+++ /dev/null
-/*++\r
-\r
-Copyright (c) 2006 - 2007, Intel Corporation \r
-All rights reserved. This program and the accompanying materials \r
-are licensed and made available under the terms and conditions of the BSD License \r
-which accompanies this distribution. The full text of the license may be found at \r
-http://opensource.org/licenses/bsd-license.php \r
- \r
-THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
-WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
-\r
-Module Name:\r
-\r
- Mbr.c\r
- \r
-Abstract:\r
-\r
- Decode a hard disk partitioned with the legacy MBR found on most PC's\r
-\r
- MBR - Master Boot Record is in the first sector of a partitioned hard disk.\r
- The MBR supports four partitions per disk. The MBR also contains legacy\r
- code that is not run on an EFI system. The legacy code reads the \r
- first sector of the active partition into memory and \r
-\r
- BPB - Boot(?) Parameter Block is in the first sector of a FAT file system. \r
- The BPB contains information about the FAT file system. The BPB is \r
- always on the first sector of a media. The first sector also contains\r
- the legacy boot strap code.\r
-\r
---*/\r
-\r
-#include "Partition.h"\r
-\r
-STATIC\r
-BOOLEAN\r
-PartitionValidMbr (\r
- IN MASTER_BOOT_RECORD *Mbr,\r
- IN EFI_LBA LastLba\r
- )\r
-/*++\r
-\r
-Routine Description:\r
- Test to see if the Mbr buffer is a valid MBR\r
-\r
-Arguments: \r
- Mbr - Parent Handle \r
- LastLba - Last Lba address on the device.\r
-\r
-Returns:\r
- TRUE - Mbr is a Valid MBR\r
- FALSE - Mbr is not a Valid MBR\r
-\r
---*/\r
-{\r
- UINT32 StartingLBA;\r
- UINT32 EndingLBA;\r
- UINT32 NewEndingLBA;\r
- INTN Index1;\r
- INTN Index2;\r
- BOOLEAN MbrValid;\r
-\r
- if (Mbr->Signature != MBR_SIGNATURE) {\r
- return FALSE;\r
- }\r
- //\r
- // The BPB also has this signature, so it can not be used alone.\r
- //\r
- MbrValid = FALSE;\r
- for (Index1 = 0; Index1 < MAX_MBR_PARTITIONS; Index1++) {\r
- if (Mbr->Partition[Index1].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) == 0) {\r
- continue;\r
- }\r
-\r
- MbrValid = TRUE;\r
- StartingLBA = UNPACK_UINT32 (Mbr->Partition[Index1].StartingLBA);\r
- EndingLBA = StartingLBA + UNPACK_UINT32 (Mbr->Partition[Index1].SizeInLBA) - 1;\r
- if (EndingLBA > LastLba) {\r
- //\r
- // Compatibility Errata:\r
- // Some systems try to hide drive space with their INT 13h driver\r
- // This does not hide space from the OS driver. This means the MBR\r
- // that gets created from DOS is smaller than the MBR created from\r
- // a real OS (NT & Win98). This leads to BlockIo->LastBlock being\r
- // wrong on some systems FDISKed by the OS.\r
- //\r
- // return FALSE since no block devices on a system are implemented\r
- // with INT 13h\r
- //\r
- return FALSE;\r
- }\r
-\r
- for (Index2 = Index1 + 1; Index2 < MAX_MBR_PARTITIONS; Index2++) {\r
- if (Mbr->Partition[Index2].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) == 0) {\r
- continue;\r
- }\r
-\r
- NewEndingLBA = UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) + UNPACK_UINT32 (Mbr->Partition[Index2].SizeInLBA) - 1;\r
- if (NewEndingLBA >= StartingLBA && UNPACK_UINT32 (Mbr->Partition[Index2].StartingLBA) <= EndingLBA) {\r
