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ff_ioman.c
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ff_ioman.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_ioman.c
* @ingroup IOMAN
*
* @defgroup IOMAN I/O Manager
* @brief Handles IO buffers for FreeRTOS+FAT safely.
*
* Provides a simple static interface to the rest of FreeRTOS+FAT to manage
* buffers. It also defines the public interfaces for Creating and
* Destroying a FreeRTOS+FAT IO object.
**/
#include <time.h>
#include <string.h>
#include "ff_headers.h"
#define FAT16_SECTOR_COUNT_4085 4085
#define FAT32_SECTOR_COUNT_65525 65525 /* 65536 clusters */
/* Some values and offsets describing the special sector FS INFO: */
#define FS_INFO_SIGNATURE1_0x41615252 0x41615252UL
#define FS_INFO_SIGNATURE2_0x61417272 0x61417272UL
#define FS_INFO_OFFSET_SIGNATURE1_000 0
#define FS_INFO_OFFSET_SIGNATURE2_484 484
#define FS_INFO_OFFSET_FREE_COUNT_488 488
#define FS_INFO_OFFSET_FREE_CLUSTER_492 492
/* Inspect the PBR (Partition Boot Record) to determine the type of FAT */
static FF_Error_t prvDetermineFatType( FF_IOManager_t * pxIOManager );
/* Check if a given ID introduces an extended partition. */
static BaseType_t prvIsExtendedPartition( uint8_t ucPartitionID );
/* Return pdTRUE if the media byte in an MBR is valid. */
static BaseType_t prvIsValidMedia( uint8_t media );
/* Read the MBR to see what extended partitions have been defined.
* Definitions of extended partitions may be chained.
* Walk down the chain to find all extended partitions. */
static FF_Error_t FF_ParseExtended( FF_IOManager_t * pxIOManager,
uint32_t ulFirstSector,
uint32_t ulFirstSize,
FF_SPartFound_t * pPartsFound );
static FF_Error_t FF_GetEfiPartitionEntry( FF_IOManager_t * pxIOManager,
uint32_t ulPartitionNumber );
static BaseType_t prvHasActiveHandles( FF_IOManager_t * pxIOManager );
/**
* @brief Creates an FF_IOManager_t object, to initialise FreeRTOS+FAT
*
* @param pxParameters The Creation parameters to create the IO manager with
* @param pError Pointer to a signed byte for error checking. Can be NULL if not required.
* To be checked when a NULL pointer is returned.
*
* @return Returns a pointer to an FF_IOManager_t type object. NULL on xError, check the contents of
* pError
**/
FF_IOManager_t * FF_CreateIOManager( FF_CreationParameters_t * pxParameters,
FF_Error_t * pError )
{
FF_IOManager_t * pxIOManager = NULL;
FF_Error_t xError;
uint32_t ulCacheSize = pxParameters->ulMemorySize;
uint32_t usSectorSize = ( uint32_t ) pxParameters->ulSectorSize;
/* Normally:
* ulSectorSize = 512
* ulCacheSize = N x ulSectorSize. */
if( ( ( usSectorSize % 512 ) != 0 ) || ( usSectorSize == 0 ) )
{
/* ulSectorSize Size not a multiple of 512 or it is zero*/
xError = FF_createERR( FF_ERR_IOMAN_BAD_BLKSIZE, FF_CREATEIOMAN );
}
else if( ( ( ulCacheSize % ( uint32_t ) usSectorSize ) != 0 ) || ( ulCacheSize == 0 ) ||
( ulCacheSize == ( uint32_t ) usSectorSize ) )
{
/* The size of the caching memory (ulCacheSize) must now be atleast 2 * ulSectorSize (or a deadlock will occur). */
xError = FF_createERR( FF_ERR_IOMAN_BAD_MEMSIZE, FF_CREATEIOMAN );
}
else
{
pxIOManager = ( FF_IOManager_t * ) ffconfigMALLOC( sizeof( FF_IOManager_t ) );
