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-rw-r--r--c/src/lib/libbsp/arm/nds/libfat/source/file_allocation_table.c331
1 files changed, 0 insertions, 331 deletions
diff --git a/c/src/lib/libbsp/arm/nds/libfat/source/file_allocation_table.c b/c/src/lib/libbsp/arm/nds/libfat/source/file_allocation_table.c
deleted file mode 100644
index f85ec3b196..0000000000
--- a/c/src/lib/libbsp/arm/nds/libfat/source/file_allocation_table.c
+++ /dev/null
@@ -1,331 +0,0 @@
-/*
- file_allocation_table.c
- Reading, writing and manipulation of the FAT structure on
- a FAT partition
-
- 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
-
- 2006-07-11 - Chishm
- * Made several fixes related to free clusters, thanks to Loopy
-
- 2006-10-01 - Chishm
- * Added _FAT_fat_linkFreeClusterCleared to clear a cluster when it is allocated
-*/
-
-
-#include "file_allocation_table.h"
-#include "partition.h"
-#include <string.h>
-
-/*
-Gets the cluster linked from input cluster
-*/
-u32 _FAT_fat_nextCluster(PARTITION* partition, u32 cluster)
-{
- u32 nextCluster = CLUSTER_FREE;
- u32 sector;
- int offset;
-
- switch (partition->filesysType)
- {
- case FS_UNKNOWN:
- nextCluster = CLUSTER_FREE;
- break;
-
- case FS_FAT12:
- sector = partition->fat.fatStart + (((cluster * 3) / 2) / BYTES_PER_READ);
- offset = ((cluster * 3) / 2) % BYTES_PER_READ;
-
-
- _FAT_cache_readPartialSector (partition->cache, &nextCluster, sector, offset, sizeof(u8));
-
- offset++;
-
- if (offset >= BYTES_PER_READ) {
- offset = 0;
- sector++;
- }
-
- _FAT_cache_readPartialSector (partition->cache, ((u8*)&nextCluster) + sizeof(u8), sector, offset, sizeof(u8));
-
- if (cluster & 0x01) {
- nextCluster = nextCluster >> 4;
- } else {
- nextCluster &= 0x0FFF;
- }
-
- if (nextCluster >= 0x0FF7)
- {
- nextCluster = CLUSTER_EOF;
- }
-
- break;
-
- case FS_FAT16:
- sector = partition->fat.fatStart + ((cluster << 1) / BYTES_PER_READ);
- offset = (cluster % (BYTES_PER_READ >> 1)) << 1;
-
- _FAT_cache_readPartialSector (partition->cache, &nextCluster, sector, offset, sizeof(u16));
-
- if (nextCluster >= 0xFFF7)
- {
- nextCluster = CLUSTER_EOF;
- }
- break;
-
- case FS_FAT32:
- sector = partition->fat.fatStart + ((cluster << 2) / BYTES_PER_READ);
- offset = (cluster % (BYTES_PER_READ >> 2)) << 2;
-
- _FAT_cache_readPartialSector (partition->cache, &nextCluster, sector, offset, sizeof(u32));
-
- if (nextCluster >= 0x0FFFFFF7)
- {
- nextCluster = CLUSTER_EOF;
- }
- break;
-
- default:
- nextCluster = CLUSTER_FREE;
- break;
- }
-
- return nextCluster;
-}
-
-/*
-writes value into the correct offset within a partition's FAT, based
-on the cluster number.
-*/
-static bool _FAT_fat_writeFatEntry (PARTITION* partition, u32 cluster, u32 value) {
- u32 sector;
- int offset;
- u8 oldValue;
-
- if ((cluster < 0x0002) || (cluster > partition->fat.lastCluster))
- {
- return false;
- }
-
- switch (partition->filesysType)
- {
- case FS_UNKNOWN:
- return false;
- break;
-
- case FS_FAT12:
- sector = partition->fat.fatStart + (((cluster * 3) / 2) / BYTES_PER_READ);
- offset = ((cluster * 3) / 2) % BYTES_PER_READ;
-
- if (cluster & 0x01) {
-
- _FAT_cache_readPartialSector (partition->cache, &oldValue, sector, offset, sizeof(u8));
-
- value = (value << 4) | (oldValue & 0x0F);
-
- _FAT_cache_writePartialSector (partition->cache, &value, sector, offset, sizeof(u8));
-
- offset++;
- if (offset >= BYTES_PER_READ) {
- offset = 0;
- sector++;
- }
-
- _FAT_cache_writePartialSector (partition->cache, ((u8*)&value) + sizeof(u8), sector, offset, sizeof(u8));
-
- } else {
-
- _FAT_cache_writePartialSector (partition->cache, &value, sector, offset, sizeof(u8));
-
- offset++;
- if (offset >= BYTES_PER_READ) {
- offset = 0;
- sector++;
- }
-
- _FAT_cache_readPartialSector (partition->cache, &oldValue, sector, offset, sizeof(u8));
-
- value = ((value >> 8) & 0x0F) | (oldValue & 0xF0);
-
- _FAT_cache_writePartialSector (partition->cache, &value, sector, offset, sizeof(u8));
- }
-
- break;
-
- case FS_FAT16:
- sector = partition->fat.fatStart + ((cluster << 1) / BYTES_PER_READ);
- offset = (cluster % (BYTES_PER_READ >> 1)) << 1;
-
- _FAT_cache_writePartialSector (partition->cache, &value, sector, offset, sizeof(u16));
-
- break;
-
- case FS_FAT32:
- sector = partition->fat.fatStart + ((cluster << 2) / BYTES_PER_READ);
- offset = (cluster % (BYTES_PER_READ >> 2)) << 2;