- //\r
- // This region overlaps with the Index1'th region\r
- //\r
- return FALSE;\r
- }\r
- }\r
- }\r
- //\r
- // Non of the regions overlapped so MBR is O.K.\r
- //\r
- return MbrValid;\r
-}\r
-\r
-EFI_STATUS\r
-PartitionInstallMbrChildHandles (\r
- IN EFI_DRIVER_BINDING_PROTOCOL *This,\r
- IN EFI_HANDLE Handle,\r
- IN EFI_DISK_IO_PROTOCOL *DiskIo,\r
- IN EFI_BLOCK_IO_PROTOCOL *BlockIo,\r
- IN EFI_DEVICE_PATH_PROTOCOL *DevicePath\r
- )\r
-/*++\r
-\r
-Routine Description:\r
- Install child handles if the Handle supports MBR format.\r
-\r
-Arguments: \r
- This - Calling context.\r
- Handle - Parent Handle \r
- DiskIo - Parent DiskIo interface\r
- BlockIo - Parent BlockIo interface\r
- DevicePath - Parent Device Path\r
-\r
-Returns:\r
- EFI_SUCCESS - If a child handle was added\r
- EFI_MEDIA_CHANGED - Media changed Detected\r
- !EFI_SUCCESS - Not found MBR partition.\r
-\r
---*/\r
-{\r
- EFI_STATUS Status;\r
- MASTER_BOOT_RECORD *Mbr;\r
- UINT32 ExtMbrStartingLba;\r
- UINTN Index;\r
- HARDDRIVE_DEVICE_PATH HdDev;\r
- HARDDRIVE_DEVICE_PATH ParentHdDev;\r
- EFI_STATUS Found;\r
- UINT32 PartitionNumber;\r
- EFI_DEVICE_PATH_PROTOCOL *DevicePathNode;\r
- EFI_DEVICE_PATH_PROTOCOL *LastDevicePathNode;\r
-\r
- Mbr = NULL;\r
- Found = EFI_NOT_FOUND;\r
-\r
- Mbr = AllocatePool (BlockIo->Media->BlockSize);\r
- if (Mbr == NULL) {\r
- goto Done;\r
- }\r
-\r
- Status = BlockIo->ReadBlocks (\r
- BlockIo,\r
- BlockIo->Media->MediaId,\r
- 0,\r
- BlockIo->Media->BlockSize,\r
- Mbr\r
- );\r
- if (EFI_ERROR (Status)) {\r
- Found = Status;\r
- goto Done;\r
- }\r
- if (!PartitionValidMbr (Mbr, BlockIo->Media->LastBlock)) {\r
- goto Done;\r
- }\r
- //\r
- // We have a valid mbr - add each partition\r
- //\r
- //\r
- // Get starting and ending LBA of the parent block device.\r
- //\r
- LastDevicePathNode = NULL;\r
- ZeroMem (&ParentHdDev, sizeof (ParentHdDev));\r
- DevicePathNode = DevicePath;\r
- while (!EfiIsDevicePathEnd (DevicePathNode)) {\r
- LastDevicePathNode = DevicePathNode;\r
- DevicePathNode = EfiNextDevicePathNode (DevicePathNode);\r
- }\r
-\r
- if (LastDevicePathNode != NULL) {\r
- if (DevicePathType (LastDevicePathNode) == MEDIA_DEVICE_PATH &&\r
- DevicePathSubType (LastDevicePathNode) == MEDIA_HARDDRIVE_DP\r
- ) {\r
- CopyMem (&ParentHdDev, LastDevicePathNode, sizeof (ParentHdDev));\r
- } else {\r
- LastDevicePathNode = NULL;\r
- }\r
- }\r
-\r
- PartitionNumber = 1;\r
-\r
- ZeroMem (&HdDev, sizeof (HdDev));\r
- HdDev.Header.Type = MEDIA_DEVICE_PATH;\r
- HdDev.Header.SubType = MEDIA_HARDDRIVE_DP;\r
- SetDevicePathNodeLength (&HdDev.Header, sizeof (HdDev));\r
- HdDev.MBRType = MBR_TYPE_PCAT;\r
- HdDev.SignatureType = SIGNATURE_TYPE_MBR;\r
-\r
- if (LastDevicePathNode == NULL) {\r
- //\r
- // This is a MBR, add each partition\r
- //\r
- for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {\r
- if (Mbr->Partition[Index].OSIndicator == 0x00 || UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA) == 0) {\r
- //\r
- // Don't use null MBR entries\r
- //\r
- continue;\r
- }\r
-\r
- if (Mbr->Partition[Index].OSIndicator == PMBR_GPT_PARTITION) {\r
- //\r
- // This is the guard MBR for the GPT. If you ever see a GPT disk with zero partitions you can get here.\r