/* Ensure malloc() succeeded. */
if( pxIOManager != NULL )
{
/* Use memset() to clear every single bit. */
memset( pxIOManager, '\0', sizeof( FF_IOManager_t ) );
if( FF_CreateEvents( pxIOManager ) != pdFALSE )
{
xError = FF_ERR_NONE;
}
else
{
/* xEventGroupCreate() probably failed. */
xError = FF_createERR( FF_ERR_NOT_ENOUGH_MEMORY, FF_CREATEIOMAN );
}
}
else
{
/* ffconfigMALLOC() failed. */
xError = FF_createERR( FF_ERR_NOT_ENOUGH_MEMORY, FF_CREATEIOMAN );
}
}
if( FF_isERR( xError ) == pdFALSE )
{
/* pxIOManager is created, FF_CreateEvents() succeeded. */
if( pxParameters->pucCacheMemory != NULL )
{
/* The caller has provided a piece of memory, use it. */
pxIOManager->pucCacheMem = pxParameters->pucCacheMemory;
}
else
{
/* No cache buffer provided, call malloc(). */
pxIOManager->pucCacheMem = ( uint8_t * ) ffconfigMALLOC( ulCacheSize );
if( pxIOManager->pucCacheMem != NULL )
{
/* Indicate that malloc() was used for pucCacheMem. */
pxIOManager->ucFlags |= FF_IOMAN_ALLOC_BUFFERS;
}
else
{
xError = FF_createERR( FF_ERR_NOT_ENOUGH_MEMORY, FF_CREATEIOMAN );
}
}
if( pxIOManager->pucCacheMem != NULL )
{
memset( pxIOManager->pucCacheMem, '\0', ulCacheSize );
}
}
if( FF_isERR( xError ) == pdFALSE )
{
pxIOManager->usSectorSize = ( uint16_t ) usSectorSize;
pxIOManager->usCacheSize = ( uint16_t ) ( ulCacheSize / ( uint32_t ) usSectorSize );
/* Malloc() memory for buffer objects. FreeRTOS+FAT never refers to a
* buffer directly but uses buffer objects instead. Allows for thread
* safety. */
pxIOManager->pxBuffers = ( FF_Buffer_t * ) ffconfigMALLOC( sizeof( FF_Buffer_t ) * pxIOManager->usCacheSize );
if( pxIOManager->pxBuffers != NULL )
{
/* From now on a call to FF_IOMAN_InitBufferDescriptors will clear
* pxBuffers. */
pxIOManager->ucFlags |= FF_IOMAN_ALLOC_BUFDESCR;
FF_IOMAN_InitBufferDescriptors( pxIOManager );
/* Finally store the semaphore for Buffer Description modifications. */
pxIOManager->pvSemaphore = pxParameters->pvSemaphore;
#if ( ffconfigPROTECT_FF_FOPEN_WITH_SEMAPHORE == 1 )
pxIOManager->pvSemaphoreOpen = xSemaphoreCreateRecursiveMutex();
if( pxIOManager->pvSemaphoreOpen == NULL )
{
/* Tell the user that there was not enough memory. */
xError = FF_createERR( FF_ERR_NOT_ENOUGH_MEMORY, FF_CREATEIOMAN );
}
else
#endif /* ffconfigPROTECT_FF_FOPEN_WITH_SEMAPHORE */
{
if( pxParameters->xBlockDeviceIsReentrant != pdFALSE )
{
pxIOManager->ucFlags |= FF_IOMAN_BLOCK_DEVICE_IS_REENTRANT;
}
pxIOManager->xBlkDevice.fnpReadBlocks = pxParameters->fnReadBlocks;
pxIOManager->xBlkDevice.fnpWriteBlocks = pxParameters->fnWriteBlocks;
pxIOManager->xBlkDevice.pxDisk = pxParameters->pxDisk;
}
}
else
{
xError = FF_createERR( FF_ERR_NOT_ENOUGH_MEMORY, FF_CREATEIOMAN );
}
}
if( FF_isERR( xError ) )
{
if( pxIOManager != NULL )
{
FF_DeleteIOManager( pxIOManager );
pxIOManager = NULL;
}
}
if( pError != NULL )
{
*pError = xError;
}
return pxIOManager;
} /* FF_CreateIOManager() */
/*-----------------------------------------------------------*/
/**
* @brief Destroys an FF_IOManager_t object, and frees all assigned memory.
*
* @param pxIOManager Pointer to an FF_IOManager_t object, as returned from FF_CreateIOManager.
