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author | aliaspider | 2014-10-28 06:47:04 +0100 |
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committer | aliaspider | 2014-10-28 06:47:04 +0100 |
commit | ad4866e0cb1f7ddefbe1e31a890741e4cbc50181 (patch) | |
tree | 86b8351ca560156abbeaed5e2c1964de38a49544 /sdk-modifications/libsrc/fs/file_allocation_table.c | |
parent | 2b75359c7ea0485b509460ea81606ac8052a6333 (diff) | |
download | snes9x2005-ad4866e0cb1f7ddefbe1e31a890741e4cbc50181.tar.gz snes9x2005-ad4866e0cb1f7ddefbe1e31a890741e4cbc50181.tar.bz2 snes9x2005-ad4866e0cb1f7ddefbe1e31a890741e4cbc50181.zip |
remove unused files
Diffstat (limited to 'sdk-modifications/libsrc/fs/file_allocation_table.c')
-rw-r--r-- | sdk-modifications/libsrc/fs/file_allocation_table.c | 330 |
1 files changed, 0 insertions, 330 deletions
diff --git a/sdk-modifications/libsrc/fs/file_allocation_table.c b/sdk-modifications/libsrc/fs/file_allocation_table.c deleted file mode 100644 index f382b52..0000000 --- a/sdk-modifications/libsrc/fs/file_allocation_table.c +++ /dev/null @@ -1,330 +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; -} |