/**
Install child handles if the Handle supports MBR format.
@param This Calling context.
@param Handle Parent Handle.
@param DiskIo Parent DiskIo interface.
@param BlockIo Parent BlockIo interface.
@param DevicePath Parent Device Path.
@retval EFI_SUCCESS A child handle was added.
@retval EFI_MEDIA_CHANGED Media change was detected.
@retval Others MBR partition was not found.
**/
EFI_STATUS
PartitionInstallMbrChildHandles (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Handle,
IN EFI_DISK_IO_PROTOCOL *DiskIo,
IN EFI_BLOCK_IO_PROTOCOL *BlockIo,
IN EFI_DEVICE_PATH_PROTOCOL *DevicePath
)
{
EFI_STATUS Status;
MASTER_BOOT_RECORD *Mbr;
UINT32 ExtMbrStartingLba;
UINTN Index;
HARDDRIVE_DEVICE_PATH HdDev;
HARDDRIVE_DEVICE_PATH ParentHdDev;
EFI_STATUS Found;
UINT32 PartitionNumber;
EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;
EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;
Found = EFI_NOT_FOUND;
Mbr = AllocatePool (BlockIo->Media->BlockSize);
if (Mbr == NULL) {
return Found;
}
Status = DiskIo->ReadDisk (
DiskIo,
BlockIo->Media->MediaId,
0,
BlockIo->Media->BlockSize,
Mbr
);
if (EFI_ERROR (Status)) {
Found = Status;
goto Done;
}
if (!PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {
goto Done;
}
//
// We have a valid mbr - add each partition
//
//
// Get starting and ending LBA of the parent block device.
//
LastDevicePathNode = NULL;
ZeroMem (&ParentHdDev, sizeof (ParentHdDev));
DevicePathNode = DevicePath;
while (!IsDevicePathEnd (DevicePathNode)) {
LastDevicePathNode = DevicePathNode;
DevicePathNode = NextDevicePathNode (DevicePathNode);
}
if (LastDevicePathNode != NULL) {
if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&
DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP
) {
CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));
} else {
LastDevicePathNode = NULL;
}
}
PartitionNumber = 1;
ZeroMem (&HdDev, sizeof (HdDev));
HdDev.Header.Type = MEDIA_DEVICE_PATH;
HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;
SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));
HdDev.MBRType = MBR_TYPE_PCAT;
HdDev.SignatureType = SIGNATURE_TYPE_MBR;
if (LastDevicePathNode == NULL) {
//
// This is a MBR, add each partition
//
for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {
if (Mbr->Partition[Index].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {
//
// Don't use null MBR entries
//
continue;
}
if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {
//
// This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.
// We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating
// this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format
// that corrupted the GPT partition.
//
continue;
}
HdDev.PartitionNumber = PartitionNumber ++;
HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);
HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);
CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (Mbr->UniqueMbrSignature));
Status = PartitionInstallChildHandle (
This,
Handle,
DiskIo,
BlockIo,
DevicePath,
(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,
HdDev.PartitionStart,
HdDev.PartitionStart + HdDev.PartitionSize - 1,
MBR_SIZE,
(BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)
);
if (!EFI_ERROR (Status)) {
Found = EFI_SUCCESS;
}
}
} else {
//
// It's an extended partition. Follow the extended partition
// chain to get all the logical drives
//
ExtMbrStartingLba = 0;
do {
Status = DiskIo->ReadDisk (
DiskIo,
BlockIo->Media->MediaId,
MultU64x32 (ExtMbrStartingLba, BlockIo->Media->BlockSize),
BlockIo->Media->BlockSize,
Mbr
);
if (EFI_ERROR (Status)) {
Found = Status;
goto Done;
}
if (UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA) == 0) {
break;
}
if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) ||
(Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {
ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);
continue;
}
HdDev.PartitionNumber = PartitionNumber ++;
HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;
HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);
if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) ||
(HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {
break;
}
//
// The signature in EBR(Extended Boot Record) should always be 0.
//
*((UINT32 *) &HdDev.Signature[0]) = 0;
Status = PartitionInstallChildHandle (
This,
Handle,
DiskIo,
BlockIo,
DevicePath,
(EFI_DEVICE_PATH_PROTOCOL *) &HdDev,
HdDev.PartitionStart - ParentHdDev.PartitionStart,
HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,
MBR_SIZE,
(BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)
);
if (!EFI_ERROR (Status)) {
Found = EFI_SUCCESS;
}
if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&
(Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)
) {
break;
}
ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);
//
// Don't allow partition to be self referencing
//
if (ExtMbrStartingLba == 0) {
break;
}
} while (ExtMbrStartingLba < ParentHdDev.PartitionSize);
}
Done:
FreePool (Mbr);
return Found;
}
/**
This function finds Mbr partitions. Main algorithm
is ported from DXE partition driver.
@param PrivateData The global memory map
@param ParentBlockDevNo The parent block device
@retval TRUE New partitions are detected and logical block devices
are added to block device array
@retval FALSE No New partitions are added;
**/
BOOLEAN
FatFindMbrPartitions (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo
)
{
EFI_STATUS Status;
MASTER_BOOT_RECORD *Mbr;
UINTN Index;
BOOLEAN Found;
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
PEI_FAT_BLOCK_DEVICE *BlockDev;
if (ParentBlockDevNo > PEI_FAT_MAX_BLOCK_DEVICE - 1) {
return FALSE;
}
ParentBlockDev = &(PrivateData->BlockDevice[ParentBlockDevNo]);
Found = FALSE;
Mbr = (MASTER_BOOT_RECORD *) PrivateData->BlockData;
Status = FatReadBlock (
PrivateData,
ParentBlockDevNo,
0,
ParentBlockDev->BlockSize,
Mbr
);
if (EFI_ERROR (Status) || !PartitionValidMbr (Mbr, ParentBlockDev->LastBlock)) {
goto Done;
}
//
// We have a valid mbr - add each partition
//
for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {
if (Mbr->Partition[Index].OSIndicator == 0x00 || UNPACK_INT32 (Mbr->Partition[Index].SizeInLBA) == 0) {
//
// Don't use null MBR entries
//
continue;
}
//
// Register this partition
//
if (PrivateData->BlockDeviceCount < PEI_FAT_MAX_BLOCK_DEVICE) {
Found = TRUE;
BlockDev = &(PrivateData->BlockDevice[PrivateData->BlockDeviceCount]);
BlockDev->BlockSize = MBR_SIZE;
BlockDev->LastBlock = UNPACK_INT32 (Mbr->Partition[Index].SizeInLBA) - 1;
BlockDev->IoAlign = ParentBlockDev->IoAlign;
BlockDev->Logical = TRUE;
BlockDev->PartitionChecked = FALSE;
BlockDev->StartingPos = MultU64x32 (
UNPACK_INT32 (Mbr->Partition[Index].StartingLBA),
ParentBlockDev->BlockSize
);
BlockDev->ParentDevNo = ParentBlockDevNo;
PrivateData->BlockDeviceCount++;
}
}
Done:
ParentBlockDev->PartitionChecked = TRUE;
return Found;
}
