/** @file
Routines supporting partition discovery and
logical device reading
Copyright (c) 2019 Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <IndustryStandard/Mbr.h>
#include <Uefi/UefiGpt.h>
#include <Library/BaseLib.h>
#include "FatLitePeim.h"
//
// Assumption: 'a' and 'blocksize' are all UINT32 or UINT64.
// If 'a' and 'blocksize' are not the same type, should use DivU64xU32 to calculate.
//
#define EFI_SIZE_TO_BLOCKS(a, blocksize) (((a) / (blocksize)) + (((a) % (blocksize)) ? 1 : 0))
//
// GPT Partition Entry Status
//
typedef struct {
BOOLEAN OutOfRange;
BOOLEAN Overlap;
BOOLEAN OsSpecific;
} EFI_PARTITION_ENTRY_STATUS;
/**
Check if the CRC field in the Partition table header is valid.
@param[in] PartHeader Partition table header structure
@retval TRUE the CRC is valid
@retval FALSE the CRC is invalid
**/
BOOLEAN
PartitionCheckGptHeaderCRC (
IN EFI_PARTITION_TABLE_HEADER *PartHeader
)
{
UINT32 GptHdrCrc;
UINT32 Crc;
GptHdrCrc = PartHeader->Header.CRC32;
//
// Set CRC field to zero when doing calculation
//
PartHeader->Header.CRC32 = 0;
Crc = CalculateCrc32 (PartHeader, PartHeader->Header.HeaderSize);
//
// Restore Header CRC
//
PartHeader->Header.CRC32 = GptHdrCrc;
return (GptHdrCrc == Crc);
}
/**
Check if the CRC field in the Partition table header is valid
for Partition entry array.
@param[in] PartHeader Partition table header structure
@param[in] PartEntry The partition entry array
@retval TRUE the CRC is valid
@retval FALSE the CRC is invalid
**/
BOOLEAN
PartitionCheckGptEntryArrayCRC (
IN EFI_PARTITION_TABLE_HEADER *PartHeader,
IN EFI_PARTITION_ENTRY *PartEntry
)
{
UINT32 Crc;
UINTN Size;
Size = (UINTN)MultU64x32(PartHeader->NumberOfPartitionEntries, PartHeader->SizeOfPartitionEntry);
Crc = CalculateCrc32 (PartEntry, Size);
return (BOOLEAN) (PartHeader->PartitionEntryArrayCRC32 == Crc);
}
/**
The function is used for valid GPT table. Both for Primary and Backup GPT header.
@param[in] PrivateData The global memory map
@param[in] ParentBlockDevNo The parent block device
@param[in] IsPrimaryHeader Indicate to which header will be checked.
@param[in] PartHdr Stores the partition table that is read
@retval TRUE The partition table is valid
@retval FALSE The partition table is not valid
**/
BOOLEAN
PartitionCheckGptHeader (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo,
IN BOOLEAN IsPrimaryHeader,
IN EFI_PARTITION_TABLE_HEADER *PartHdr
)
{
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
EFI_PEI_LBA Lba;
EFI_PEI_LBA AlternateLba;
EFI_PEI_LBA EntryArrayLastLba;
UINT64 PartitionEntryArraySize;
UINT64 PartitionEntryBlockNumb;
UINT32 EntryArraySizeRemainder;
ParentBlockDev = &(PrivateData->BlockDevice[ParentBlockDevNo]);
if (IsPrimaryHeader) {
Lba = PRIMARY_PART_HEADER_LBA;
AlternateLba = ParentBlockDev->LastBlock;
} else {
Lba = ParentBlockDev->LastBlock;
AlternateLba = PRIMARY_PART_HEADER_LBA;
}
if ( (PartHdr->Header.Signature != EFI_PTAB_HEADER_ID) ||
(PartHdr->Header.Revision != 0x00010000) ||
(PartHdr->Header.HeaderSize < 92) ||
(PartHdr->Header.HeaderSize > ParentBlockDev->BlockSize) ||
(!PartitionCheckGptHeaderCRC (PartHdr)) ||
(PartHdr->Header.Reserved != 0)
) {
DEBUG ((DEBUG_ERROR, "Invalid efi partition table header\n"));
return FALSE;
}
//
// | Block0 | Block1 |Block2 ~ FirstUsableLBA - 1|FirstUsableLBA, ... ,LastUsableLBA|LastUsableLBA+1 ~ LastBlock-1| LastBlock |
// |Protective MBR|Primary Header|Entry Array(At Least 16384)| Partition | Entry Array(At Least 16384) |BackUp Header|
//
// 1. Protective MBR is fixed at Block 0.
