/**
Gets the next cluster in the cluster chain
@param PrivateData Global memory map for accessing global variables
@param Volume The volume
@param Cluster The cluster
@param NextCluster The cluster number of the next cluster
@retval EFI_SUCCESS The address is got
@retval EFI_INVALID_PARAMETER ClusterNo exceeds the MaxCluster of the volume.
@retval EFI_DEVICE_ERROR Read disk error
**/
EFI_STATUS
FatGetNextCluster (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN PEI_FAT_VOLUME *Volume,
IN UINT32 Cluster,
OUT UINT32 *NextCluster
)
{
EFI_STATUS Status;
UINT64 FatEntryPos;
UINT32 Dummy;
*NextCluster = 0;
if (Volume->FatType == Fat32) {
FatEntryPos = Volume->FatPos + MultU64x32 (4, Cluster);
Status = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 4, NextCluster);
*NextCluster &= 0x0fffffff;
//
// Pad high bits for our FAT_CLUSTER_... macro definitions to work
//
if ((*NextCluster) >= 0x0ffffff7) {
*NextCluster |= (-1 &~0xf);
}
} else if (Volume->FatType == Fat16) {
FatEntryPos = Volume->FatPos + MultU64x32 (2, Cluster);
Status = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 2, NextCluster);
//
// Pad high bits for our FAT_CLUSTER_... macro definitions to work
//
if ((*NextCluster) >= 0xfff7) {
*NextCluster |= (-1 &~0xf);
}
} else {
FatEntryPos = Volume->FatPos + DivU64x32Remainder (MultU64x32 (3, Cluster), 2, &Dummy);
Status = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 2, NextCluster);
if ((Cluster & 0x01) != 0) {
*NextCluster = (*NextCluster) >> 4;
} else {
/**
Reads a block of data from the block device by calling
underlying Block I/O service.
@param PrivateData Global memory map for accessing global variables
@param BlockDeviceNo The index for the block device number.
@param Lba The logic block address to read data from.
@param BufferSize The size of data in byte to read.
@param Buffer The buffer of the
@retval EFI_DEVICE_ERROR The specified block device number exceeds the maximum
device number.
@retval EFI_DEVICE_ERROR The maximum address has exceeded the maximum address
of the block device.
**/
EFI_STATUS
FatReadBlock (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN BlockDeviceNo,
IN EFI_PEI_LBA Lba,
IN UINTN BufferSize,
OUT VOID *Buffer
)
{
EFI_STATUS Status;
PEI_FAT_BLOCK_DEVICE *BlockDev;
if (BlockDeviceNo > PEI_FAT_MAX_BLOCK_DEVICE - 1) {
return EFI_DEVICE_ERROR;
}
Status = EFI_SUCCESS;
BlockDev = &(PrivateData->BlockDevice[BlockDeviceNo]);
if (BufferSize > MultU64x32 (BlockDev->LastBlock - Lba + 1, BlockDev->BlockSize)) {
return EFI_DEVICE_ERROR;
}
if (!BlockDev->Logical) {
//
// Status = BlockDev->ReadFunc
// (PrivateData->PeiServices, BlockDev->PhysicalDevNo, Lba, BufferSize, Buffer);
//
Status = BlockDev->BlockIo->ReadBlocks (
(EFI_PEI_SERVICES **) GetPeiServicesTablePointer (),
BlockDev->BlockIo,
BlockDev->PhysicalDevNo,
Lba,
BufferSize,
Buffer
);
} else {
Status = FatReadDisk (
PrivateData,
BlockDev->ParentDevNo,
BlockDev->StartingPos + MultU64x32 (Lba, BlockDev->BlockSize),
BufferSize,
Buffer
);
}
return Status;
}
/**
Check if there is a valid FAT in the corresponding Block device
of the volume and if yes, fill in the relevant fields for the
volume structure. Note there should be a valid Block device number
already set.
@param PrivateData Global memory map for accessing global
variables.
@param Volume On input, the BlockDeviceNumber field of the
Volume should be a valid value. On successful
output, all fields except the VolumeNumber
field is initialized.
@retval EFI_SUCCESS A FAT is found and the volume structure is
initialized.
@retval EFI_NOT_FOUND There is no FAT on the corresponding device.
@retval EFI_DEVICE_ERROR There is something error while accessing device.
