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+/*
+ partition.c
+ Functions for mounting and dismounting partitions
+ on various block devices.
+
+ 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
+
+ 2006-08-10 - Chishm
+ * Fixed problem when openning files starting with "fat"
+
+ 2006-10-28 - Chishm
+ * _partitions changed to _FAT_partitions to maintain the same style of naming as the functions
+*/
+//version 1.1
+//Note: fix bug in _FAT_partition_setDefaultPartition() function
+
+#include "partition.h"
+#include "bit_ops.h"
+#include "file_allocation_table.h"
+#include "directory.h"
+
+#include <string.h>
+#include <ctype.h>
+
+#include "mem_allocate.h"
+
+/*
+This device name, as known by DevKitPro
+*/
+const char* DEVICE_NAME = "fat";
+
+/*
+Data offsets
+*/
+
+// BIOS Parameter Block offsets
+enum BPB {
+ BPB_jmpBoot = 0x00,
+ BPB_OEMName = 0x03,
+ // BIOS Parameter Block
+ BPB_bytesPerSector = 0x0B,
+ BPB_sectorsPerCluster = 0x0D,
+ BPB_reservedSectors = 0x0E,
+ BPB_numFATs = 0x10,
+ BPB_rootEntries = 0x11,
+ BPB_numSectorsSmall = 0x13,
+ BPB_mediaDesc = 0x15,
+ BPB_sectorsPerFAT = 0x16,
+ BPB_sectorsPerTrk = 0x18,
+ BPB_numHeads = 0x1A,
+ BPB_numHiddenSectors = 0x1C,
+ BPB_numSectors = 0x20,
+ // Ext BIOS Parameter Block for FAT16
+ BPB_FAT16_driveNumber = 0x24,
+ BPB_FAT16_reserved1 = 0x25,
+ BPB_FAT16_extBootSig = 0x26,
+ BPB_FAT16_volumeID = 0x27,
+ BPB_FAT16_volumeLabel = 0x2B,
+ BPB_FAT16_fileSysType = 0x36,
+ // Bootcode
+ BPB_FAT16_bootCode = 0x3E,
+ // FAT32 extended block
+ BPB_FAT32_sectorsPerFAT32 = 0x24,
+ BPB_FAT32_extFlags = 0x28,
+ BPB_FAT32_fsVer = 0x2A,
+ BPB_FAT32_rootClus = 0x2C,
+ BPB_FAT32_fsInfo = 0x30,
+ BPB_FAT32_bkBootSec = 0x32,
+ // Ext BIOS Parameter Block for FAT32
+ BPB_FAT32_driveNumber = 0x40,
+ BPB_FAT32_reserved1 = 0x41,
+ BPB_FAT32_extBootSig = 0x42,
+ BPB_FAT32_volumeID = 0x43,
+ BPB_FAT32_volumeLabel = 0x47,
+ BPB_FAT32_fileSysType = 0x52,
+ // Bootcode
+ BPB_FAT32_bootCode = 0x5A,
+ BPB_bootSig_55 = 0x1FE,
+ BPB_bootSig_AA = 0x1FF
+};
+
+
+#ifdef NDS
+#define MAXIMUM_PARTITIONS 4
+PARTITION* _FAT_partitions[MAXIMUM_PARTITIONS] = {NULL};
+#else // not defined NDS
+#define MAXIMUM_PARTITIONS 1
+PARTITION* _FAT_partitions[MAXIMUM_PARTITIONS] = {NULL};
+#endif // defined NDS
+
+// Use a single static buffer for the partitions
+
+
+static PARTITION* _FAT_partition_constructor ( const IO_INTERFACE* disc, u32 cacheSize) {
+ PARTITION* partition;
+ int i;
+ u32 bootSector;
+ u8 sectorBuffer[BYTES_PER_READ] = {0};
+
+ // Read first sector of disc
+ if ( !_FAT_disc_readSectors (disc, 0, 1, sectorBuffer)) {
+ return NULL;
+ }
+
+ // Make sure it is a valid MBR or boot sector
+ if ( (sectorBuffer[BPB_bootSig_55] != 0x55) || (sectorBuffer[BPB_bootSig_AA] != 0xAA)) {
+ return NULL;
+ }
+
+ // Check if there is a FAT string, which indicates this is a boot sector
+ if ((sectorBuffer[0x36] == 'F') && (sectorBuffer[0x37] == 'A') && (sectorBuffer[0x38] == 'T')) {
+ bootSector = 0;
+ } else if ((sectorBuffer[0x52] == 'F') && (sectorBuffer[0x53] == 'A') && (sectorBuffer[0x54] == 'T')) {
+ // Check for FAT32
+ bootSector = 0;
+ } else {
+ // This is an MBR
+ // Find first valid partition from MBR
+ // First check for an active partition
+ for (i=0x1BE; (i < 0x1FE) && (sectorBuffer[i] != 0x80); i+= 0x10);