*
* @return FF_ERR_NONE on success, or a documented error code on failure. (FF_ERR_NULL_POINTER)
*
**/
FF_Error_t FF_DeleteIOManager( FF_IOManager_t * pxIOManager )
{
FF_Error_t xError;
/* Ensure no NULL pointer was provided. */
if( pxIOManager == NULL )
{
xError = FF_createERR( FF_ERR_NULL_POINTER, FF_DESTROYIOMAN );
}
else
{
xError = FF_ERR_NONE;
/* Ensure pxBuffers pointer was allocated. */
if( ( pxIOManager->ucFlags & FF_IOMAN_ALLOC_BUFDESCR ) != 0 )
{
ffconfigFREE( pxIOManager->pxBuffers );
}
/* Ensure pucCacheMem pointer was allocated. */
if( ( pxIOManager->ucFlags & FF_IOMAN_ALLOC_BUFFERS ) != 0 )
{
ffconfigFREE( pxIOManager->pucCacheMem );
}
#if ( ffconfigPROTECT_FF_FOPEN_WITH_SEMAPHORE == 1 )
{
if( pxIOManager->pvSemaphoreOpen != NULL )
{
vSemaphoreDelete( pxIOManager->pvSemaphoreOpen );
}
}
#endif
/* Delete the event group object within the IO manager before deleting
* the manager. */
FF_DeleteEvents( pxIOManager );
/* Finally free the FF_IOManager_t object. */
ffconfigFREE( pxIOManager );
}
return xError;
} /* FF_DeleteIOManager() */
/*-----------------------------------------------------------*/
/**
* @brief Initialises Buffer Descriptions as part of the FF_IOManager_t object initialisation.
*
* @param pxIOManager IOMAN Object.
*
**/
void FF_IOMAN_InitBufferDescriptors( FF_IOManager_t * pxIOManager )
{
uint8_t * pucBuffer = pxIOManager->pucCacheMem;
FF_Buffer_t * pxBuffer = pxIOManager->pxBuffers;
FF_Buffer_t * pxLastBuffer = pxBuffer + pxIOManager->usCacheSize;
/* Clear the contents of the buffer descriptors. */
memset( ( void * ) pxBuffer, '\0', sizeof( FF_Buffer_t ) * pxIOManager->usCacheSize );
while( pxBuffer < pxLastBuffer )
{
pxBuffer->pucBuffer = pucBuffer;
pxBuffer++;
pucBuffer += pxIOManager->usSectorSize;
}
} /* FF_IOMAN_InitBufferDescriptors() */
/*-----------------------------------------------------------*/
/**
* @brief Flushes all Write cache buffers with no active Handles.
*
* @param pxIOManager IOMAN Object.
*
* @return FF_ERR_NONE on Success.
**/
FF_Error_t FF_FlushCache( FF_IOManager_t * pxIOManager )
{
BaseType_t xIndex, xIndex2;
FF_Error_t xError;
if( pxIOManager == NULL )
{
xError = FF_createERR( FF_ERR_NULL_POINTER, FF_FLUSHCACHE );
}
else
{
xError = FF_ERR_NONE;
FF_PendSemaphore( pxIOManager->pvSemaphore );
{
for( xIndex = 0; xIndex < pxIOManager->usCacheSize; xIndex++ )
{
/* If a buffers has no users and if it has been modified... */
if( ( pxIOManager->pxBuffers[ xIndex ].usNumHandles == 0 ) && ( pxIOManager->pxBuffers[ xIndex ].bModified == pdTRUE ) )
{
/* The buffer may be flushed to disk. */
FF_BlockWrite( pxIOManager, pxIOManager->pxBuffers[ xIndex ].ulSector, 1, pxIOManager->pxBuffers[ xIndex ].pucBuffer, pdTRUE );
/* Buffer has now been flushed, mark it as a read buffer and unmodified. */
pxIOManager->pxBuffers[ xIndex ].ucMode = FF_MODE_READ;
pxIOManager->pxBuffers[ xIndex ].bModified = pdFALSE;
/* Search for other buffers that used this sector, and mark them as modified
* So that further requests will result in the new sector being fetched. */
for( xIndex2 = 0; xIndex2 < pxIOManager->usCacheSize; xIndex2++ )
{
if( ( xIndex != xIndex2 ) &&
( pxIOManager->pxBuffers[ xIndex2 ].ulSector == pxIOManager->pxBuffers[ xIndex ].ulSector ) &&
( pxIOManager->pxBuffers[ xIndex2 ].ucMode == FF_MODE_READ ) )
{
pxIOManager->pxBuffers[ xIndex2 ].bModified = pdTRUE;
}
}
}
}
}
if( ( pxIOManager->xBlkDevice.pxDisk != NULL ) &&
( pxIOManager->xBlkDevice.pxDisk->fnFlushApplicationHook != NULL ) )
{
/* Let the low-level driver also flush data.