// 2. Primary Header is fixed at Block 1.
// 3. Backup Header is fixed at LastBlock.
// 4. Must be remain 128*128 bytes for primary entry array.
// 5. Must be remain 128*128 bytes for backup entry array.
// 6. SizeOfPartitionEntry must be equals to 128 * 2^n.
//
if ( (PartHdr->MyLBA != Lba) ||
(PartHdr->AlternateLBA != AlternateLba) ||
(PartHdr->FirstUsableLBA < 2 + EFI_SIZE_TO_BLOCKS (EFI_GPT_PART_ENTRY_MIN_SIZE, ParentBlockDev->BlockSize)) ||
(PartHdr->LastUsableLBA > ParentBlockDev->LastBlock - 1 - EFI_SIZE_TO_BLOCKS (EFI_GPT_PART_ENTRY_MIN_SIZE, ParentBlockDev->BlockSize)) ||
(PartHdr->FirstUsableLBA > PartHdr->LastUsableLBA) ||
(PartHdr->PartitionEntryLBA < 2) ||
(PartHdr->PartitionEntryLBA > ParentBlockDev->LastBlock - 1) ||
(PartHdr->PartitionEntryLBA >= PartHdr->FirstUsableLBA && PartHdr->PartitionEntryLBA <= PartHdr->LastUsableLBA) ||
(PartHdr->SizeOfPartitionEntry%128 != 0) ||
(PartHdr->SizeOfPartitionEntry != sizeof (EFI_PARTITION_ENTRY))
) {
DEBUG ((DEBUG_ERROR, "Invalid efi partition table header\n"));
return FALSE;
}
//
// Ensure the NumberOfPartitionEntries * SizeOfPartitionEntry doesn't overflow.
//
if (PartHdr->NumberOfPartitionEntries > DivU64x32 (MAX_UINTN, PartHdr->SizeOfPartitionEntry)) {
DEBUG ((DEBUG_ERROR, "Memory overflow in GPT Entry Array\n"));
return FALSE;
}
PartitionEntryArraySize = MultU64x32 (PartHdr->NumberOfPartitionEntries, PartHdr->SizeOfPartitionEntry);
EntryArraySizeRemainder = 0;
PartitionEntryBlockNumb = DivU64x32Remainder (PartitionEntryArraySize, ParentBlockDev->BlockSize, &EntryArraySizeRemainder);
if (EntryArraySizeRemainder != 0) {
PartitionEntryBlockNumb++;
}
if (IsPrimaryHeader) {
EntryArrayLastLba = PartHdr->FirstUsableLBA;
} else {
EntryArrayLastLba = ParentBlockDev->LastBlock;
}
//
// Make sure partition entry array not overlaps with partition area or the LastBlock.
//
if (PartHdr->PartitionEntryLBA + PartitionEntryBlockNumb > EntryArrayLastLba) {
DEBUG ((DEBUG_ERROR, "GPT Partition Entry Array Error!\n"));
DEBUG ((DEBUG_ERROR, "PartitionEntryArraySize = %lu.\n", PartitionEntryArraySize));
DEBUG ((DEBUG_ERROR, "PartitionEntryLBA = %lu.\n", PartHdr->PartitionEntryLBA));
DEBUG ((DEBUG_ERROR, "PartitionEntryBlockNumb = %lu.\n", PartitionEntryBlockNumb));
DEBUG ((DEBUG_ERROR, "EntryArrayLastLba = %lu.\n", EntryArrayLastLba));
return FALSE;
}
return TRUE;
}
/**
This function is used to verify each partition in block device.
