From 6aac772c560db55fd82c1e19767036a6f70144a2 Mon Sep 17 00:00:00 2001 From: Chen A Chen Date: Wed, 16 Jan 2019 16:13:31 +0800 Subject: FatPkg: Break down Part.c file. BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1470 Break down partition parsing logic to 2 parts, Eltorito and MBR. Cc: Ruiyu Ni Cc: Zhang Chao B Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Chen A Chen Reviewed-by: Hao Wu --- FatPkg/FatPei/Mbr.c | 181 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 181 insertions(+) create mode 100644 FatPkg/FatPei/Mbr.c (limited to 'FatPkg/FatPei/Mbr.c') diff --git a/FatPkg/FatPei/Mbr.c b/FatPkg/FatPei/Mbr.c new file mode 100644 index 0000000..acad6e7 --- /dev/null +++ b/FatPkg/FatPei/Mbr.c @@ -0,0 +1,181 @@ +/** @file + Routines supporting partition discovery and + logical device reading + +Copyright (c) 2006 - 2019, Intel Corporation. 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 +#include "FatLitePeim.h" + +/** + Test to see if the Mbr buffer is a valid MBR + + @param[in] Mbr Parent Handle + @param[in] LastLba Last Lba address on the device. + + @retval TRUE Mbr is a Valid MBR + @retval FALSE Mbr is not a Valid MBR + +**/ +BOOLEAN +PartitionValidMbr ( + IN MASTER_BOOT_RECORD *Mbr, + IN EFI_PEI_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) { + // + // Compatability Errata: + // Some systems try to hide drive space with thier 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 Because 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_INT32 (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; + } + } + } + // + // Non of the regions overlapped so MBR is O.K. + // + return MbrValid; +} + +/** + This function finds Mbr partitions. Main algorithm + is ported from DXE partition driver. + + @param[in] PrivateData The global memory map + @param[in] 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]); + + if (ParentBlockDev->BlockSize > PEI_FAT_MAX_BLOCK_SIZE) { + DEBUG((DEBUG_ERROR, "Device BlockSize %x exceeds FAT_MAX_BLOCK_SIZE\n", ParentBlockDev->BlockSize)); + return FALSE; + } + + 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; +} -- cgit v1.1