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-rw-r--r--src/Boot/Windows/BootDiskIo.cpp982
1 files changed, 491 insertions, 491 deletions
diff --git a/src/Boot/Windows/BootDiskIo.cpp b/src/Boot/Windows/BootDiskIo.cpp
index 31917a64..bf3fe9fc 100644
--- a/src/Boot/Windows/BootDiskIo.cpp
+++ b/src/Boot/Windows/BootDiskIo.cpp
@@ -1,491 +1,491 @@
-/*
- Derived from source code of TrueCrypt 7.1a, which is
- Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed
- by the TrueCrypt License 3.0.
-
- Modifications and additions to the original source code (contained in this file)
- and all other portions of this file are Copyright (c) 2013-2016 IDRIX
- and are governed by the Apache License 2.0 the full text of which is
- contained in the file License.txt included in VeraCrypt binary and source
- code distribution packages.
-*/
-
-#include "Bios.h"
-#include "BootConsoleIo.h"
-#include "BootConfig.h"
-#include "BootDebug.h"
-#include "BootDefs.h"
-#include "BootDiskIo.h"
-#include "BootStrings.h"
-
-
-byte SectorBuffer[TC_LB_SIZE];
-
-#ifdef TC_BOOT_DEBUG_ENABLED
-static bool SectorBufferInUse = false;
-
-void AcquireSectorBuffer ()
-{
- if (SectorBufferInUse)
- TC_THROW_FATAL_EXCEPTION;
-
- SectorBufferInUse = true;
-}
-
-
-void ReleaseSectorBuffer ()
-{
- SectorBufferInUse = false;
-}
-
-#endif
-
-
-bool IsLbaSupported (byte drive)
-{
- static byte CachedDrive = TC_INVALID_BIOS_DRIVE;
- static bool CachedStatus;
- uint16 result = 0;
-
- if (CachedDrive == drive)
- goto ret;
-
- __asm
- {
- mov bx, 0x55aa
- mov dl, drive
- mov ah, 0x41
- int 0x13
- jc err
- mov result, bx
- err:
- }
-
- CachedDrive = drive;
- CachedStatus = (result == 0xaa55);
-ret:
- return CachedStatus;
-}
-
-
-void PrintDiskError (BiosResult error, bool write, byte drive, const uint64 *sector, const ChsAddress *chs)
-{
- PrintEndl();
- Print (write ? "Write" : "Read"); Print (" error:");
- Print (error);
- Print (" Drive:");
- Print (drive ^ 0x80);
-
- if (sector)
- {
- Print (" Sector:");
- Print (*sector);
- }
-
- if (chs)
- {
- Print (" CHS:");
- Print (*chs);
- }
-
- PrintEndl();
- Beep();
-}
-
-
-void Print (const ChsAddress &chs)
-{
- Print (chs.Cylinder);
- PrintChar ('/');
- Print (chs.Head);
- PrintChar ('/');
- Print (chs.Sector);
-}
-
-
-void PrintSectorCountInMB (const uint64 &sectorCount)
-{
- Print (sectorCount >> (TC_LB_SIZE_BIT_SHIFT_DIVISOR + 2)); Print (" MB ");
-}
-
-
-BiosResult ReadWriteSectors (bool write, uint16 bufferSegment, uint16 bufferOffset, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
-{
- CheckStack();
-
- byte cylinderLow = (byte) chs.Cylinder;
- byte sector = chs.Sector;
- sector |= byte (chs.Cylinder >> 2) & 0xc0;
- byte function = write ? 0x03 : 0x02;
-
- BiosResult result;
- byte tryCount = TC_MAX_BIOS_DISK_IO_RETRIES;
-
- do
- {
- result = BiosResultSuccess;
-
- __asm
- {
- push es
- mov ax, bufferSegment
- mov es, ax
- mov bx, bufferOffset
- mov dl, drive
- mov ch, cylinderLow
- mov si, chs
- mov dh, [si].Head
- mov cl, sector
- mov al, sectorCount
- mov ah, function
- int 0x13
- jnc ok // If CF=0, ignore AH to prevent issues caused by potential bugs in BIOSes
- mov result, ah
- ok:
- pop es
- }
-
- if (result == BiosResultEccCorrected)
- result = BiosResultSuccess;
-
- // Some BIOSes report I/O errors prematurely in some cases
- } while (result != BiosResultSuccess && --tryCount != 0);
-
- if (!silent && result != BiosResultSuccess)
- PrintDiskError (result, write, drive, nullptr, &chs);
-
- return result;
-}
-
-
-BiosResult ReadWriteSectors (bool write, byte *buffer, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
-{
- uint16 codeSeg;
- __asm mov codeSeg, cs
- return ReadWriteSectors (write, codeSeg, (uint16) buffer, drive, chs, sectorCount, silent);
-}
-
-
-BiosResult ReadSectors (byte *buffer, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
-{
- return ReadWriteSectors (false, buffer, drive, chs, sectorCount, silent);
-}
-
-