@param[in] PrivateData The global memory map
@param[in] ParentBlockDevNo The parent block device
@param[in] PartHdr Stores the partition table that is read
@retval TRUE The partition is valid
@retval FALSE The partition is not valid
**/
BOOLEAN
PartitionCheckGptEntryArray (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo,
IN EFI_PARTITION_TABLE_HEADER *PartHdr
)
{
EFI_STATUS Status;
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
PEI_FAT_BLOCK_DEVICE *BlockDevPtr;
UINT64 PartitionEntryArraySize;
UINT64 PartitionEntryBlockNumb;
UINT32 EntryArraySizeRemainder;
EFI_PARTITION_ENTRY *PartitionEntryBuffer;
EFI_PARTITION_ENTRY_STATUS *PartitionEntryStatus;
BOOLEAN Found;
EFI_LBA StartingLBA;
EFI_LBA EndingLBA;
UINTN Index;
UINTN Index1;
UINTN Index2;
EFI_PARTITION_ENTRY *Entry;
PartitionEntryBuffer = NULL;
PartitionEntryStatus = NULL;
ParentBlockDev = &(PrivateData->BlockDevice[ParentBlockDevNo]);
Found = FALSE;
PartitionEntryArraySize = MultU64x32 (PartHdr->NumberOfPartitionEntries, PartHdr->SizeOfPartitionEntry);
EntryArraySizeRemainder = 0;
PartitionEntryBlockNumb = DivU64x32Remainder (PartitionEntryArraySize, ParentBlockDev->BlockSize, &EntryArraySizeRemainder);
if (EntryArraySizeRemainder != 0) {
PartitionEntryBlockNumb++;
}
PartitionEntryArraySize = MultU64x32 (PartitionEntryBlockNumb, ParentBlockDev->BlockSize);
PartitionEntryBuffer = (EFI_PARTITION_ENTRY *) AllocatePages (EFI_SIZE_TO_PAGES ((UINTN)PartitionEntryArraySize));
if (PartitionEntryBuffer == NULL) {
DEBUG ((DEBUG_ERROR, "Allocate memory error!\n"));
goto EXIT;
}
PartitionEntryStatus = (EFI_PARTITION_ENTRY_STATUS *) AllocatePages (EFI_SIZE_TO_PAGES (PartHdr->NumberOfPartitionEntries * sizeof (EFI_PARTITION_ENTRY_STATUS)));
if (PartitionEntryStatus == NULL) {
DEBUG ((DEBUG_ERROR, "Allocate memory error!\n"));
goto EXIT;
}
ZeroMem (PartitionEntryStatus, PartHdr->NumberOfPartitionEntries * sizeof (EFI_PARTITION_ENTRY_STATUS));
Status = FatReadBlock (
PrivateData,
ParentBlockDevNo,
PartHdr->PartitionEntryLBA,
(UINTN)PartitionEntryArraySize,
PartitionEntryBuffer
);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "Read partition entry array error!\n"));
goto EXIT;
}
if (!PartitionCheckGptEntryArrayCRC (PartHdr, PartitionEntryBuffer)) {
DEBUG ((DEBUG_ERROR, "Partition entries CRC check fail\n"));
goto EXIT;
}
for (Index1 = 0; Index1 < PartHdr->NumberOfPartitionEntries; Index1++) {
Entry = (EFI_PARTITION_ENTRY *) ((UINT8 *) PartitionEntryBuffer + Index1 * PartHdr->SizeOfPartitionEntry);
if (CompareGuid (&Entry->PartitionTypeGUID, &gEfiPartTypeUnusedGuid)) {
continue;
}
StartingLBA = Entry->StartingLBA;
EndingLBA = Entry->EndingLBA;
if (StartingLBA > EndingLBA ||
StartingLBA < PartHdr->FirstUsableLBA ||
StartingLBA > PartHdr->LastUsableLBA ||
EndingLBA < PartHdr->FirstUsableLBA ||
EndingLBA > PartHdr->LastUsableLBA
) {
PartitionEntryStatus[Index1].OutOfRange = TRUE;
continue;
}
if ((Entry->Attributes & BIT1) != 0) {
//
// If Bit 1 is set, this indicate that this is an OS specific GUID partition.