* See comments in ff_ioman.h. */
pxIOManager->xBlkDevice.pxDisk->fnFlushApplicationHook( pxIOManager->xBlkDevice.pxDisk );
}
FF_ReleaseSemaphore( pxIOManager->pvSemaphore );
}
return xError;
} /* FF_FlushCache() */
/*-----------------------------------------------------------*/
/*
* A new version of FF_GetBuffer() with a simple mechanism for timeout
*/
#define FF_GETBUFFER_SLEEP_TIME_MS 10
#define FF_GETBUFFER_WAIT_TIME_MS ( 20000 / FF_GETBUFFER_SLEEP_TIME_MS )
FF_Buffer_t * FF_GetBuffer( FF_IOManager_t * pxIOManager,
uint32_t ulSector,
uint8_t ucMode )
{
FF_Buffer_t * pxBuffer;
/* Least Recently Used Buffer */
FF_Buffer_t * pxRLUBuffer;
FF_Buffer_t * pxMatchingBuffer = NULL;
int32_t lRetVal;
BaseType_t xLoopCount = FF_GETBUFFER_WAIT_TIME_MS;
const FF_Buffer_t * pxLastBuffer = &( pxIOManager->pxBuffers[ pxIOManager->usCacheSize ] );
/* 'pxIOManager->usCacheSize' is bigger than zero and it is a multiple of ulSectorSize. */
while( pxMatchingBuffer == NULL )
{
xLoopCount--;
if( xLoopCount == 0 )
{
break;
}
FF_PendSemaphore( pxIOManager->pvSemaphore );
for( pxBuffer = pxIOManager->pxBuffers; pxBuffer < pxLastBuffer; pxBuffer++ )
{
if( ( pxBuffer->ulSector == ulSector ) && ( pxBuffer->bValid ) )
{
pxMatchingBuffer = pxBuffer;
/* Don't look further if you found a perfect match. */
break;
}
}
if( pxMatchingBuffer != NULL )
{
/* A Match was found process! */
if( ( ucMode == FF_MODE_READ ) && ( pxMatchingBuffer->ucMode == FF_MODE_READ ) )
{
pxMatchingBuffer->usNumHandles += 1;
pxMatchingBuffer->usPersistence += 1;
break;
}
if( pxMatchingBuffer->usNumHandles == 0 )
{
/* Copy the read & write flags. */
pxMatchingBuffer->ucMode = ( ucMode & FF_MODE_RD_WR );
if( ( ucMode & FF_MODE_WRITE ) != 0 )
{
/* This buffer has no attached handles. */
pxMatchingBuffer->bModified = pdTRUE;
}
pxMatchingBuffer->usNumHandles = 1;
pxMatchingBuffer->usPersistence += 1;
break;
}
/* Sector is already in use in a different mode, keep yielding until its available! */
pxMatchingBuffer = NULL;
}
else
{
/* There is no valid buffer now for the desired sector.
* Find a free buffer and use it for that sector. */
pxRLUBuffer = NULL;
for( pxBuffer = pxIOManager->pxBuffers; pxBuffer < pxLastBuffer; pxBuffer++ )
{
if( pxBuffer->usNumHandles != 0 )
{
continue; /* Occupied */
}
pxBuffer->ulLRU += 1;
if( ( pxRLUBuffer == NULL ) ||
( pxBuffer->ulLRU > pxRLUBuffer->ulLRU ) ||
( ( pxBuffer->ulLRU == pxRLUBuffer->ulLRU ) && ( pxBuffer->usPersistence > pxRLUBuffer->usPersistence ) ) )
{
pxRLUBuffer = pxBuffer;
}
}
/* A free buffer with the highest value of 'ulLRU' was found: */
if( pxRLUBuffer != NULL )
{
/* Process the suitable candidate. */
if( pxRLUBuffer->bModified == pdTRUE )
{
/* Along with the pdTRUE parameter to indicate semaphore has been claimed already. */
lRetVal = FF_BlockWrite( pxIOManager, pxRLUBuffer->ulSector, 1, pxRLUBuffer->pucBuffer, pdTRUE );
if( lRetVal < 0 )
{
/* NULL will be returned because 'pxMatchingBuffer' is still NULL. */
break;
}
}
if( ucMode == FF_MODE_WR_ONLY )
{
memset( pxRLUBuffer->pucBuffer, '\0', pxIOManager->usSectorSize );
}
else
{
lRetVal = FF_BlockRead( pxIOManager, ulSector, 1, pxRLUBuffer->pucBuffer, pdTRUE );
if( lRetVal < 0 )
{
/* 'pxMatchingBuffer' is NULL. */
break;
}
}
pxRLUBuffer->ucMode = ( ucMode & FF_MODE_RD_WR );
pxRLUBuffer->usPersistence = 1;
pxRLUBuffer->ulLRU = 0;
pxRLUBuffer->usNumHandles = 1;
pxRLUBuffer->ulSector = ulSector;
pxRLUBuffer->bModified = ( ucMode & FF_MODE_WRITE ) != 0;
pxRLUBuffer->bValid = pdTRUE;
pxMatchingBuffer = pxRLUBuffer;
break;
} /* if( pxRLUBuffer != NULL ) */
} /* else ( pxMatchingBuffer == NULL ) */
FF_ReleaseSemaphore( pxIOManager->pvSemaphore );
/* Better to go asleep to give low-priority task a chance to release buffer(s). */
FF_BufferWait( pxIOManager, FF_GETBUFFER_SLEEP_TIME_MS );
} /* while( pxMatchingBuffer == NULL ) */
if( xLoopCount > 0 )
{
/* If xLoopCount is 0 here, the semaphore was not taken. */
FF_ReleaseSemaphore( pxIOManager->pvSemaphore );
}
if( pxMatchingBuffer == NULL )
{
FF_PRINTF( "FF_GetBuffer[0x%X]: failed mode 0x%X\n", ( unsigned ) ulSector, ( unsigned ) ucMode );
}
return pxMatchingBuffer; /* Return the Matched Buffer! */
} /* FF_GetBuffer() */
/*-----------------------------------------------------------*/
/**
* @brief Releases a buffer resource.
