mirror of https://github.com/acidanthera/audk.git
315 lines
10 KiB
C
315 lines
10 KiB
C
/** @file
|
|
Decode a hard disk partitioned with the legacy MBR found on most PC's
|
|
|
|
MBR - Master Boot Record is in the first sector of a partitioned hard disk.
|
|
The MBR supports four partitions per disk. The MBR also contains legacy
|
|
code that is not run on an EFI system. The legacy code reads the
|
|
first sector of the active partition into memory and
|
|
|
|
BPB - Boot(?) Parameter Block is in the first sector of a FAT file system.
|
|
The BPB contains information about the FAT file system. The BPB is
|
|
always on the first sector of a media. The first sector also contains
|
|
the legacy boot strap code.
|
|
|
|
Copyright (c) 2006 - 2008, Intel Corporation. <BR>
|
|
All rights reserved. This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD License
|
|
which accompanies this distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
|
|
#include "Partition.h"
|
|
|
|
/**
|
|
Test to see if the Mbr buffer is a valid MBR.
|
|
|
|
@param Mbr Parent Handle.
|
|
@param LastLba Last Lba address on the device.
|
|
|
|
@retval TRUE Mbr is a Valid MBR.
|
|
@retval FALSE Mbr is not a Valid MBR.
|
|
|
|
**/
|
|
STATIC
|
|
BOOLEAN
|
|
PartitionValidMbr (
|
|
IN MASTER_BOOT_RECORD *Mbr,
|
|
IN EFI_LBA LastLba
|
|
)
|
|
{
|
|
UINT32 StartingLBA;
|
|
UINT32 EndingLBA;
|
|
UINT32 NewEndingLBA;
|
|
INTN Index1;
|
|
INTN Index2;
|
|
BOOLEAN MbrValid;
|
|
|
|
if (Mbr->Signature != MBR_SIGNATURE) {
|
|
return FALSE;
|
|
}
|
|
//
|
|
// The BPB also has this signature, so it can not be used alone.
|
|
//
|
|
MbrValid = FALSE;
|
|
for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {
|
|
if (Mbr->Partition[Index1].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {
|
|
continue;
|
|
}
|
|
|
|
MbrValid = TRUE;
|
|
StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);
|
|
EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;
|
|
if (EndingLBA > LastLba) {
|
|
//
|
|
// Compatibility Errata:
|
|
// Some systems try to hide drive space with their INT 13h driver
|
|
// This does not hide space from the OS driver. This means the MBR
|
|
// that gets created from DOS is smaller than the MBR created from
|
|
// a real OS (NT & Win98). This leads to BlockIo->LastBlock being
|
|
// wrong on some systems FDISKed by the OS.
|
|
//
|
|
// return FALSE since no block devices on a system are implemented
|
|
// with INT 13h
|
|
//
|
|
return FALSE;
|
|
}
|
|
|
|
for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {
|
|
if (Mbr->Partition[Index2].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {
|
|
continue;
|
|
}
|
|
|
|
NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;
|
|
if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {
|
|
//
|
|
// This region overlaps with the Index1'th region
|
|
//
|
|
return FALSE;
|
|
}
|
|
}
|
|
}
|
|
//
|
|
// None of the regions overlapped so MBR is O.K.
|
|
//
|
|
return MbrValid;
|
|
}
|
|
|
|
|
|
/**
|
|
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;
|
|
|
|
Mbr = NULL;
|
|
Found = EFI_NOT_FOUND;
|
|
|
|
Mbr = AllocatePool (BlockIo->Media->BlockSize);
|
|
if (Mbr == NULL) {
|
|
goto Done;
|
|
}
|
|
|
|
Status = BlockIo->ReadBlocks (
|
|
BlockIo,
|
|
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 (!EfiIsDevicePathEnd (DevicePathNode)) {
|
|
LastDevicePathNode = DevicePathNode;
|
|
DevicePathNode = EfiNextDevicePathNode (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 (UINT32));
|
|
|
|
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 = BlockIo->ReadBlocks (
|
|
BlockIo,
|
|
BlockIo->Media->MediaId,
|
|
ExtMbrStartingLba,
|
|
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;
|
|
}
|