-BiosResult WriteSectors (byte *buffer, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
-{
- return ReadWriteSectors (true, buffer, drive, chs, sectorCount, silent);
-}
-
-
-static BiosResult ReadWriteSectors (bool write, BiosLbaPacket &dapPacket, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
-{
- CheckStack();
-
- if (!IsLbaSupported (drive))
- {
- DriveGeometry geometry;
-
- BiosResult result = GetDriveGeometry (drive, geometry, silent);
- if (result != BiosResultSuccess)
- return result;
-
- ChsAddress chs;
- LbaToChs (geometry, sector, chs);
- return ReadWriteSectors (write, (uint16) (dapPacket.Buffer >> 16), (uint16) dapPacket.Buffer, drive, chs, sectorCount, silent);
- }
-
- dapPacket.Size = sizeof (dapPacket);
- dapPacket.Reserved = 0;
- dapPacket.SectorCount = sectorCount;
- dapPacket.Sector = sector;
-
- byte function = write ? 0x43 : 0x42;
-
- BiosResult result;
- byte tryCount = TC_MAX_BIOS_DISK_IO_RETRIES;
-
- do
- {
- result = BiosResultSuccess;
-
- __asm
- {
- mov bx, 0x55aa
- mov dl, drive
- mov si, [dapPacket]
- mov ah, function
- xor al, al
- int 0x13
- jnc ok // If CF=0, ignore AH to prevent issues caused by potential bugs in BIOSes
- mov result, ah
- ok:
- }
-
- if (result == BiosResultEccCorrected)
- result = BiosResultSuccess;
-
- // Some BIOSes report I/O errors prematurely in some cases
- } while (result != BiosResultSuccess && --tryCount != 0);
-
- if (!silent && result != BiosResultSuccess)
- PrintDiskError (result, write, drive, &sector);
-
- return result;
-}
-
-
-static BiosResult ReadWriteSectors (bool write, byte *buffer, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
-{
- BiosLbaPacket dapPacket;
- dapPacket.Buffer = (uint32) buffer;
- return ReadWriteSectors (write, dapPacket, drive, sector, sectorCount, silent);
-}
-
-
-BiosResult ReadWriteSectors (bool write, uint16 bufferSegment, uint16 bufferOffset, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
-{
- BiosLbaPacket dapPacket;
- dapPacket.Buffer = ((uint32) bufferSegment << 16) | bufferOffset;
- return ReadWriteSectors (write, dapPacket, drive, sector, sectorCount, silent);
-}
-
-BiosResult ReadSectors (uint16 bufferSegment, uint16 bufferOffset, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
-{
- return ReadWriteSectors (false, bufferSegment, bufferOffset, drive, sector, sectorCount, silent);
-}
-
-
-BiosResult ReadSectors (byte *buffer, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
-{
- BiosResult result;
- uint16 codeSeg;
- __asm mov codeSeg, cs
-
- result = ReadSectors (BootStarted ? codeSeg : TC_BOOT_LOADER_ALT_SEGMENT, (uint16) buffer, drive, sector, sectorCount, silent);
-
- // Alternative segment is used to prevent memory corruption caused by buggy BIOSes
- if (!BootStarted)
- CopyMemory (TC_BOOT_LOADER_ALT_SEGMENT, (uint16) buffer, buffer, sectorCount * TC_LB_SIZE);
-
- return result;
-}
-
-
-BiosResult WriteSectors (byte *buffer, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
-{
- return ReadWriteSectors (true, buffer, drive, sector, sectorCount, silent);
-}
-
-
-BiosResult GetDriveGeometry (byte drive, DriveGeometry &geometry, bool silent)
-{
- CheckStack();
-
- byte maxCylinderLow, maxHead, maxSector;
- BiosResult result;
- __asm
- {
- push es
- mov dl, drive
- mov ah, 0x08
- int 0x13
-
- mov result, ah
- mov maxCylinderLow, ch
- mov maxSector, cl
- mov maxHead, dh
- pop es
- }
-
- if (result == BiosResultSuccess)
- {
- geometry.Cylinders = (maxCylinderLow | (uint16 (maxSector & 0xc0) << 2)) + 1;
- geometry.Heads = maxHead + 1;
- geometry.Sectors = maxSector & ~0xc0;
- }
- else if (!silent)
- {
- Print ("Drive ");
- Print (drive ^ 0x80);
- Print (" not found: ");
- PrintErrorNoEndl ("");
- Print (result);
- PrintEndl();
- }
-
- return result;
-}
-
-
-void ChsToLba (const DriveGeometry &geometry, const ChsAddress &chs, uint64 &lba)
-{
- lba.HighPart = 0;
- lba.LowPart = (uint32 (chs.Cylinder) * geometry.Heads + chs.Head) * geometry.Sectors + chs.Sector - 1;
-}
-
-
-void LbaToChs (const DriveGeometry &geometry, const uint64 &lba, ChsAddress &chs)