*
* @param pxIOManager Pointer to an FF_IOManager_t object.
* @param pxBuffer Pointer to an FF_Buffer_t object.
*
**/
FF_Error_t FF_ReleaseBuffer( FF_IOManager_t * pxIOManager,
FF_Buffer_t * pxBuffer )
{
FF_Error_t xError = FF_ERR_NONE;
/* Protect description changes with a semaphore. */
FF_PendSemaphore( pxIOManager->pvSemaphore );
{
#if ( ffconfigCACHE_WRITE_THROUGH != 0 )
if( pxBuffer->bModified == pdTRUE )
{
xError = FF_BlockWrite( pxIOManager, pxBuffer->ulSector, 1, pxBuffer->pucBuffer, pdTRUE );
if( FF_isERR( xError ) == pdFALSE )
{
/* Ensure if an error occurs its still possible to write the block again. */
pxBuffer->bModified = pdFALSE;
}
}
#endif /* if ( ffconfigCACHE_WRITE_THROUGH != 0 ) */
configASSERT( pxBuffer->usNumHandles != 0 );
if( pxBuffer->usNumHandles != 0 )
{
pxBuffer->usNumHandles--;
}
else
{
/*printf ("FF_ReleaseBuffer: buffer not claimed\n"); */
}
}
FF_ReleaseSemaphore( pxIOManager->pvSemaphore );
/* Notify tasks which may be waiting in FF_GetBuffer() */
FF_BufferProceed( pxIOManager );
return xError;
} /* FF_ReleaseBuffer() */
/*-----------------------------------------------------------*/
/* New Interface for FreeRTOS+FAT to read blocks. */
int32_t FF_BlockRead( FF_IOManager_t * pxIOManager,
uint32_t ulSectorLBA,
uint32_t ulNumSectors,
void * pxBuffer,
BaseType_t xSemLocked )
{
int32_t slRetVal = 0;
if( pxIOManager->xPartition.ulTotalSectors != 0ul )
{
/* At some point while formatting a partition, ulTotalSectors might be unknown.
* In that case this test will be skipped. */
if( ( ulSectorLBA + ulNumSectors ) > ( pxIOManager->xPartition.ulTotalSectors + pxIOManager->xPartition.ulBeginLBA ) )
{
slRetVal = FF_createERR( FF_ERR_IOMAN_OUT_OF_BOUNDS_READ, FF_BLOCKREAD );
}
}
if( ( slRetVal == 0ul ) && ( pxIOManager->xBlkDevice.fnpReadBlocks != NULL ) )
{
do
{
/* Make sure we don't execute a NULL. */
if( ( xSemLocked == pdFALSE ) &&
( ( pxIOManager->ucFlags & FF_IOMAN_BLOCK_DEVICE_IS_REENTRANT ) == pdFALSE ) )
{
FF_PendSemaphore( pxIOManager->pvSemaphore );
}
slRetVal = pxIOManager->xBlkDevice.fnpReadBlocks( pxBuffer, ulSectorLBA, ulNumSectors, pxIOManager->xBlkDevice.pxDisk );
if( ( xSemLocked == pdFALSE ) &&
( ( pxIOManager->ucFlags & FF_IOMAN_BLOCK_DEVICE_IS_REENTRANT ) == pdFALSE ) )
{
FF_ReleaseSemaphore( pxIOManager->pvSemaphore );
}
/* Do not use 'FF_GETERROR()' here because FF_ERR_DRIVER_BUSY
* is a full 32-bit error code, containing module, function and
* the actual error code. See 'ff_error.h' for definitions. */
if( slRetVal != ( int32_t ) FF_ERR_DRIVER_BUSY )
{
break;
}
FF_Sleep( ffconfigDRIVER_BUSY_SLEEP_MS );
} while( pdTRUE );
}
return slRetVal;
} /* FF_BlockRead() */
/*-----------------------------------------------------------*/
int32_t FF_BlockWrite( FF_IOManager_t * pxIOManager,
uint32_t ulSectorLBA,
uint32_t ulNumSectors,
void * pxBuffer,
BaseType_t xSemLocked )
{
int32_t slRetVal = 0;
if( pxIOManager->xPartition.ulTotalSectors != 0 )
{
/* At some point while formatting a partition, ulTotalSectors might be unknown.
