EFI_STATUS
FatAccessVolumeDirty (
IN FAT_VOLUME *Volume,
IN IO_MODE IoMode,
IN VOID *DirtyValue
)
/*++
Routine Description:
Set the volume as dirty or not
Arguments:
Volume - FAT file system volume.
IoMode - The access mode.
DirtyValue - Set the volume as dirty or not.
Returns:
EFI_SUCCESS - Set the new FAT entry value sucessfully.
other - An error occurred when operation the FAT entries.
--*/
{
UINTN WriteCount;
WriteCount = Volume->FatEntrySize;
return FatDiskIo (Volume, IoMode, Volume->FatPos + WriteCount, WriteCount, DirtyValue);
}
/**
Detects FAT file system on Disk and set relevant fields of Volume.
@param Volume - The volume structure.
@retval EFI_SUCCESS - The Fat File System is detected successfully
@retval EFI_UNSUPPORTED - The volume is not FAT file system.
@retval EFI_VOLUME_CORRUPTED - The volume is corrupted.
**/
EFI_STATUS
FatOpenDevice (
IN OUT FAT_VOLUME *Volume
)
{
EFI_STATUS Status;
UINT32 BlockSize;
UINT32 DirtyMask;
EFI_DISK_IO_PROTOCOL *DiskIo;
FAT_BOOT_SECTOR FatBs;
FAT_VOLUME_TYPE FatType;
UINTN RootDirSectors;
UINTN FatLba;
UINTN RootLba;
UINTN FirstClusterLba;
UINTN Sectors;
UINTN SectorsPerFat;
UINT8 SectorsPerClusterAlignment;
UINT8 BlockAlignment;
//
// Read the FAT_BOOT_SECTOR BPB info
// This is the only part of FAT code that uses parent DiskIo,
// Others use FatDiskIo which utilizes a Cache.
//
DiskIo = Volume->DiskIo;
Status = DiskIo->ReadDisk (DiskIo, Volume->MediaId, 0, sizeof (FatBs), &FatBs);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_INIT, "FatOpenDevice: read of part_lba failed %r\n", Status));
return Status;
}
FatType = FatUndefined;
//
// Use LargeSectors if Sectors is 0
//
Sectors = FatBs.FatBsb.Sectors;
if (Sectors == 0) {
Sectors = FatBs.FatBsb.LargeSectors;
}
SectorsPerFat = FatBs.FatBsb.SectorsPerFat;
if (SectorsPerFat == 0) {
SectorsPerFat = FatBs.FatBse.Fat32Bse.LargeSectorsPerFat;
FatType = Fat32;
}
//
// Is boot sector a fat sector?
// (Note that so far we only know if the sector is FAT32 or not, we don't
// know if the sector is Fat16 or Fat12 until later when we can compute
// the volume size)
//
if (FatBs.FatBsb.ReservedSectors == 0 || FatBs.FatBsb.NumFats == 0 || Sectors == 0) {
return EFI_UNSUPPORTED;
}
if ((FatBs.FatBsb.SectorSize & (FatBs.FatBsb.SectorSize - 1)) != 0) {
return EFI_UNSUPPORTED;
}
BlockAlignment = (UINT8) HighBitSet32 (FatBs.FatBsb.SectorSize);
if (BlockAlignment > MAX_BLOCK_ALIGNMENT || BlockAlignment < MIN_BLOCK_ALIGNMENT) {
return EFI_UNSUPPORTED;
}
if ((FatBs.FatBsb.SectorsPerCluster & (FatBs.FatBsb.SectorsPerCluster - 1)) != 0) {
return EFI_UNSUPPORTED;
}
SectorsPerClusterAlignment = (UINT8) HighBitSet32 (FatBs.FatBsb.SectorsPerCluster);
if (SectorsPerClusterAlignment > MAX_SECTORS_PER_CLUSTER_ALIGNMENT) {
return EFI_UNSUPPORTED;
}
if (FatBs.FatBsb.Media <= 0xf7 &&
FatBs.FatBsb.Media != 0xf0 &&
FatBs.FatBsb.Media != 0x00 &&
FatBs.FatBsb.Media != 0x01
) {
return EFI_UNSUPPORTED;
}
//
// Initialize fields the volume information for this FatType
//
if (FatType != Fat32) {
if (FatBs.FatBsb.RootEntries == 0) {
return EFI_UNSUPPORTED;
}
//
// Unpack fat12, fat16 info
//
Volume->RootEntries = FatBs.FatBsb.RootEntries;
} else {
//
// If this is fat32, refuse to mount mirror-disabled volumes
//
if ((SectorsPerFat == 0 || FatBs.FatBse.Fat32Bse.FsVersion != 0) || (FatBs.FatBse.Fat32Bse.ExtendedFlags & 0x80)) {
return EFI_UNSUPPORTED;
}
//
// Unpack fat32 info
//
Volume->RootCluster = FatBs.FatBse.Fat32Bse.RootDirFirstCluster;
}
Volume->NumFats = FatBs.FatBsb.NumFats;
//
// Compute some fat locations
//
BlockSize = FatBs.FatBsb.SectorSize;
RootDirSectors = ((Volume->RootEntries * sizeof (FAT_DIRECTORY_ENTRY)) + (BlockSize - 1)) / BlockSize;
FatLba = FatBs.FatBsb.ReservedSectors;
RootLba = FatBs.FatBsb.NumFats * SectorsPerFat + FatLba;
FirstClusterLba = RootLba + RootDirSectors;
Volume->FatPos = FatLba * BlockSize;
Volume->FatSize = SectorsPerFat * BlockSize;
