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audk/FatPkg/FatPei/Part.c

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/** @file
Routines supporting partition discovery and
logical device reading
Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
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 <IndustryStandard/Mbr.h>
#include <IndustryStandard/ElTorito.h>
#include "FatLitePeim.h"
/**
This function finds Eltorito 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
FatFindEltoritoPartitions (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo
);
/**
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
);
/**
This function finds partitions (logical devices) in physical block devices.
@param PrivateData Global memory map for accessing global variables.
**/
VOID
FatFindPartitions (
IN PEI_FAT_PRIVATE_DATA *PrivateData
)
{
BOOLEAN Found;
UINTN Index;
do {
Found = FALSE;
for (Index = 0; Index < PrivateData->BlockDeviceCount; Index++) {
if (!PrivateData->BlockDevice[Index].PartitionChecked) {
Found = FatFindMbrPartitions (PrivateData, Index);
if (!Found) {
Found = FatFindEltoritoPartitions (PrivateData, Index);
}
}
}
} while (Found && PrivateData->BlockDeviceCount <= PEI_FAT_MAX_BLOCK_DEVICE);
}
/**
This function finds Eltorito 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
FatFindEltoritoPartitions (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN UINTN ParentBlockDevNo
)
{
EFI_STATUS Status;
BOOLEAN Found;
PEI_FAT_BLOCK_DEVICE *BlockDev;
PEI_FAT_BLOCK_DEVICE *ParentBlockDev;
UINT32 VolDescriptorLba;
UINT32 Lba;
CDROM_VOLUME_DESCRIPTOR *VolDescriptor;
ELTORITO_CATALOG *Catalog;
UINTN Check;
UINTN Index;
UINTN MaxIndex;
UINT16 *CheckBuffer;
UINT32 SubBlockSize;
UINT32 SectorCount;
UINT32 VolSpaceSize;
if (ParentBlockDevNo > PEI_FAT_MAX_BLOCK_DEVICE - 1) {
return FALSE;
}
Found = FALSE;
ParentBlockDev = &(PrivateData->BlockDevice[ParentBlockDevNo]);
VolSpaceSize = 0;
//
// CD_ROM has the fixed block size as 2048 bytes
//
if (ParentBlockDev->BlockSize != 2048) {
return FALSE;
}
VolDescriptor = (CDROM_VOLUME_DESCRIPTOR *) PrivateData->BlockData;
Catalog = (ELTORITO_CATALOG *) VolDescriptor;
//
// the ISO-9660 volume descriptor starts at 32k on the media
// and CD_ROM has the fixed block size as 2048 bytes, so...
//
VolDescriptorLba = 15;
//
// ((16*2048) / Media->BlockSize) - 1;
//
// Loop: handle one volume descriptor per time
//
while (TRUE) {
VolDescriptorLba += 1;
if (VolDescriptorLba > ParentBlockDev->LastBlock) {
//
// We are pointing past the end of the device so exit
//
break;
}
Status = FatReadBlock (
PrivateData,
ParentBlockDevNo,
VolDescriptorLba,
ParentBlockDev->BlockSize,
VolDescriptor
);
if (EFI_ERROR (Status)) {
break;
}
//
// Check for valid volume descriptor signature
//
if (VolDescriptor->Unknown.Type == CDVOL_TYPE_END ||
CompareMem (VolDescriptor->Unknown.Id, CDVOL_ID, sizeof (VolDescriptor->Unknown.Id)) != 0
) {
//
// end of Volume descriptor list
//
break;
}
//
// Read the Volume Space Size from Primary Volume Descriptor 81-88 byte
//
if (VolDescriptor->Unknown.Type == CDVOL_TYPE_CODED) {
VolSpaceSize = VolDescriptor->PrimaryVolume.VolSpaceSize[1];
}
//
// Is it an El Torito volume descriptor?
//
if (CompareMem (
VolDescriptor->BootRecordVolume.SystemId,
CDVOL_ELTORITO_ID,
sizeof (CDVOL_ELTORITO_ID) - 1
) != 0) {
continue;
}
//
// Read in the boot El Torito boot catalog
//
Lba = UNPACK_INT32 (VolDescriptor->BootRecordVolume.EltCatalog);
if (Lba > ParentBlockDev->LastBlock) {
continue;
}
Status = FatReadBlock (
PrivateData,
ParentBlockDevNo,
Lba,
ParentBlockDev->BlockSize,
Catalog
);
if (EFI_ERROR (Status)) {
continue;
}
//
// We don't care too much about the Catalog header's contents, but we do want
// to make sure it looks like a Catalog header
//
if (Catalog->Catalog.Indicator != ELTORITO_ID_CATALOG || Catalog->Catalog.Id55AA != 0xAA55) {
continue;
}
Check = 0;
CheckBuffer = (UINT16 *) Catalog;
for (Index = 0; Index < sizeof (ELTORITO_CATALOG) / sizeof (UINT16); Index += 1) {
Check += CheckBuffer[Index];
}
if ((Check & 0xFFFF) != 0) {
continue;
}
MaxIndex = ParentBlockDev->BlockSize / sizeof (ELTORITO_CATALOG);
for (Index = 1; Index < MaxIndex; Index += 1) {
//
// Next entry
//
Catalog += 1;
//
// Check this entry
//
if (Catalog->Boot.Indicator != ELTORITO_ID_SECTION_BOOTABLE || Catalog->Boot.Lba == 0) {
continue;
}
SubBlockSize = 512;
SectorCount = Catalog->Boot.SectorCount;
switch (Catalog->Boot.MediaType) {
case ELTORITO_NO_EMULATION:
SubBlockSize = ParentBlockDev->BlockSize;
SectorCount = Catalog->Boot.SectorCount;
break;
case ELTORITO_HARD_DISK:
break;
case ELTORITO_12_DISKETTE:
SectorCount = 0x50 * 0x02 * 0x0F;
break;
case ELTORITO_14_DISKETTE:
SectorCount = 0x50 * 0x02 * 0x12;
break;
case ELTORITO_28_DISKETTE:
SectorCount = 0x50 * 0x02 * 0x24;
break;
default:
SectorCount = 0;
SubBlockSize = ParentBlockDev->BlockSize;
break;
}
if (SectorCount < 2) {
SectorCount = (VolSpaceSize > ParentBlockDev->LastBlock + 1) ? (UINT32) (ParentBlockDev->LastBlock - Catalog->Boot.Lba + 1) : (UINT32) (VolSpaceSize - Catalog->Boot.Lba);
}
//
// Register this partition
//
if (PrivateData->BlockDeviceCount < PEI_FAT_MAX_BLOCK_DEVICE) {
Found = TRUE;
BlockDev = &(PrivateData->BlockDevice[PrivateData->BlockDeviceCount]);
BlockDev->BlockSize = SubBlockSize;
BlockDev->LastBlock = SectorCount - 1;
BlockDev->IoAlign = ParentBlockDev->IoAlign;
BlockDev->Logical = TRUE;
BlockDev->PartitionChecked = FALSE;
BlockDev->StartingPos = MultU64x32 (Catalog->Boot.Lba, ParentBlockDev->BlockSize);
BlockDev->ParentDevNo = ParentBlockDevNo;
PrivateData->BlockDeviceCount++;
}
}
}
ParentBlockDev->PartitionChecked = TRUE;
return Found;
}
/**
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
**/
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 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;
}
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