diff options
Diffstat (limited to 'sdk-modifications/libsrc/fs/fatfile.c')
| -rw-r--r-- | sdk-modifications/libsrc/fs/fatfile.c | 889 |
1 files changed, 889 insertions, 0 deletions
diff --git a/sdk-modifications/libsrc/fs/fatfile.c b/sdk-modifications/libsrc/fs/fatfile.c new file mode 100644 index 0000000..304da34 --- /dev/null +++ b/sdk-modifications/libsrc/fs/fatfile.c @@ -0,0 +1,889 @@ +/*
+ fatfile.c
+
+ Functions used by the newlib disc stubs to interface with
+ this library
+
+ Copyright (c) 2006 Michael "Chishm" Chisholm
+
+ Redistribution and use in source and binary forms, with or without modification,
+ are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation and/or
+ other materials provided with the distribution.
+ 3. The name of the author may not be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+ 2006-07-11 - Chishm
+ * Original release
+
+ 2006-07-17 - Chishm
+ * Made all path inputs const char*
+ * Added _FAT_rename_r
+
+ 2006-08-02 - Chishm
+ * Fixed _FAT_seek_r
+
+ 2006-08-13 - Chishm
+ * Moved all externally visible directory related functions to fatdir
+*/
+//version 1.12
+
+#include "fatfile.h"
+
+#include <fcntl.h>
+#include <string.h>
+#include <errno.h>
+#include <ctype.h>
+#include <unistd.h>
+
+#include "fs_cache.h"
+#include "file_allocation_table.h"
+#include "bit_ops.h"
+#include "filetime.h"
+
+
+int _FAT_open_r (struct _reent *r, void *fileStruct, const char *path, int flags) {
+ PARTITION* partition = NULL;
+ bool fileExists;
+ DIR_ENTRY dirEntry;
+ const char* pathEnd;
+ u32 dirCluster;
+ FILE_STRUCT* file = (FILE_STRUCT*) fileStruct;
+
+
+
+ partition = _FAT_partition_getPartitionFromPath (path);
+
+ if (partition == NULL) {
+ r->_errno = ENODEV;
+ return -1;
+ }
+
+
+ // Move the path pointer to the start of the actual path
+ if (strchr (path, ':') != NULL) {
+ path = strchr (path, ':') + 1;
+ }
+ if (strchr (path, ':') != NULL) {
+ r->_errno = EINVAL;
+ return -1;
+ }
+
+ // Determine which mode the file is openned for
+ if ((flags & 0x03) == O_RDONLY) {
+ // Open the file for read-only access
+ file->read = true;
+ file->write = false;
+ file->append = false;
+ } else if ((flags & 0x03) == O_WRONLY) {
+ // Open file for write only access
+ file->read = false;
+ file->write = true;
+ file->append = false;
+ } else if ((flags & 0x03) == O_RDWR) {
+ // Open file for read/write access
+ file->read = true;
+ file->write = true;
+ file->append = false;
+ } else {
+ r->_errno = EACCES;
+ return -1;
+ }
+
+ // Make sure we aren't trying to write to a read-only disc
+ if (file->write && partition->readOnly) {
+ r->_errno = EROFS;
+ return -1;
+ }
+
+ // Search for the file on the disc
+ fileExists = _FAT_directory_entryFromPath (partition, &dirEntry, path, NULL);
+
+ // The file shouldn't exist if we are trying to create it
+ if ((flags & O_CREAT) && (flags & O_EXCL) && fileExists) {
+ r->_errno = EEXIST;
+ return -1;
+ }
+
+ // It should not be a directory if we're openning a file,
+ if (fileExists && _FAT_directory_isDirectory(&dirEntry)) {
+ r->_errno = EISDIR;
+ return -1;
+ }
+ // If the file doesn't exist, create it if we're allowed to
+ if (!fileExists) {
+ if (flags & O_CREAT) {
+ if (partition->readOnly) {
+ // We can't write to a read-only partition
+ r->_errno = EROFS;
+ return -1;
+ }
+ // Create the file
+ // Get the directory it has to go in
+ pathEnd = strrchr (path, DIR_SEPARATOR);
+ if (pathEnd == NULL) {
+ // No path was specified
+ dirCluster = partition->cwdCluster;
+ pathEnd = path;
+ } else {
+ // Path was specified -- get the right dirCluster
+ // Recycling dirEntry, since it needs to be recreated anyway
+ if (!_FAT_directory_entryFromPath (partition, &dirEntry, path, pathEnd) ||