Volume->VolumeSize = LShiftU64 (Sectors, BlockAlignment);
Volume->RootPos = LShiftU64 (RootLba, BlockAlignment);
Volume->FirstClusterPos = LShiftU64 (FirstClusterLba, BlockAlignment);
Volume->MaxCluster = (Sectors - FirstClusterLba) >> SectorsPerClusterAlignment;
Volume->ClusterAlignment = (UINT8)(BlockAlignment + SectorsPerClusterAlignment);
Volume->ClusterSize = (UINTN)1 << (Volume->ClusterAlignment);
//
// If this is not a fat32, determine if it's a fat16 or fat12
//
if (FatType != Fat32) {
if (Volume->MaxCluster >= FAT_MAX_FAT16_CLUSTER) {
return EFI_VOLUME_CORRUPTED;
}
FatType = Volume->MaxCluster < FAT_MAX_FAT12_CLUSTER ? Fat12 : Fat16;
//
// fat12 & fat16 fat-entries are 2 bytes
//
Volume->FatEntrySize = sizeof (UINT16);
DirtyMask = FAT16_DIRTY_MASK;
} else {
if (Volume->MaxCluster < FAT_MAX_FAT16_CLUSTER) {
return EFI_VOLUME_CORRUPTED;
}
//
// fat32 fat-entries are 4 bytes
//
Volume->FatEntrySize = sizeof (UINT32);
DirtyMask = FAT32_DIRTY_MASK;
}
//
// Get the DirtyValue and NotDirtyValue
// We should keep the initial value as the NotDirtyValue
// in case the volume is dirty already
//
if (FatType != Fat12) {
Status = FatAccessVolumeDirty (Volume, ReadDisk, &Volume->NotDirtyValue);
if (EFI_ERROR (Status)) {
return Status;
}
Volume->DirtyValue = Volume->NotDirtyValue & DirtyMask;
}
//
// If present, read the fat hint info
//
if (FatType == Fat32) {
Volume->FreeInfoPos = FatBs.FatBse.Fat32Bse.FsInfoSector * BlockSize;
if (FatBs.FatBse.Fat32Bse.FsInfoSector != 0) {
FatDiskIo (Volume, ReadDisk, Volume->FreeInfoPos, sizeof (FAT_INFO_SECTOR), &Volume->FatInfoSector, NULL);
if (Volume->FatInfoSector.Signature == FAT_INFO_SIGNATURE &&
Volume->FatInfoSector.InfoBeginSignature == FAT_INFO_BEGIN_SIGNATURE &&
Volume->FatInfoSector.InfoEndSignature == FAT_INFO_END_SIGNATURE &&
Volume->FatInfoSector.FreeInfo.ClusterCount <= Volume->MaxCluster
) {
Volume->FreeInfoValid = TRUE;
}
}
}
//
// Just make up a FreeInfo.NextCluster for use by allocate cluster
//
if (FAT_MIN_CLUSTER > Volume->FatInfoSector.FreeInfo.NextCluster ||
Volume->FatInfoSector.FreeInfo.NextCluster > Volume->MaxCluster + 1
) {
Volume->FatInfoSector.FreeInfo.NextCluster = FAT_MIN_CLUSTER;
}
//
// We are now defining FAT Type
//
Volume->FatType = FatType;
ASSERT (FatType != FatUndefined);
return EFI_SUCCESS;
}
EFI_STATUS
FatAccessOFile (
IN FAT_OFILE *OFile,
IN IO_MODE IoMode,
IN UINTN Position,
IN OUT UINTN *DataBufferSize,
IN OUT UINT8 *UserBuffer,
IN FAT_TASK *Task
)
/*++
Routine Description:
This function reads data from a file or writes data to a file.
It uses OFile->PosRem to determine how much data can be accessed in one time.
Arguments:
OFile - The open file.
IoMode - Indicate whether the access mode is reading or writing.
Position - The position where data will be accessed.
DataBufferSize - Size of Buffer.
UserBuffer - Buffer containing data.
Returns:
EFI_SUCCESS - Access the data successfully.
other - An error occurred when operating on the disk.
--*/
{
FAT_VOLUME *Volume;
UINTN Len;
EFI_STATUS Status;
UINTN BufferSize;
BufferSize = *DataBufferSize;
Volume = OFile->Volume;
ASSERT_VOLUME_LOCKED (Volume);
Status = EFI_SUCCESS;
while (BufferSize > 0) {
//
// Seek the OFile to the file position
//
Status = FatOFilePosition (OFile, Position, BufferSize);
if (EFI_ERROR (Status)) {
break;
}
//
// Clip length to block run
//
Len = BufferSize > OFile->PosRem ? OFile->PosRem : BufferSize;
//
// Write the data
//
Status = FatDiskIo (Volume, IoMode, OFile->PosDisk, Len, UserBuffer, Task);
if (EFI_ERROR (Status)) {
break;
}
//
// Data was successfully accessed
//
Position += Len;
UserBuffer += Len;
BufferSize -= Len;
if (IoMode == WRITE_DATA) {
OFile->Dirty = TRUE;
OFile->Archive = TRUE;
}
//
// Make sure no outbound occurred
//
ASSERT (Position <= OFile->FileSize);
}
//
// Update the number of bytes accessed
//
*DataBufferSize -= BufferSize;
return Status;
}