* In that case this test will be skipped. */
if( ( ulSectorLBA + ulNumSectors ) > ( pxIOManager->xPartition.ulTotalSectors + pxIOManager->xPartition.ulBeginLBA ) )
{
slRetVal = FF_createERR( FF_ERR_IOMAN_OUT_OF_BOUNDS_WRITE, FF_BLOCKWRITE );
}
}
if( ( slRetVal == 0ul ) && ( pxIOManager->xBlkDevice.fnpWriteBlocks != NULL ) )
{
do
{ /* Make sure we don't execute a NULL. */
if( ( xSemLocked == pdFALSE ) &&
( ( pxIOManager->ucFlags & FF_IOMAN_BLOCK_DEVICE_IS_REENTRANT ) == pdFALSE ) )
{
FF_PendSemaphore( pxIOManager->pvSemaphore );
}
slRetVal = pxIOManager->xBlkDevice.fnpWriteBlocks( pxBuffer, ulSectorLBA, ulNumSectors, pxIOManager->xBlkDevice.pxDisk );
if( ( xSemLocked == pdFALSE ) &&
( ( pxIOManager->ucFlags & FF_IOMAN_BLOCK_DEVICE_IS_REENTRANT ) == pdFALSE ) )
{
FF_ReleaseSemaphore( pxIOManager->pvSemaphore );
}
/* Do not use 'FF_GETERROR()' here because FF_ERR_DRIVER_BUSY
* is a full 32-bit error code, containing module, function and
* the actual error code. See 'ff_error.h' for definitions. */
if( slRetVal != ( int32_t ) FF_ERR_DRIVER_BUSY )
{
break;
}
FF_Sleep( ffconfigDRIVER_BUSY_SLEEP_MS );
} while( pdTRUE );
}
return slRetVal;
} /* FF_BlockWrite() */
/*-----------------------------------------------------------*/
/*
* This global variable is a kind of expert option:
* It may be set to one of these values: FF_T_FAT[12,16,32]
* just to force the driver to assume a certain FAT type.
*/
static uint8_t ucAssumeFATType = 0;
/* The history of FAT types:
* The Microsoft documents says that the actual type: FAT-12, FAT-16 and FAT-32
* of a partition can be found by looking at the total number of data clusters:
*
* if( clusters < 4085 )
* Assume FAT-12
* else if( clusters < 65525 )
* Assume FAT-16
* else
* Assume FAT-32
*
* In practice however, this does not always seem to be a correct assumption.
*
* The end-of-chain value in the FAT table may also help to determine the
* correct FAT-type:
*
* ulFirstCluster = the first 32-bit of the FAT.