//
PartitionEntryStatus[Index1].OsSpecific = TRUE;
}
for (Index2 = Index1 + 1; Index2 < PartHdr->NumberOfPartitionEntries; Index2++) {
Entry = (EFI_PARTITION_ENTRY *) ((UINT8 *) PartitionEntryBuffer + Index2 * PartHdr->SizeOfPartitionEntry);
if (CompareGuid (&Entry->PartitionTypeGUID, &gEfiPartTypeUnusedGuid)) {
continue;
}
if (Entry->EndingLBA >= StartingLBA && Entry->StartingLBA <= EndingLBA) {
//
// This region overlaps with the Index1'th region
//
PartitionEntryStatus[Index1].Overlap = TRUE;
PartitionEntryStatus[Index2].Overlap = TRUE;
continue;
}
}
}
for (Index = 0; Index < PartHdr->NumberOfPartitionEntries; Index++) {
if (CompareGuid (&PartitionEntryBuffer[Index].PartitionTypeGUID, &gEfiPartTypeUnusedGuid)||
PartitionEntryStatus[Index].OutOfRange ||
PartitionEntryStatus[Index].Overlap ||
PartitionEntryStatus[Index].OsSpecific) {
//
// Don't use null EFI Partition Entries, Invalid Partition Entries or OS specific
// partition Entries
//
continue;
}
if (PrivateData->BlockDeviceCount >= PEI_FAT_MAX_BLOCK_DEVICE) {
break;
}
Found = TRUE;
BlockDevPtr = &(PrivateData->BlockDevice[PrivateData->BlockDeviceCount]);
BlockDevPtr->BlockSize = ParentBlockDev->BlockSize;
BlockDevPtr->LastBlock = PartitionEntryBuffer[Index].EndingLBA;
BlockDevPtr->IoAlign = ParentBlockDev->IoAlign;
BlockDevPtr->Logical = TRUE;
BlockDevPtr->PartitionChecked = FALSE;
BlockDevPtr->StartingPos = MultU64x32 (
PartitionEntryBuffer[Index].StartingLBA,
ParentBlockDev->BlockSize
);
BlockDevPtr->ParentDevNo = ParentBlockDevNo;
PrivateData->BlockDeviceCount++;
DEBUG ((DEBUG_INFO, "Find GPT Partition [0x%lx", PartitionEntryBuffer[Index].StartingLBA, BlockDevPtr->LastBlock));
DEBUG ((DEBUG_INFO, ", 0x%lx]\n", BlockDevPtr->LastBlock));
DEBUG ((DEBUG_INFO, " BlockSize %x\n", BlockDevPtr->BlockSize));
}
EXIT:
if (PartitionEntryBuffer != NULL) {
FreePages (PartitionEntryBuffer, EFI_SIZE_TO_PAGES ((UINTN)PartitionEntryArraySize));
}
if (PartitionEntryStatus != NULL) {
FreePages (PartitionEntryStatus, EFI_SIZE_TO_PAGES (PartHdr->NumberOfPartitionEntries * sizeof (EFI_PARTITION_ENTRY_STATUS)));
}
return Found;
}
/**
The function is used to check GPT structure, include GPT header and GPT entry array.
1. Check GPT header.
2. Check partition entry array.
3. Check each partitions.
@param[in] PrivateData The global memory map
@param[in] ParentBlockDevNo The parent block device
@param[in] IsPrimary Indicate primary or backup to be check
@retval TRUE Primary or backup GPT structure is valid.
@retval FALSE Both primary and backup are invalid.