**/
EFI_STATUS
FatGetBpbInfo (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN OUT PEI_FAT_VOLUME *Volume
)
{
EFI_STATUS Status;
PEI_FAT_BOOT_SECTOR Bpb;
PEI_FAT_BOOT_SECTOR_EX BpbEx;
UINT32 Sectors;
UINT32 SectorsPerFat;
UINT32 RootDirSectors;
UINT64 FatLba;
UINT64 RootLba;
UINT64 FirstClusterLba;
//
// Read in the BPB
//
Status = FatReadDisk (
PrivateData,
Volume->BlockDeviceNo,
0,
sizeof (PEI_FAT_BOOT_SECTOR_EX),
&BpbEx
);
if (EFI_ERROR (Status)) {
return Status;
}
CopyMem (
(UINT8 *) (&Bpb),
(UINT8 *) (&BpbEx),
sizeof (PEI_FAT_BOOT_SECTOR)
);
Volume->FatType = FatUnknown;
Sectors = Bpb.Sectors;
if (Sectors == 0) {
Sectors = Bpb.LargeSectors;
}
SectorsPerFat = Bpb.SectorsPerFat;
if (SectorsPerFat == 0) {
SectorsPerFat = BpbEx.LargeSectorsPerFat;
Volume->FatType = Fat32;
}
//
// Filter out those not a FAT
//
if (Bpb.Ia32Jump[0] != 0xe9 && Bpb.Ia32Jump[0] != 0xeb && Bpb.Ia32Jump[0] != 0x49) {
return EFI_NOT_FOUND;
}
if (Bpb.ReservedSectors == 0 || Bpb.NoFats == 0 || Sectors == 0) {
return EFI_NOT_FOUND;
}
if (Bpb.SectorsPerCluster != 1 &&
Bpb.SectorsPerCluster != 2 &&
Bpb.SectorsPerCluster != 4 &&
Bpb.SectorsPerCluster != 8 &&
Bpb.SectorsPerCluster != 16 &&
Bpb.SectorsPerCluster != 32 &&
Bpb.SectorsPerCluster != 64 &&
Bpb.SectorsPerCluster != 128
) {
return EFI_NOT_FOUND;
}
if (Volume->FatType == Fat32 && (SectorsPerFat == 0 || BpbEx.FsVersion != 0)) {
return EFI_NOT_FOUND;
}
if (Bpb.Media != 0xf0 &&
Bpb.Media != 0xf8 &&
Bpb.Media != 0xf9 &&
Bpb.Media != 0xfb &&
Bpb.Media != 0xfc &&
Bpb.Media != 0xfd &&
Bpb.Media != 0xfe &&
Bpb.Media != 0xff &&
//
// FujitsuFMR
//
Bpb.Media != 0x00 &&
Bpb.Media != 0x01 &&
Bpb.Media != 0xfa
) {
return EFI_NOT_FOUND;
}
if (Volume->FatType != Fat32 && Bpb.RootEntries == 0) {
return EFI_NOT_FOUND;
}
//
// If this is fat32, refuse to mount mirror-disabled volumes
//
if (Volume->FatType == Fat32 && ((BpbEx.ExtendedFlags & 0x80) != 0)) {
return EFI_NOT_FOUND;
}
//
// Fill in the volume structure fields
// (Sectors & SectorsPerFat is computed earlier already)
//
Volume->ClusterSize = Bpb.SectorSize * Bpb.SectorsPerCluster;
Volume->RootEntries = Bpb.RootEntries;
Volume->SectorSize = Bpb.SectorSize;
RootDirSectors = ((Volume->RootEntries * sizeof (FAT_DIRECTORY_ENTRY)) + (Volume->SectorSize - 1)) / Volume->SectorSize;
FatLba = Bpb.ReservedSectors;
RootLba = Bpb.NoFats * SectorsPerFat + FatLba;
FirstClusterLba = RootLba + RootDirSectors;
Volume->VolumeSize = MultU64x32 (Sectors, Volume->SectorSize);
Volume->FatPos = MultU64x32 (FatLba, Volume->SectorSize);
Volume->RootDirPos = MultU64x32 (RootLba, Volume->SectorSize);
Volume->FirstClusterPos = MultU64x32 (FirstClusterLba, Volume->SectorSize);
Volume->MaxCluster = (UINT32) (Sectors - FirstClusterLba) / Bpb.SectorsPerCluster;
Volume->RootDirCluster = BpbEx.RootDirFirstCluster;
//
// If this is not a fat32, determine if it's a fat16 or fat12
//
if (Volume->FatType != Fat32) {
if (Volume->MaxCluster >= 65525) {
return EFI_NOT_FOUND;
}
Volume->FatType = Volume->MaxCluster < 4085 ? Fat12 : Fat16;
}
return EFI_SUCCESS;
}