- // We can not produce an MBR BlockIo for this device as the MBR spans the GPT headers. So formating \r
- // this BlockIo would corrupt the GPT structures and require a recovery that would corrupt the format\r
- // that corrupted the GPT partition. \r
- //\r
- continue;\r
- }\r
-\r
- HdDev.PartitionNumber = PartitionNumber ++;\r
- HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[Index].StartingLBA);\r
- HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[Index].SizeInLBA);\r
- CopyMem (HdDev.Signature, &(Mbr->UniqueMbrSignature[0]), sizeof (UINT32));\r
-\r
- Status = PartitionInstallChildHandle (\r
- This,\r
- Handle,\r
- DiskIo,\r
- BlockIo,\r
- DevicePath,\r
- (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
- HdDev.PartitionStart,\r
- HdDev.PartitionStart + HdDev.PartitionSize - 1,\r
- MBR_SIZE,\r
- (BOOLEAN) (Mbr->Partition[Index].OSIndicator == EFI_PARTITION)\r
- );\r
-\r
- if (!EFI_ERROR (Status)) {\r
- Found = EFI_SUCCESS;\r
- }\r
- }\r
- } else {\r
- //\r
- // It's an extended partition. Follow the extended partition\r
- // chain to get all the logical drives\r
- //\r
- ExtMbrStartingLba = 0;\r
-\r
- do {\r
-\r
- Status = BlockIo->ReadBlocks (\r
- BlockIo,\r
- BlockIo->Media->MediaId,\r
- ExtMbrStartingLba,\r
- BlockIo->Media->BlockSize,\r
- Mbr\r
- );\r
- if (EFI_ERROR (Status)) {\r
- Found = Status;\r
- goto Done;\r
- }\r
-\r
- if (Mbr->Partition[0].OSIndicator == 0) {\r
- break;\r
- }\r
-\r
- if ((Mbr->Partition[0].OSIndicator == EXTENDED_DOS_PARTITION) ||\r
- (Mbr->Partition[0].OSIndicator == EXTENDED_WINDOWS_PARTITION)) {\r
- ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA);\r
- continue;\r
- }\r
- HdDev.PartitionNumber = PartitionNumber ++;\r
- HdDev.PartitionStart = UNPACK_UINT32 (Mbr->Partition[0].StartingLBA) + ExtMbrStartingLba + ParentHdDev.PartitionStart;\r
- HdDev.PartitionSize = UNPACK_UINT32 (Mbr->Partition[0].SizeInLBA);\r
- if ((HdDev.PartitionStart + HdDev.PartitionSize - 1 >= ParentHdDev.PartitionStart + ParentHdDev.PartitionSize) ||\r
- (HdDev.PartitionStart <= ParentHdDev.PartitionStart)) {\r
- break;\r
- }\r
-\r
- //\r
- // The signature in EBR(Extended Boot Record) should always be 0.\r
- //\r
- *((UINT32 *) &HdDev.Signature[0]) = 0;\r
-\r
- Status = PartitionInstallChildHandle (\r
- This,\r
- Handle,\r
- DiskIo,\r
- BlockIo,\r
- DevicePath,\r
- (EFI_DEVICE_PATH_PROTOCOL *) &HdDev,\r
- HdDev.PartitionStart - ParentHdDev.PartitionStart,\r
- HdDev.PartitionStart - ParentHdDev.PartitionStart + HdDev.PartitionSize - 1,\r
- MBR_SIZE,\r
- (BOOLEAN) (Mbr->Partition[0].OSIndicator == EFI_PARTITION)\r
- );\r
- if (!EFI_ERROR (Status)) {\r
- Found = EFI_SUCCESS;\r
- }\r
-\r
- if ((Mbr->Partition[1].OSIndicator != EXTENDED_DOS_PARTITION) &&\r
- (Mbr->Partition[1].OSIndicator != EXTENDED_WINDOWS_PARTITION)\r
- ) {\r
- break;\r
- }\r
-\r
- ExtMbrStartingLba = UNPACK_UINT32 (Mbr->Partition[1].StartingLBA);\r
- //\r
- // Don't allow partition to be self referencing\r
- //\r
- if (ExtMbrStartingLba == 0) {\r
- break;\r
- }\r
- } while (ExtMbrStartingLba < ParentHdDev.PartitionSize);\r
- }\r
-\r
-Done:\r
- FreePool (Mbr);\r
-\r
- return Found;\r
-}\r
projects / mirror_edk2.git / blobdiff