+ !_FAT_directory_isDirectory(&dirEntry)) {
+ r->_errno = ENOTDIR;
+ return -1;
+ }
+ dirCluster = _FAT_directory_entryGetCluster (dirEntry.entryData);
+ // Move the pathEnd past the last DIR_SEPARATOR
+ pathEnd += 1;
+ }
+ // Create the entry data
+ strncpy (dirEntry.d_name, pathEnd, MAX_FILENAME_LENGTH - 1);
+ memset (dirEntry.entryData, 0, DIR_ENTRY_DATA_SIZE);
+
+ // Set the creation time and date
+ dirEntry.entryData[DIR_ENTRY_cTime_ms] = 0;
+ u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cTime, _FAT_filetime_getTimeFromRTC());
+ u16_to_u8array (dirEntry.entryData, DIR_ENTRY_cDate, _FAT_filetime_getDateFromRTC());
+
+ if (!_FAT_directory_addEntry (partition, &dirEntry, dirCluster)) {
+ r->_errno = ENOSPC;
+ return -1;
+ }
+ } else {
+ // file doesn't exist, and we aren't creating it
+ r->_errno = ENOENT;
+ return -1;
+ }
+ }
+
+ file->filesize = u8array_to_u32 (dirEntry.entryData, DIR_ENTRY_fileSize);
+ /* Allow LARGEFILEs with undefined results
+ // Make sure that the file size can fit in the available space
+ if (!(flags & O_LARGEFILE) && (file->filesize >= (1<<31))) {
+ r->_errno = EFBIG;
+ return -1;
+ }
+ */
+
+ // Make sure we aren't trying to write to a read-only file
+ if (file->write && !_FAT_directory_isWritable(&dirEntry)) {
+ r->_errno = EROFS;
+ return -1;
+ }
+
+ // Associate this file with a particular partition
+ file->partition = partition;
+ file->startCluster = _FAT_directory_entryGetCluster (dirEntry.entryData);
+
+ // Truncate the file if requested
+ if ((flags & O_TRUNC) && file->write && (file->startCluster != 0)) {
+ _FAT_fat_clearLinks (partition, file->startCluster);
+ file->startCluster = 0;
+ file->filesize = 0;
+ }
+
+ // Get a new cluster for the file if required
+ if (file->startCluster == 0) {
+ file->startCluster = _FAT_fat_linkFreeCluster (partition, CLUSTER_FREE);
+ }
+
+ // Remember the position of this file's directory entry
+ file->dirEntryStart = dirEntry.dataStart; // Points to the start of the LFN entries of a file, or the alias for no LFN
+ file->dirEntryEnd = dirEntry.dataEnd;
+
+ file->currentPosition = 0;
+
+ file->rwPosition.cluster = file->startCluster;
+ file->rwPosition.sector = 0;
+ file->rwPosition.byte = 0;
+
+
+ if (flags & O_APPEND) {
+ file->append = true;
+ file->appendPosition.cluster = _FAT_fat_lastCluster (partition, file->startCluster);
+ file->appendPosition.sector = (file->filesize % partition->bytesPerCluster) / BYTES_PER_READ;
+ file->appendPosition.byte = file->filesize % BYTES_PER_READ;
+
+ // Check if the end of the file is on the end of a cluster
+ if ( (file->filesize > 0) && ((file->filesize % partition->bytesPerCluster)==0) ){
+ // Set flag to allocate a new cluster
+ file->appendPosition.sector = partition->sectorsPerCluster;
+ file->appendPosition.byte = 0;
+ }
+ } else{
+ file->append = false;
+ file->appendPosition = file->rwPosition;
+ }
+
+ file->inUse = true;
+
+ partition->openFileCount += 1;
+
+ return (int) file;
+}
+
+int _FAT_close_r (struct _reent *r, int fd) {
+ FILE_STRUCT* file = (FILE_STRUCT*) fd;
+ u8 dirEntryData[DIR_ENTRY_DATA_SIZE];
+
+ if (!file->inUse) {
+ r->_errno = EBADF;
+ return -1;
+ }
+ if (file->write) {
+ // Load the old entry
+ _FAT_cache_readPartialSector (file->partition->cache, dirEntryData,
+ _FAT_fat_clusterToSector(file->partition, file->dirEntryEnd.cluster) + file->dirEntryEnd.sector,
+ file->dirEntryEnd.offset * DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE);
+
+ // Write new data to the directory entry
+ // File size
+ u32_to_u8array (dirEntryData, DIR_ENTRY_fileSize, file->filesize);
+
+ // Start cluster
+ u16_to_u8array (dirEntryData, DIR_ENTRY_cluster, file->startCluster);