+ // If it didn't find an active partition, search for any valid partition
+ if (i == 0x1FE) {
+ for (i=0x1BE; (i < 0x1FE) && (sectorBuffer[i+0x04] == 0x00); i+= 0x10);
+ }
+
+ // Go to first valid partition
+ if ( i != 0x1FE) {
+ // Make sure it found a partition
+ bootSector = u8array_to_u32(sectorBuffer, 0x8 + i);
+ } else {
+ bootSector = 0; // No partition found, assume this is a MBR free disk
+ }
+ }
+
+ // Read in boot sector
+ if ( !_FAT_disc_readSectors (disc, bootSector, 1, sectorBuffer)) {
+ return NULL;
+ }
+
+ partition = (PARTITION*) _FAT_mem_allocate (sizeof(PARTITION));
+ if (partition == NULL) {
+ return NULL;
+ }
+
+ // Set partition's disc interface
+ partition->disc = disc;
+
+ // Store required information about the file system
+ partition->fat.sectorsPerFat = u8array_to_u16(sectorBuffer, BPB_sectorsPerFAT);
+ if (partition->fat.sectorsPerFat == 0) {
+ partition->fat.sectorsPerFat = u8array_to_u32( sectorBuffer, BPB_FAT32_sectorsPerFAT32);
+ }
+
+ partition->numberOfSectors = u8array_to_u16( sectorBuffer, BPB_numSectorsSmall);
+ if (partition->numberOfSectors == 0) {
+ partition->numberOfSectors = u8array_to_u32( sectorBuffer, BPB_numSectors);
+ }
+
+ partition->bytesPerSector = BYTES_PER_READ; // Sector size is redefined to be 512 bytes
+ partition->sectorsPerCluster = sectorBuffer[BPB_sectorsPerCluster] * u8array_to_u16(sectorBuffer, BPB_bytesPerSector) / BYTES_PER_READ;
+ partition->bytesPerCluster = partition->bytesPerSector * partition->sectorsPerCluster;
+ partition->fat.fatStart = bootSector + u8array_to_u16(sectorBuffer, BPB_reservedSectors);
+
+ partition->rootDirStart = partition->fat.fatStart + (sectorBuffer[BPB_numFATs] * partition->fat.sectorsPerFat);
+ partition->dataStart = partition->rootDirStart + (( u8array_to_u16(sectorBuffer, BPB_rootEntries) * DIR_ENTRY_DATA_SIZE) / partition->bytesPerSector);
+
+ partition->totalSize = (partition->numberOfSectors - partition->dataStart) * partition->bytesPerSector;
+
+ // Store info about FAT
+ partition->fat.lastCluster = (partition->numberOfSectors - partition->dataStart) / partition->sectorsPerCluster;
+ partition->fat.firstFree = CLUSTER_FIRST;
+
+ if (partition->fat.lastCluster < CLUSTERS_PER_FAT12) {
+ partition->filesysType = FS_FAT12; // FAT12 volume
+ } else if (partition->fat.lastCluster < CLUSTERS_PER_FAT16) {
+ partition->filesysType = FS_FAT16; // FAT16 volume
+ } else {
+ partition->filesysType = FS_FAT32; // FAT32 volume
+ }
+
+ if (partition->filesysType != FS_FAT32) {
+ partition->rootDirCluster = FAT16_ROOT_DIR_CLUSTER;
+ } else {
+ // Set up for the FAT32 way
+ partition->rootDirCluster = u8array_to_u32(sectorBuffer, BPB_FAT32_rootClus);
+ // Check if FAT mirroring is enabled
+ if (!(sectorBuffer[BPB_FAT32_extFlags] & 0x80)) {
+ // Use the active FAT
+ partition->fat.fatStart = partition->fat.fatStart + ( partition->fat.sectorsPerFat * (sectorBuffer[BPB_FAT32_extFlags] & 0x0F));
+ }
+ }
+
+ // Create a cache to use
+ partition->cache = _FAT_cache_constructor (cacheSize, partition->disc);
+
+ // Set current directory to the root
+ partition->cwdCluster = partition->rootDirCluster;
+
+ // Check if this disc is writable, and set the readOnly property appropriately
+ partition->readOnly = !(_FAT_disc_features(disc) & FEATURE_MEDIUM_CANWRITE);
+
