &= 0x000F;
ulValue = ( ulValue << 4 );
ulValue &= 0xFFF0;
}
else
{
ulFATEntry &= 0xF000;
ulValue &= 0x0FFF;
}
FF_putShort( pxBuffer->pucBuffer, ulRelClusterEntry, ( uint16_t ) ( ulFATEntry | ulValue ) );
}
if( ( xIndex < ffconfigBUF_STORE_COUNT ) && ( pxFATBuffers != NULL ) )
{
/* Store it for later use. */
pxFATBuffers->pxBuffers[ xIndex ] = pxBuffer;
pxFATBuffers->ucMode = FF_MODE_WRITE;
}
else
{
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
if( FF_isERR( xError ) )
{
break;
}
}