+ u16_to_u8array (dirEntryData, DIR_ENTRY_clusterHigh, file->startCluster >> 16);
+
+ // Modification time and date
+ u16_to_u8array (dirEntryData, DIR_ENTRY_mTime, _FAT_filetime_getTimeFromRTC());
+ u16_to_u8array (dirEntryData, DIR_ENTRY_mDate, _FAT_filetime_getDateFromRTC());
+
+ // Access date
+ u16_to_u8array (dirEntryData, DIR_ENTRY_aDate, _FAT_filetime_getDateFromRTC());
+
+ // Write the new entry
+ _FAT_cache_writePartialSector (file->partition->cache, dirEntryData,
+ _FAT_fat_clusterToSector(file->partition, file->dirEntryEnd.cluster) + file->dirEntryEnd.sector,
+ file->dirEntryEnd.offset * DIR_ENTRY_DATA_SIZE, DIR_ENTRY_DATA_SIZE);
+
+ // Flush any sectors in the disc cache
+ if (!_FAT_cache_flush(file->partition->cache)) {
+ r->_errno = EIO;
+ return -1;
+ }
+ }
+
+ file->inUse = false;
+ file->partition->openFileCount -= 1;
+
+ return 0;
+}
+
+int _FAT_read_r (struct _reent *r, int fd, char *ptr, int len) {
+ FILE_STRUCT* file = (FILE_STRUCT*) fd;
+ PARTITION* partition;
+ CACHE* cache;
+
+ FILE_POSITION position;
+ u32 tempNextCluster;
+
+ int tempVar;
+
+ u32 remain;
+
+ bool flagNoError = true;
+
+ // Make sure we can actually read from the file
+ if ((file == NULL) || !file->inUse || !file->read) {
+ r->_errno = EBADF;
+ return 0;
+ }
+
+ // Don't try to read if the read pointer is past the end of file
+ if (file->currentPosition >= file->filesize) {
+ return 0;
+ }
+
+ // Don't read past end of file
+ if (len + file->currentPosition > file->filesize) {
+ r->_errno = EOVERFLOW;
+ len = file->filesize - file->currentPosition;
+ }
+
+ remain = len; //Assume len > 0
+
+ position = file->rwPosition;
+
+ partition = file->partition;
+ cache = file->partition->cache;
+
+ // Move onto next cluster if needed
+ if (position.sector >= partition->sectorsPerCluster) {
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if (tempNextCluster == CLUSTER_EOF) {
+ position.sector = partition->sectorsPerCluster;
+ } else if (tempNextCluster == CLUSTER_FREE) {
+ r->_errno = EIO;
+ return 0;
+ } else {
+ position.sector = 0;
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ // Align to sector
+ tempVar = BYTES_PER_READ - position.byte;
+ if (tempVar > remain) {
+ tempVar = remain;
+ }
+
+ if (tempVar < BYTES_PER_READ)
+ {
+ _FAT_cache_readPartialSector ( cache, ptr, _FAT_fat_clusterToSector (partition, position.cluster) + position.sector,
+ position.byte, tempVar);
+
+ remain -= tempVar;
+ ptr += tempVar;
+
+ position.byte += tempVar;
+ if (position.byte >= BYTES_PER_READ) {
+ position.byte = 0;
+ position.sector++;
+ }
+ }
+
+ // Align to cluster
+ //remaining more than 1 sector and read part of cluster
+ if((remain >= BYTES_PER_READ) && (position.sector < partition->sectorsPerCluster))
+ {
+ // tempVar is number of sectors to write
+ tempVar = remain / BYTES_PER_READ;
+ if(tempVar > (partition->sectorsPerCluster - position.sector))
+ tempVar = partition->sectorsPerCluster - position.sector;
+
+ // read several sectors from disk
+ _FAT_disc_readSectors (partition->disc, _FAT_fat_clusterToSector (partition, position.cluster) + position.sector,
+ tempVar, ptr);
+
+ ptr += tempVar * BYTES_PER_READ;
+ remain -= tempVar * BYTES_PER_READ;
+ position.sector += tempVar;
+ }
+
+ // Move onto next cluster
+ // It should get to here without reading anything if a cluster is due to be allocated
+ if ((remain>0) && (position.sector >= partition->sectorsPerCluster)) {
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if (tempNextCluster == CLUSTER_EOF) {
+ position.sector = partition->sectorsPerCluster;
+ } else if (tempNextCluster == CLUSTER_FREE) {
+ r->_errno = EIO;
+ flagNoError = false;
+ } else {
+ position.sector = 0;