* FAT-12: endOfChain == 0x00000FF8 - 12 bits
* FAT-16: endOfChain == 0x0000FFF8 - 16 bits
* FAT-32: endOfChain == 0x0FFFFFF8 - 32 bits
*/
static FF_Error_t prvDetermineFatType( FF_IOManager_t * pxIOManager )
{
FF_Partition_t * pxPartition;
FF_Buffer_t * pxBuffer;
/* The first 32-bits of the FAT. */
uint32_t ulFirstCluster = 0U;
FF_Error_t xError = FF_ERR_NONE;
pxPartition = &( pxIOManager->xPartition );
if( ucAssumeFATType != 0 )
{
switch( ucAssumeFATType )
{
case FF_T_FAT12:
case FF_T_FAT16:
case FF_T_FAT32:
pxPartition->ucType = ucAssumeFATType;
break;
default:
/* An invalid value will be ignored, and the FAT type is determined dynamically. */
ucAssumeFATType = 0;
break;
}
xError = FF_ERR_NONE;
}
/* Test again, the value may have become zero now: */
if( ucAssumeFATType == 0 )
{
pxBuffer = FF_GetBuffer( pxIOManager, pxIOManager->xPartition.ulFATBeginLBA, FF_MODE_READ );
if( pxBuffer == NULL )
{
xError = FF_createERR( FF_ERR_DEVICE_DRIVER_FAILED, FF_DETERMINEFATTYPE );
}
else
{
/* Read the first 4 bytes at offset 0. */
ulFirstCluster = FF_getLong( pxBuffer->pucBuffer, 0U );
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
}
}
if( ( ucAssumeFATType == 0 ) && ( FF_isERR( xError ) == pdFALSE ) )
{
#if ( ffconfigFAT12_SUPPORT != 0 )
if( pxPartition->ulNumClusters < FAT16_SECTOR_COUNT_4085 )
{
/* FAT12 */
pxPartition->ucType = FF_T_FAT12;
#if ( ffconfigFAT_CHECK != 0 )
/* Keep bits 4..11 */
/* MS-DOS/PC DOS 3.3 and higher treats a value of 0xFF0 on FAT12.
* See https://en.wikipedia.org/wiki/Design_of_the_FAT_file_system
*/
ulFirstCluster &= 0xFF0U;
if( ulFirstCluster != 0xFF0U )
{
xError = FF_createERR( FF_ERR_IOMAN_NOT_FAT_FORMATTED, FF_DETERMINEFATTYPE );
FF_PRINTF( "FAT_CHECK: FAT12 Partition has unexpected FAT data %04lX\n",
ulFirstCluster );
}
else
#endif /* ffconfigFAT_CHECK */
{
/* FAT12 entry OK. */
xError = FF_ERR_NONE;
}
}
else
#endif /* ffconfigFAT12_SUPPORT */
if( pxPartition->ulNumClusters < FAT32_SECTOR_COUNT_65525 )
{
/* FAT 16 */
pxPartition->ucType = FF_T_FAT16;
#if ( ffconfigFAT_CHECK != 0 )
{
/* Keep bits 4..15 */
ulFirstCluster &= 0xFFF8U;
if( ulFirstCluster == 0xFFF8U )
{
/* FAT16 entry OK. */
xError = FF_ERR_NONE;
}
else
{
if( ( ulFirstCluster & 0xFF8U ) == 0xFF8U )
{
FF_PRINTF( "FAT_CHECK: FAT16 Part at %lu is probably a FAT12\n", pxIOManager->xPartition.ulFATBeginLBA );
}
else
{
FF_PRINTF( "FAT_CHECK: FAT16 Partition has unexpected FAT data %08lX\n",
ulFirstCluster );
}
xError = FF_createERR( FF_ERR_IOMAN_INVALID_FORMAT, FF_DETERMINEFATTYPE );
}
}
#endif /* ffconfigFAT_CHECK */
}
else
{
/* FAT 32! */
pxPartition->ucType = FF_T_FAT32;
#if ( ffconfigFAT_CHECK != 0 )
/* Keep bits 4..27 */
ulFirstCluster &= 0x0FFFFFF8UL;
if( ulFirstCluster != 0x0FFFFFF8UL )
{
FF_PRINTF( "FAT_CHECK: FAT32 Partition at %lu has unexpected FAT data %08lX\n",
pxIOManager->xPartition.ulFATBeginLBA, ulFirstCluster );
xError = FF_ERR_IOMAN_NOT_FAT_FORMATTED;
}
else
#endif /* ffconfigFAT_CHECK */
{
/* FAT32 entry OK. */
xError = FF_ERR_NONE;
}
}
}
return xError;
} /* prvDetermineFatType() */
/*-----------------------------------------------------------*/
/* Check if ucPartitionID introduces an extended partition. */
static BaseType_t prvIsExtendedPartition( uint8_t ucPartitionID )
{
BaseType_t xResult;
if( ( ucPartitionID == FF_DOS_EXT_PART ) ||
( ucPartitionID == FF_WIN98_EXT_PART ) ||
( ucPartitionID == FF_LINUX_EXT_PART ) )
{
xResult = pdTRUE;
}
else
{
xResult = pdFALSE;
}
return xResult;
} /* prvIsExtendedPartition() */
/*-----------------------------------------------------------*/
/* Check if the media byte in an MBR is valid */
static BaseType_t prvIsValidMedia( uint8_t media )
{
BaseType_t xResult;
/*
* 0xF8 is the standard value for fixed (non-removable) media. For
* removable media, 0xF0 is frequently used. The legal values for this
* field are 0xF0, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, and
* 0xFF. The only other important point is that whatever value is put
* in here must also be put in the low byte of the FAT[0] entry. This
* dates back to the old MS-DOS 1.x media determination noted
* earlier and is no longer usually used for anything.