-
- _FAT_cache_writePartialSector (partition->cache, &value, sector, offset, sizeof(u32));
-
- break;
-
- default:
- return false;
- break;
- }
-
- return true;
-}
-
-/*-----------------------------------------------------------------
-gets the first available free cluster, sets it
-to end of file, links the input cluster to it then returns the
-cluster number
-If an error occurs, return CLUSTER_FREE
------------------------------------------------------------------*/
-u32 _FAT_fat_linkFreeCluster(PARTITION* partition, u32 cluster) {
- u32 firstFree;
- u32 curLink;
- u32 lastCluster;
- bool loopedAroundFAT = false;
-
- lastCluster = partition->fat.lastCluster;
-
- if (cluster > lastCluster) {
- return CLUSTER_FREE;
- }
-
- // Check if the cluster already has a link, and return it if so
- curLink = _FAT_fat_nextCluster(partition, cluster);
- if ((curLink >= CLUSTER_FIRST) && (curLink <= lastCluster)) {
- return curLink; // Return the current link - don't allocate a new one
- }
-
- // Get a free cluster
- firstFree = partition->fat.firstFree;
- // Start at first valid cluster
- if (firstFree < CLUSTER_FIRST) {
- firstFree = CLUSTER_FIRST;
- }
-
- // Search until a free cluster is found
- while (_FAT_fat_nextCluster(partition, firstFree) != CLUSTER_FREE) {
- firstFree++;
- if (firstFree > lastCluster) {
- if (loopedAroundFAT) {
- // If couldn't get a free cluster then return, saying this fact
- partition->fat.firstFree = firstFree;
- return CLUSTER_FREE;
- } else {
- // Try looping back to the beginning of the FAT
- // This was suggested by loopy
- firstFree = CLUSTER_FIRST;
- loopedAroundFAT = true;
- }
- }
- }
- partition->fat.firstFree = firstFree;
-
- if ((cluster >= CLUSTER_FIRST) && (cluster < lastCluster))
- {
- // Update the linked from FAT entry
- _FAT_fat_writeFatEntry (partition, cluster, firstFree);
- }
- // Create the linked to FAT entry
- _FAT_fat_writeFatEntry (partition, firstFree, CLUSTER_EOF);
-
- return firstFree;
-}
-
-/*-----------------------------------------------------------------
-gets the first available free cluster, sets it
-to end of file, links the input cluster to it, clears the new
-cluster to 0 valued bytes, then returns the cluster number
-If an error occurs, return CLUSTER_FREE
------------------------------------------------------------------*/
-u32 _FAT_fat_linkFreeClusterCleared (PARTITION* partition, u32 cluster) {
- u32 newCluster;
- int i;
- u8 emptySector[BYTES_PER_READ];
-
- // Link the cluster
- newCluster = _FAT_fat_linkFreeCluster(partition, cluster);
-
- if (newCluster == CLUSTER_FREE) {
- return CLUSTER_FREE;
- }
-
- // Clear all the sectors within the cluster
- memset (emptySector, 0, BYTES_PER_READ);
- for (i = 0; i < partition->sectorsPerCluster; i++) {
- _FAT_disc_writeSectors (partition->disc,
- _FAT_fat_clusterToSector (partition, newCluster) + i,
- 1, emptySector);
- }
-
- return newCluster;
-}
-
-
-/*-----------------------------------------------------------------
-_FAT_fat_clearLinks
-frees any cluster used by a file
------------------------------------------------------------------*/
-bool _FAT_fat_clearLinks (PARTITION* partition, u32 cluster) {
- u32 nextCluster;
-
- if ((cluster < 0x0002) || (cluster > partition->fat.lastCluster))
- return false;
-
- // If this clears up more space in the FAT before the current free pointer, move it backwards
- if (cluster < partition->fat.firstFree) {
- partition->fat.firstFree = cluster;
- }
-
- while ((cluster != CLUSTER_EOF) && (cluster != CLUSTER_FREE)) {
- // Store next cluster before erasing the link
- nextCluster = _FAT_fat_nextCluster (partition, cluster);
-
- // Erase the link
- _FAT_fat_writeFatEntry (partition, cluster, CLUSTER_FREE);
-
- // Move onto next cluster
- cluster = nextCluster;
- }
-
- return true;
-}
-
-/*-----------------------------------------------------------------
-_FAT_fat_lastCluster
-Trace the cluster links until the last one is found
------------------------------------------------------------------*/
-u32 _FAT_fat_lastCluster (PARTITION* partition, u32 cluster) {
- while ((_FAT_fat_nextCluster(partition, cluster) != CLUSTER_FREE) && (_FAT_fat_nextCluster(partition, cluster) != CLUSTER_EOF)) {
- cluster = _FAT_fat_nextCluster(partition, cluster);
- }
- return cluster;
-}
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