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ // Read in whole clusters
+ while ((remain >= partition->bytesPerCluster) && flagNoError) {
+ _FAT_disc_readSectors (partition->disc, _FAT_fat_clusterToSector (partition, position.cluster), partition->sectorsPerCluster, ptr);
+ ptr += partition->bytesPerCluster;
+ remain -= partition->bytesPerCluster;
+
+ // Advance to next cluster
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((remain == 0) && (tempNextCluster == CLUSTER_EOF)) {
+ position.sector = partition->sectorsPerCluster;
+ } else if (tempNextCluster == CLUSTER_FREE) {
+ r->_errno = EIO;
+ flagNoError = false;
+ } else {
+ position.sector = 0;
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ // Read remaining sectors
+ tempVar = remain / BYTES_PER_READ; // Number of sectors left
+ if ((tempVar > 0) && flagNoError) {
+ _FAT_disc_readSectors (partition->disc, _FAT_fat_clusterToSector (partition, position.cluster),
+ tempVar, ptr);
+ ptr += tempVar * BYTES_PER_READ;
+ remain -= tempVar * BYTES_PER_READ;
+ position.sector += tempVar;
+ }
+
+ // Last remaining sector
+ // Check if anything is left
+ if ((remain > 0) && flagNoError) {
+ _FAT_cache_readPartialSector ( cache, ptr,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain);
+ position.byte += remain;
+ remain = 0;
+ }
+
+ // Length read is the wanted length minus the stuff not read
+ len = len - remain;
+
+ // Update file information
+ file->rwPosition = position;
+ file->currentPosition += len;
+
+ return len;
+}
+
+/*
+Extend a file so that the size is the same as the rwPosition
+*/
+static bool file_extend_r (struct _reent *r, FILE_STRUCT* file) {
+ PARTITION* partition = file->partition;
+ CACHE* cache = file->partition->cache;
+
+ FILE_POSITION position;
+
+ u32 remain;
+
+ u8 zeroBuffer [BYTES_PER_READ] = {0};
+
+ u32 tempNextCluster;
+
+ position.byte = file->filesize % BYTES_PER_READ;
+
+ u32 partCluster = file->filesize % partition->bytesPerCluster;
+ if(0 == partCluster && 0 != file->filesize) //integer cluster
+ partCluster = partition->bytesPerCluster;
+ //position.sector = (file->filesize % partition->bytesPerCluster) / BYTES_PER_READ;
+ position.sector = partCluster / BYTES_PER_READ;
+
+ //This function index the last Cluster currently used, when file size equal Cluster size, will cause problem
+ position.cluster = _FAT_fat_lastCluster (partition, file->startCluster);
+
+ remain = file->currentPosition - file->filesize;
+
+ // Move onto next cluster if needed
+ if (position.sector >= partition->sectorsPerCluster) {
+ //Because _FAT_fat_lastCluster point to the last cluster currently used, so
+ //position.sector == partition->sectorsPerCluster means, the last cluster all used
+ //move to next cluster
+ position.sector = 0;
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) {
+ // Ran out of clusters so get a new one
+ tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster);
+ }
+ if (tempNextCluster == CLUSTER_FREE) {
+ // Couldn't get a cluster, so abort
+ r->_errno = ENOSPC;
+ return false;
+ } else {
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ // Only need to clear to the end of the sector
+ if (remain + position.byte < BYTES_PER_READ) {
+ _FAT_cache_writePartialSector (cache, zeroBuffer,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, position.byte, remain);
+ position.byte += remain;
+ } else {
+ if (position.byte > 0) {
+ _FAT_cache_writePartialSector (cache, zeroBuffer,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, position.byte,
+ BYTES_PER_READ - position.byte);
+ remain -= (BYTES_PER_READ - position.byte);
+ position.byte = 0;
+ position.sector ++;
+ }
+
+ while (remain >= BYTES_PER_READ) {