+ // There are currently no open files on this partition
+ partition->openFileCount = 0;
+
+ return partition;
+}
+
+static void _FAT_partition_destructor (PARTITION* partition) {
+ _FAT_cache_destructor (partition->cache);
+ _FAT_disc_shutdown (partition->disc);
+ _FAT_mem_free (partition);
+}
+
+bool _FAT_partition_mount (PARTITION_INTERFACE partitionNumber, u32 cacheSize)
+{
+#ifdef NDS
+ int i;
+ const IO_INTERFACE* disc = NULL;
+
+ if (_FAT_partitions[partitionNumber] != NULL) {
+ return false;
+ }
+
+ switch (partitionNumber) {
+ case PI_SLOT_1:
+ // Mount the disc in slot 1
+ disc = _FAT_disc_dsSlotFindInterface ();
+ break;
+ case PI_SLOT_2:
+ // Mount the disc in slot 2
+ disc = _FAT_disc_gbaSlotFindInterface ();
+ break;
+ case PI_DEFAULT:
+ case PI_CUSTOM:
+ default:
+ // Anything else has to be handled specially
+ return false;
+ break;
+ }
+
+ if (disc == NULL) {
+ return false;
+ }
+
+ // See if that disc is already in use, if so, then just copy the partition pointer
+ for (i = 0; i < MAXIMUM_PARTITIONS; i++) {
+ if ((_FAT_partitions[i] != NULL) && (_FAT_partitions[i]->disc == disc)) {
+ _FAT_partitions[partitionNumber] = _FAT_partitions[i];
+ return true;
+ }
+ }
+
+ _FAT_partitions[partitionNumber] = _FAT_partition_constructor (disc, cacheSize);
+
+ if (_FAT_partitions[partitionNumber] == NULL) {
+ return false;
+ }
+
+#else // not defined NDS
+ const IO_INTERFACE* disc = NULL;
+
+ if (_FAT_partitions[partitionNumber] != NULL) {
+ return false;
+ }
+
+ // Only ever one partition on GBA
+ disc = _FAT_disc_gbaSlotFindInterface ();
+ _FAT_partitions[partitionNumber] = _FAT_partition_constructor (disc, cacheSize);
+
+#endif // defined NDS
+
+ return true;
+}
+
+bool _FAT_partition_mountCustomInterface (const IO_INTERFACE* device, u32 cacheSize) {
+#ifdef NDS
+ int i;
+
+ if (_FAT_partitions[PI_CUSTOM] != NULL) {
+ return false;
+ }
+
+ if (device == NULL) {
+ return false;
+ }
+
+ // See if that disc is already in use, if so, then just copy the partition pointer
+ for (i = 0; i < MAXIMUM_PARTITIONS; i++) {
+ if ((_FAT_partitions[i] != NULL) && (_FAT_partitions[i]->disc == device)) {
+ _FAT_partitions[PI_CUSTOM] = _FAT_partitions[i];
+ return true;
+ }
+ }
+
+ _FAT_partitions[PI_CUSTOM] = _FAT_partition_constructor (device, cacheSize);
+
+ if (_FAT_partitions[PI_CUSTOM] == NULL) {
+ return false;
+ }
+
+#else // not defined NDS
+ if (_FAT_partitions[PI_CART_SLOT] != NULL) {
+ return false;
+ }
+
+ if (device == NULL) {
+ return false;
+ }
+
+ // Only ever one partition on GBA
+ _FAT_partitions[PI_CART_SLOT] = _FAT_partition_constructor (device, cacheSize);
+
+#endif // defined NDS
+
+ return true;
+}
+
+bool _FAT_partition_setDefaultInterface (PARTITION_INTERFACE partitionNumber)
+{
+#ifdef NDS // Can only set the default partition when there is more than 1, so doesn't apply to GBA
+ if ((partitionNumber < 1) || (partitionNumber >= MAXIMUM_PARTITIONS)) {
+ return false;
+ }
+
+ if (_FAT_partitions[partitionNumber] == NULL) {
+ return false;
+ }
+
+ _FAT_partitions[PI_DEFAULT] = _FAT_partitions[partitionNumber];
+#endif
+ return true;
+}
+
+bool _FAT_partition_setDefaultPartition (PARTITION* partition) {
+#ifdef NDS // Can only set the default partition when there is more than 1, so doesn't apply to GBA
+ int i;
+
+ if (partition == NULL) {
+ return false;
