SysCheck-ModMii-Edition/source/fatMounter.c
2013-10-12 18:38:34 +00:00

197 lines
5.2 KiB
C

#include <fat.h>
#include <gccore.h>
#include <string.h>
#include <sdcard/wiisd_io.h>
#include <ogc/usbstorage.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <ogcsys.h>
// These are the only stable and speed is good
#define CACHE 8
#define SECTORS 64
#define BYTES_PER_READ 512
extern DISC_INTERFACE __io_usbstorage;
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
};
static const char FAT_SIG[3] = {'F', 'A', 'T'};
static bool _FAT_partition_isFAT(const DISC_INTERFACE* disc, sec_t startSector)
{
uint8_t sectorBuffer[BYTES_PER_READ] = {0};
if (!disc->readSectors(startSector, 1, sectorBuffer)) return false;
// Make sure it is a valid BPB
if ((sectorBuffer[BPB_bootSig_55] != 0x55) || (sectorBuffer[BPB_bootSig_AA] != 0xAA)) return false;
// Now verify that this is indeed a FAT partition
if (memcmp(sectorBuffer + BPB_FAT16_fileSysType, FAT_SIG, sizeof(FAT_SIG)) && memcmp(sectorBuffer + BPB_FAT32_fileSysType, FAT_SIG, sizeof(FAT_SIG))) return false;
// Check again for the last two cases to make sure that we really have a FAT filesystem here and won't corrupt any data
if(memcmp(sectorBuffer + BPB_FAT16_fileSysType, "FAT", 3) != 0 && memcmp(sectorBuffer + BPB_FAT32_fileSysType, "FAT32", 5) != 0) return false;
return true;
}
static inline uint32_t u8array_to_u32 (const uint8_t* item, int offset)
{
return (item[offset] | (item[offset + 1] << 8) | (item[offset + 2] << 16) | (item[offset + 3] << 24));
}
sec_t GetFATPartition(const DISC_INTERFACE* disc)
{
int i;
uint8_t sectorBuffer[BYTES_PER_READ] = {0};
sec_t startSector = 0;
if (!disc->startup()) return 0;
// Read first sector of disc
if (!disc->readSectors(0, 1, sectorBuffer)) startSector = 0;
// Make sure it is a valid MBR or boot sector
if ((sectorBuffer[BPB_bootSig_55] != 0x55) || (sectorBuffer[BPB_bootSig_AA] != 0xAA)) startSector = 0;
if (!memcmp(sectorBuffer+BPB_FAT16_fileSysType, FAT_SIG, sizeof(FAT_SIG)))
{
// Check if there is a FAT string, which indicates this is a boot sector
startSector = 0;
}
else if (!memcmp(sectorBuffer+BPB_FAT32_fileSysType, FAT_SIG, sizeof(FAT_SIG)))
{
// Check for FAT32
startSector = 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 find an active partition, check for FAT Partition
if (i != 0x1FE && !_FAT_partition_isFAT(disc, u8array_to_u32(sectorBuffer, 0x8+i))) i = 0x1FE;
// If it didn't find an active partition, search for any valid partition
if (i == 0x1FE)
{
for (i = 0x1BE; i < 0x1FE; i+= 0x10)
{
if (sectorBuffer[i+0x04] != 0x00 && _FAT_partition_isFAT(disc, u8array_to_u32(sectorBuffer, 0x8+i))) break;
}
}
if (i != 0x1FE) startSector = u8array_to_u32(sectorBuffer, 0x8+i);
}
disc->shutdown();
return startSector;
}
int MountSD(void)
{
// Close all open files write back the cache and then shutdown them
fatUnmount("SD:/");
// Mount first FAT partition
if (fatMount("SD", &__io_wiisd, GetFATPartition(&__io_wiisd), CACHE, SECTORS)) return 1;
return -1;
}
void UnmountSD(void)
{
// Close all open files write back the cache and then shutdown them
fatUnmount("SD:/");
}
int MountUSB(void)
{
char dirpath[256];
s32 ret;
/* Initialize interface */
ret = __io_usbstorage.startup();
if (!ret)
return -1;
/* Mount device */
ret = fatMountSimple("usb", &__io_usbstorage);
if (!ret)
return -2;
/* Set root directory */
sprintf(dirpath, "usb:/");
chdir(dirpath);
return 0;
}
void UnmountUSB(void)
{
/* Unmount device */
fatUnmount("usb");
/* Shutdown interface */
__io_usbstorage.shutdown();
}