+ if (position.sector >= partition->sectorsPerCluster) {
+ position.sector = 0;
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) {
+ // Ran out of clusters so get a new one
+ tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster);
+ }
+ if (tempNextCluster == CLUSTER_FREE) {
+ // Couldn't get a cluster, so abort
+ r->_errno = ENOSPC;
+ return false;
+ } else {
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ _FAT_disc_writeSectors (partition->disc,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 1, zeroBuffer);
+ //cancel the dirty state of cahced sctor, not necessary here, the sector haven't allocated yet
+ //_FAT_cache_writePartialSector_check(cache,
+ // _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 1, zeroBuffer);
+
+ remain -= BYTES_PER_READ;
+ position.sector ++;
+ }
+
+ if (position.sector >= partition->sectorsPerCluster) {
+ position.sector = 0;
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) {
+ // Ran out of clusters so get a new one
+ tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster);
+ }
+ if (tempNextCluster == CLUSTER_FREE) {
+ // Couldn't get a cluster, so abort
+ r->_errno = ENOSPC;
+ return false;
+ } else {
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ if (remain > 0) {
+ _FAT_cache_writePartialSector (cache, zeroBuffer,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain);
+ position.byte = remain;
+ }
+ }
+
+ file->rwPosition = position;
+ file->filesize = file->currentPosition;
+ return true;
+}
+
+
+int _FAT_write_r (struct _reent *r,int fd, const char *ptr, int len) {
+ FILE_STRUCT* file = (FILE_STRUCT*) fd;
+
+ PARTITION* partition;
+ CACHE* cache;
+
+ FILE_POSITION position;
+ u32 tempNextCluster;
+
+ int tempVar;
+
+ u32 remain;
+
+ bool flagNoError = true;
+ bool flagAppending = false;
+
+ // Make sure we can actually write to the file
+ if ((file == NULL) || !file->inUse || !file->write) {
+ r->_errno = EBADF;
+ return -1;
+ }
+
+ partition = file->partition;
+ cache = file->partition->cache;
+ remain = len;
+
+ if (file->append) {
+ position = file->appendPosition;
+ flagAppending = true;
+ } else {
+ // If the write pointer is past the end of the file, extend the file to that size,
+ // the extended area set to zero
+ if (file->currentPosition > file->filesize) { //This may accure when fseek called before
+ if (!file_extend_r (r, file)) { //the function have done Cluster moving
+ return 0;
+ }
+ }
+
+ // Write at current read pointer
+ position = file->rwPosition;
+
+ // If it is writing past the current end of file, set appending flag
+ if (len + file->currentPosition > file->filesize) {
+ flagAppending = true;
+ }
+ }
+
+ // Move onto next cluster if needed
+ if (position.sector >= partition->sectorsPerCluster) {
+ position.sector = 0;
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) {
+ // Ran out of clusters so get a new one
+ tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster);
+ }
+ if (tempNextCluster == CLUSTER_FREE) {
+ // Couldn't get a cluster, so abort
+ r->_errno = ENOSPC;
+ flagNoError = false;
+ } else {
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ // Align to sector
+ if(flagNoError && (position.byte > 0))
+ {
+ tempVar = BYTES_PER_READ - position.byte;
+ if (tempVar > remain) {
+ tempVar = remain;
+ }
+
+ // Write partial sector to disk
+ _FAT_cache_writePartialSector (cache, ptr,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, position.byte, tempVar);
+
+ remain -= tempVar;
+ ptr += tempVar;
+ position.byte += tempVar;
+
+ // Move onto next sector
+ if (position.byte >= BYTES_PER_READ) {
+ position.byte = 0;
+ position.sector ++; //here may be needed move to next cluster
+ }
+ }
+