+ }
+
+ if(_FAT_partitions[PI_DEFAULT] == partition) //Already is the default partition
+ return true;
+
+ // Ensure that this device is already in the list
+ for (i = 1; i < MAXIMUM_PARTITIONS; i++) {
+ if (_FAT_partitions[i] == partition) {
+ break;
+ }
+ }
+
+ // It wasn't in the list, so fail
+ if (i == MAXIMUM_PARTITIONS) {
+ return false;
+ }
+
+ // Change the default partition / device to this one
+ _FAT_partitions[PI_DEFAULT] = partition;
+
+#endif
+ return true;
+}
+
+bool _FAT_partition_unmount (PARTITION_INTERFACE partitionNumber) {
+ int i;
+ PARTITION* partition = _FAT_partitions[partitionNumber];
+
+ if (partition == NULL) {
+ return false;
+ }
+
+ if (partition->openFileCount > 0) {
+ // There are still open files that need closing
+ return false;
+ }
+
+ // Remove all references to this partition
+ for (i = 0; i < MAXIMUM_PARTITIONS; i++) {
+ if (_FAT_partitions[i] == partition) {
+ _FAT_partitions[i] = NULL;
+ }
+ }
+
+ _FAT_partition_destructor (partition);
+ return true;
+}
+
+bool _FAT_partition_unsafeUnmount (PARTITION_INTERFACE partitionNumber) {
+ int i;
+ PARTITION* partition = _FAT_partitions[partitionNumber];
+
+ if (partition == NULL) {
+ return false;
+ }
+
+ // Remove all references to this partition
+ for (i = 0; i < MAXIMUM_PARTITIONS; i++) {
+ if (_FAT_partitions[i] == partition) {
+ _FAT_partitions[i] = NULL;
+ }
+ }
+
+ _FAT_cache_invalidate (partition->cache);
+ _FAT_partition_destructor (partition);
+ return true;
+}
+
+PARTITION* _FAT_partition_getPartitionFromPath (const char* path) {
+#ifdef NDS
+ int namelen;
+ int partitionNumber;
+
+ // Device name extraction code taken from DevKitPro
+ namelen = strlen(DEVICE_NAME);
+ if (strchr (path, ':') == NULL) {
+ // No device specified
+ partitionNumber = PI_DEFAULT;
+ } else if( strncmp(DEVICE_NAME, path, namelen) == 0 ) {
+ if ( path[namelen] == ':' ) {
+ // Only the device name is specified
+ partitionNumber = PI_DEFAULT;
+ } else if (isdigit(path[namelen]) && path[namelen+1] ==':' ) {
+ // Device name and number specified
+ partitionNumber = path[namelen] - '0';
+ } else {
+ // Incorrect device name
+ return NULL;
+ }
+ } else {
+ // Incorrect device name
+ return NULL;
+ }
+
+ if ((partitionNumber < 0) || (partitionNumber >= MAXIMUM_PARTITIONS)) {
+ return NULL;
+ }
+
+ return _FAT_partitions[partitionNumber];
+#else // not defined NDS
+ // Only one possible partition on GBA
+ return _FAT_partitions[PI_CART_SLOT];
+#endif // defined NDS
+}
+
+bool _FAT_partition_freeMount( int partitionNumber, const IO_INTERFACE* device, u32 cacheSize) {
+
+ if( partitionNumber < 0 || partitionNumber > 3 )
+ return false;
+ int i;
+
+ if (device == NULL) {
+ return false;
+ }
+
+ if (_FAT_partitions[partitionNumber] != NULL) {
+ if(_FAT_partitions[partitionNumber] -> disc == device)
+ return true;
+
+ return false;
+ }
+
+ // See if that disc is already in use, if so, then just copy the partition pointer
+ for (i = 0; i < MAXIMUM_PARTITIONS; i++) {
+ if ((_FAT_partitions[i] != NULL) && (_FAT_partitions[i]->disc == device)) {
+ _FAT_partitions[partitionNumber] = _FAT_partitions[i];
+ return true;
+ }
+ }
+
+ _FAT_partitions[partitionNumber] = _FAT_partition_constructor (device, cacheSize);
+
+ if (_FAT_partitions[partitionNumber] == NULL) {
+ return false;
+ }
+
+ return true;
+}