*/
if( ( 0xf8 <= media ) || ( media == 0xf0 ) )
{
xResult = pdTRUE;
}
else
{
xResult = pdFALSE;
}
return xResult;
} /* prvIsValidMedia() */
/*-----------------------------------------------------------*/
void FF_ReadParts( uint8_t * pucBuffer,
FF_Part_t * pxParts )
{
BaseType_t xPartNr;
UBaseType_t uxOffset = FF_FAT_PTBL;
/* pxParts is expected to be declared as an array of 4 elements:
* FF_Part_t pxParts[4];
* FF_ReadParts( pxBuffer->pucBuffer, pxParts );
*/
for( xPartNr = 0; xPartNr < 4; xPartNr++, uxOffset += 16, pxParts++ )
{
pxParts->ucActive = FF_getChar( pucBuffer, ( uint32_t ) ( uxOffset + FF_FAT_PTBL_ACTIVE ) );
pxParts->ucPartitionID = FF_getChar( pucBuffer, ( uint32_t ) ( uxOffset + FF_FAT_PTBL_ID ) );
pxParts->ulSectorCount = FF_getLong( pucBuffer, ( uint32_t ) ( uxOffset + FF_FAT_PTBL_SECT_COUNT ) );
pxParts->ulStartLBA = FF_getLong( pucBuffer, ( uint32_t ) ( uxOffset + FF_FAT_PTBL_LBA ) );
}
}
/*-----------------------------------------------------------*/
/* This function will traverse through a chain of extended partitions. */
/* It is protected against rubbish data by a counter. */
static FF_Error_t FF_ParseExtended( FF_IOManager_t * pxIOManager,
uint32_t ulFirstSector,
uint32_t ulFirstSize,
FF_SPartFound_t * pPartsFound )
{
uint32_t ulThisSector, ulThisSize;
uint32_t ulSectorSize = pxIOManager->usSectorSize / 512;
uint32_t prevTotalSectors = pxIOManager->xPartition.ulTotalSectors;
FF_Buffer_t * pxBuffer = NULL;
BaseType_t xTryCount = 100;
BaseType_t xPartNr;
BaseType_t xExtendedPartNr;
FF_Error_t xError = FF_ERR_NONE;
FF_Part_t pxPartitions[ 4 ];
ulThisSector = ulFirstSector;
ulThisSize = ulFirstSize;
/* Disable sector checking in FF_BlockRead, because the
* exact disk (partition) parameters are not yet known.
* Let user driver return an error is appropriate. */
pxIOManager->xPartition.ulTotalSectors = 0;
while( xTryCount-- )
{
if( ( pxBuffer == NULL ) || ( pxBuffer->ulSector != ulThisSector ) )
{
/* Moving to a different sector. Release the
* previous one and allocate a new buffer. */
if( pxBuffer != NULL )
{
xError = FF_ReleaseBuffer( pxIOManager, pxBuffer );
pxBuffer = NULL;
if( FF_isERR( xError ) )
{
break;
}
}
FF_PRINTF( "FF_ParseExtended: Read sector %u\n", ( unsigned ) ulThisSector );
pxBuffer = FF_GetBuffer( pxIOManager, ulThisSector, FF_MODE_READ );
if( pxBuffer == NULL )
{
xError = FF_createERR( FF_ERR_DEVICE_DRIVER_FAILED, FF_PARSEEXTENDED );
break;
}
}
{
uint8_t a = FF_getChar( pxBuffer->pucBuffer, FF_FAT_MBR_SIGNATURE + 0 );
uint8_t b = FF_getChar( pxBuffer->pucBuffer, FF_FAT_MBR_SIGNATURE + 1 );
if( ( a != 0x55 ) || ( b != 0xAA ) )
{
FF_PRINTF( "FF_ParseExtended: No signature %02X,%02X\n", a, b );
break;
}
}
/* Check for data partition(s),
* and remember if there is an extended partition */
FF_ReadParts( pxBuffer->pucBuffer, pxPartitions );
/* Assume there is no next ext partition. */
xExtendedPartNr = -1;
for( xPartNr = 0; xPartNr < 4; xPartNr++ )
{
uint32_t ulOffset, ulSize, ulNext;
if( pxPartitions[ xPartNr ].ulSectorCount == 0 )
{
/* Partition is empty */
continue;
}