+ // Align to cluster
+ //remaining more than 1 sector and used part of cluster
+ if(flagNoError && (remain >= BYTES_PER_READ) && (position.sector < partition->sectorsPerCluster))
+ {
+ // tempVar is number of sectors to write
+ tempVar = remain / BYTES_PER_READ;
+ if(tempVar > (partition->sectorsPerCluster - position.sector))
+ tempVar = partition->sectorsPerCluster - position.sector;
+
+ // write several sectors to disk
+ _FAT_disc_writeSectors (partition->disc,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, tempVar, ptr);
+ //cancel the dirty state of cached sctor
+ _FAT_cache_writePartialSector_check(cache,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, tempVar, ptr);
+
+ ptr += tempVar * BYTES_PER_READ;
+ remain -= tempVar * BYTES_PER_READ;
+ position.sector += tempVar;
+ }
+
+ // Move onto next cluster if needed
+ if (flagNoError && (position.sector >= partition->sectorsPerCluster) && (remain > 0)) {
+ position.sector = 0;
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) {
+ // Ran out of clusters so get a new one
+ tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster);
+ }
+ if (tempNextCluster == CLUSTER_FREE) {
+ // Couldn't get a cluster, so abort
+ r->_errno = ENOSPC;
+ flagNoError = false;
+ } else {
+ position.cluster = tempNextCluster;
+ }
+ }
+
+ // Write whole clusters
+ while ((remain >= partition->bytesPerCluster) && flagNoError) {
+ _FAT_disc_writeSectors (partition->disc, _FAT_fat_clusterToSector(partition, position.cluster),
+ partition->sectorsPerCluster, ptr);
+ //cancel the dirty state of cahced sctor
+ _FAT_cache_writePartialSector_check(cache, _FAT_fat_clusterToSector(partition, position.cluster),
+ partition->sectorsPerCluster, ptr);
+
+ ptr += partition->bytesPerCluster;
+ remain -= partition->bytesPerCluster;
+ if (remain > 0) {
+ tempNextCluster = _FAT_fat_nextCluster(partition, position.cluster);
+ if ((tempNextCluster == CLUSTER_EOF) || (tempNextCluster == CLUSTER_FREE)) {
+ // Ran out of clusters so get a new one
+ tempNextCluster = _FAT_fat_linkFreeCluster(partition, position.cluster);
+ }
+ if (tempNextCluster == CLUSTER_FREE) {
+ // Couldn't get a cluster, so abort
+ r->_errno = ENOSPC;
+ flagNoError = false;
+ } else {
+ position.cluster = tempNextCluster;
+ }
+ } else {
+ // Allocate a new cluster when next writing the file
+ position.sector = partition->sectorsPerCluster;
+ }
+ }
+
+ // Write remaining sectors
+ // Number of sectors left
+ tempVar = remain / BYTES_PER_READ;
+ if ((tempVar > 0) && flagNoError) {
+ _FAT_disc_writeSectors (partition->disc, _FAT_fat_clusterToSector (partition, position.cluster),
+ tempVar, ptr);
+ //cancel the dirty state of cahced sctor
+ _FAT_cache_writePartialSector_check(cache, _FAT_fat_clusterToSector (partition, position.cluster),
+ tempVar, ptr);
+
+ ptr += tempVar * BYTES_PER_READ;
+ remain -= tempVar * BYTES_PER_READ;
+ position.sector += tempVar;
+ }
+
+ // Last remaining partial sector
+ if ((remain > 0) && flagNoError) {
+ if (flagAppending) {
+ //allocated new sector, erasing remaing unused part
+ //Actually, no necessary. when using fwrite to increase the file size, valid data area end at currentPosition
+ //when using fseek to increase file size, valid data area end at rwPosition, the increased zero area will valid
+ //at next fwrite, fread before this can not read out the increased zero area, the file size also not changed
+ //before next fwrite called
+ _FAT_cache_eraseWritePartialSector ( cache, ptr,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain);
+ } else {
+ _FAT_cache_writePartialSector ( cache, ptr,
+ _FAT_fat_clusterToSector (partition, position.cluster) + position.sector, 0, remain);
+ }