**/
BOOLEAN
PartitionCheckGptStructure (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo,
IN BOOLEAN IsPrimary
)
{
EFI_STATUS Status;
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
EFI_PARTITION_TABLE_HEADER *PartHdr;
EFI_PEI_LBA GptHeaderLBA;
ParentBlockDev = &(PrivateData->BlockDevice[ParentBlockDevNo]);
PartHdr = (EFI_PARTITION_TABLE_HEADER *) PrivateData->BlockData;
if (IsPrimary) {
GptHeaderLBA = PRIMARY_PART_HEADER_LBA;
} else {
GptHeaderLBA = ParentBlockDev->LastBlock;
}
Status = FatReadBlock (
PrivateData,
ParentBlockDevNo,
GptHeaderLBA,
ParentBlockDev->BlockSize,
PartHdr
);
if (EFI_ERROR (Status)) {
return FALSE;
}
if (!PartitionCheckGptHeader (PrivateData, ParentBlockDevNo, IsPrimary, PartHdr)) {
return FALSE;
}
if (!PartitionCheckGptEntryArray (PrivateData, ParentBlockDevNo, PartHdr)) {
return FALSE;
}
return TRUE;
}
/**
This function is used to check protective MBR structure before checking GPT.
@param[in] PrivateData The global memory map
@param[in] ParentBlockDevNo The parent block device
@retval TRUE Valid protective MBR
@retval FALSE Invalid MBR
**/
BOOLEAN
PartitionCheckProtectiveMbr (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo
)
{
EFI_STATUS Status;
MASTER_BOOT_RECORD *ProtectiveMbr;
MBR_PARTITION_RECORD *MbrPartition;
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
UINTN Index;
ProtectiveMbr = (MASTER_BOOT_RECORD *) PrivateData->BlockData;
ParentBlockDev = &(PrivateData->BlockDevice[ParentBlockDevNo]);
//
// Read Protective MBR
//
Status = FatReadBlock (
PrivateData,
ParentBlockDevNo,
0,
ParentBlockDev->BlockSize,
ProtectiveMbr
);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "GPT Error When Read Protective Mbr From Partition!\n"));
return FALSE;
}
if (ProtectiveMbr->Signature != MBR_SIGNATURE) {
DEBUG ((DEBUG_ERROR, "Protective Mbr Signature is invalid!\n"));
return FALSE;
}
//
// The partition define in UEFI Spec Table 17.
// Boot Code, Unique MBR Disk Signature, Unknown.
// These parts will not be used by UEFI, so we skip to check them.
//
for (Index = 0; Index < MAX_MBR_PARTITIONS; Index++) {
MbrPartition = (MBR_PARTITION_RECORD *)&ProtectiveMbr->Partition[Index];
if (MbrPartition->BootIndicator == 0x00 &&
MbrPartition->StartSector == 0x02 &&
MbrPartition->OSIndicator == PMBR_GPT_PARTITION &&
UNPACK_UINT32 (MbrPartition->StartingLBA) == 1
) {
return TRUE;
}
}
DEBUG ((DEBUG_ERROR, "Protective Mbr, All Partition Entry Are Empty!\n"));
return FALSE;
}
/**
This function is used for finding GPT partition on block device.
As follow UEFI spec we should check protective MBR first and then
try to check both primary/backup GPT structures.
@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
FatFindGptPartitions (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo
)
{
BOOLEAN Found;
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
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 exceed FAT_MAX_BLOCK_SIZE\n", ParentBlockDev->BlockSize));
return FALSE;
}
if (!PartitionCheckProtectiveMbr (PrivateData, ParentBlockDevNo)) {
return FALSE;
}
Found = PartitionCheckGptStructure (PrivateData, ParentBlockDevNo, TRUE);
if (!Found) {
DEBUG ((DEBUG_ERROR, "Primary GPT Header Error, Try to Check Backup GPT Header!\n"));
Found = PartitionCheckGptStructure (PrivateData, ParentBlockDevNo, FALSE);
}
if (Found) {
ParentBlockDev->PartitionChecked = TRUE;
}
return Found;
}