+ position.byte += remain;
+ remain = 0;
+ }
+
+ // Amount read is the originally requested amount minus stuff remaining
+ len = len - remain;
+
+ // Update file information
+ if (file->append) {
+ // Appending doesn't affect the read pointer
+ file->appendPosition = position;
+ file->filesize += len;
+ } else {
+ // Writing also shifts the read pointer
+ file->rwPosition = position;
+ file->currentPosition += len;
+ if (file->filesize < file->currentPosition) {
+ file->filesize = file->currentPosition;
+ }
+ }
+
+ return len;
+}
+
+#include "ds2io.h"
+int _FAT_seek_r (struct _reent *r, int fd, int pos, int dir) {
+ FILE_STRUCT* file = (FILE_STRUCT*) fd;
+
+ PARTITION* partition;
+
+ u32 cluster, nextCluster;
+ int clusCount;
+ int position;
+
+ if ((file == NULL) || (file->inUse == false)) {
+ // invalid file
+ r->_errno = EBADF;
+ return -1;
+ }
+
+ partition = file->partition;
+
+ switch (dir) {
+ case SEEK_SET:
+ position = pos;
+ break;
+ case SEEK_CUR:
+ position = file->currentPosition + pos;
+ break;
+ case SEEK_END:
+ position = file->filesize + pos;
+ break;
+ default:
+ r->_errno = EINVAL;
+ return -1;
+ }
+
+ if ((pos > 0) && (position < 0)) {
+ r->_errno = EOVERFLOW;
+ return -1;
+ }
+
+ if (position < 0) {
+ r->_errno = EINVAL;
+ return -1;
+ }
+
+ // Only change the read/write position if it is within or at the bounds of the current filesize
+ if (file->filesize >= position) {
+
+ // Calculate where the correct cluster is
+ if (position >= file->currentPosition) {
+ clusCount = (position / partition->bytesPerCluster) - (file->currentPosition / partition->bytesPerCluster);
+ cluster = file->rwPosition.cluster;
+ //When last reading, it stop at the cluster boundary,
+ //file->rwPosition.sector == partition->bytesPerCluster, but
+ //file->rwPosition.cluster did not move to next cluster
+ if(file->rwPosition.sector >= partition->sectorsPerCluster)
+ clusCount += 1;
+ } else {
+ clusCount = position / partition->bytesPerCluster;
+ cluster = file->startCluster;
+ }
+
+ // Calculate the sector and byte of the current position, and store them
+ file->rwPosition.sector = (position % partition->bytesPerCluster) / BYTES_PER_READ;
+ file->rwPosition.byte = position % BYTES_PER_READ;
+
+ nextCluster = _FAT_fat_nextCluster (partition, cluster);
+ while ((clusCount > 0) && (nextCluster != CLUSTER_FREE) && (nextCluster != CLUSTER_EOF)) {
+ clusCount--;
+ cluster = nextCluster;
+ nextCluster = _FAT_fat_nextCluster (partition, cluster);
+ }
+
+ // Check if ran out of clusters, and the file is being written to
+ if ((clusCount > 0) && (file->write || file->append)) {
+ // Set flag to allocate a new cluster
+ file->rwPosition.sector = partition->sectorsPerCluster;
+ file->rwPosition.byte = 0;
+ }
+
+ file->rwPosition.cluster = cluster;
+ }
+
+ // Save position
+ file->currentPosition = position;
+
+ return position;
+}
+
+
+
+int _FAT_fstat_r (struct _reent *r, int fd, struct stat *st) {
+ FILE_STRUCT* file = (FILE_STRUCT*) fd;
+
+ PARTITION* partition;
+
+ DIR_ENTRY fileEntry;
+
+ if ((file == NULL) || (file->inUse == false)) {
+ // invalid file
+ r->_errno = EBADF;
+ return -1;
+ }
+
+ partition = file->partition;
+
+ // Get the file's entry data
+ fileEntry.dataStart = file->dirEntryStart;
+ fileEntry.dataEnd = file->dirEntryEnd;
+
+ if (!_FAT_directory_entryFromPosition (partition, &fileEntry)) {
+ r->_errno = EIO;
+ return -1;
+ }
+
+ // Fill in the stat struct
+ _FAT_directory_entryStat (partition, &fileEntry, st);
+
+ // Fix stats that have changed since the file was openned
+ st->st_ino = (ino_t)(file->startCluster); // The file serial number is the start cluster
+ st->st_size = file->filesize; // File size
+
+ return 0;
+}
+
|