-{
- chs.Sector = (byte) ((lba.LowPart % geometry.Sectors) + 1);
- uint32 ch = lba.LowPart / geometry.Sectors;
- chs.Head = (byte) (ch % geometry.Heads);
- chs.Cylinder = (uint16) (ch / geometry.Heads);
-}
-
-
-void PartitionEntryMBRToPartition (const PartitionEntryMBR &partEntry, Partition &partition)
-{
- partition.Active = partEntry.BootIndicator == 0x80;
- partition.EndSector.HighPart = 0;
- partition.EndSector.LowPart = partEntry.StartLBA + partEntry.SectorCountLBA - 1;
- partition.SectorCount.HighPart = 0;
- partition.SectorCount.LowPart = partEntry.SectorCountLBA;
- partition.StartSector.HighPart = 0;
- partition.StartSector.LowPart = partEntry.StartLBA;
- partition.Type = partEntry.Type;
-}
-
-
-BiosResult ReadWriteMBR (bool write, byte drive, bool silent)
-{
- uint64 mbrSector;
- mbrSector.HighPart = 0;
- mbrSector.LowPart = 0;
-
- if (write)
- return WriteSectors (SectorBuffer, drive, mbrSector, 1, silent);
-
- return ReadSectors (SectorBuffer, drive, mbrSector, 1, silent); // Uses alternative segment
-}
-
-
-BiosResult GetDrivePartitions (byte drive, Partition *partitionArray, size_t partitionArrayCapacity, size_t &partitionCount, bool activeOnly, Partition *findPartitionFollowingThis, bool silent)
-{
- Partition *followingPartition;
- Partition tmpPartition;
-
- if (findPartitionFollowingThis)
- {
- assert (partitionArrayCapacity == 1);
- partitionArrayCapacity = 0xff;
- followingPartition = partitionArray;
- partitionArray = &tmpPartition;
-
- followingPartition->Drive = TC_INVALID_BIOS_DRIVE;
- followingPartition->StartSector.LowPart = 0xFFFFffffUL;
- }
-
- AcquireSectorBuffer();
- BiosResult result = ReadWriteMBR (false, drive, silent);
- ReleaseSectorBuffer();
-
- partitionCount = 0;
-
- MBR *mbr = (MBR *) SectorBuffer;
- if (result != BiosResultSuccess || mbr->Signature != 0xaa55)
- return result;
-
- PartitionEntryMBR mbrPartitions[4];
- memcpy (mbrPartitions, mbr->Partitions, sizeof (mbrPartitions));
- size_t partitionArrayPos = 0, partitionNumber;
-
- for (partitionNumber = 0;
- partitionNumber < array_capacity (mbrPartitions) && partitionArrayPos < partitionArrayCapacity;
- ++partitionNumber)
- {
- const PartitionEntryMBR &partEntry = mbrPartitions[partitionNumber];
-
- if (partEntry.SectorCountLBA > 0)
- {
- Partition &partition = partitionArray[partitionArrayPos];
- PartitionEntryMBRToPartition (partEntry, partition);
-
- if (activeOnly && !partition.Active)
- continue;
-
- partition.Drive = drive;
- partition.Number = partitionArrayPos;
-
- if (partEntry.Type == 0x5 || partEntry.Type == 0xf) // Extended partition
- {
- if (IsLbaSupported (drive))
- {
- // Find all extended partitions
- uint64 firstExtStartLBA = partition.StartSector;
- uint64 extStartLBA = partition.StartSector;
- MBR *extMbr = (MBR *) SectorBuffer;
-
- while (partitionArrayPos < partitionArrayCapacity &&
- (result = ReadSectors ((byte *) extMbr, drive, extStartLBA, 1, silent)) == BiosResultSuccess
- && extMbr->Signature == 0xaa55)
- {
- if (extMbr->Partitions[0].SectorCountLBA > 0)
- {
- Partition &logPart = partitionArray[partitionArrayPos];
- PartitionEntryMBRToPartition (extMbr->Partitions[0], logPart);
- logPart.Drive = drive;
-
- logPart.Number = partitionArrayPos;
- logPart.Primary = false;
-
- logPart.StartSector.LowPart += extStartLBA.LowPart;
- logPart.EndSector.LowPart += extStartLBA.LowPart;
-
- if (findPartitionFollowingThis)
- {
- if (logPart.StartSector.LowPart > findPartitionFollowingThis->EndSector.LowPart
- && logPart.StartSector.LowPart < followingPartition->StartSector.LowPart)
- {
- *followingPartition = logPart;
- }
- }
- else
- ++partitionArrayPos;
- }
-
- // Secondary extended
- if (extMbr->Partitions[1].Type != 0x5 && extMbr->Partitions[1].Type == 0xf
- || extMbr->Partitions[1].SectorCountLBA == 0)
- break;
-
- extStartLBA.LowPart = extMbr->Partitions[1].StartLBA + firstExtStartLBA.LowPart;
- }
- }
- }
- else
- {
- partition.Primary = true;
-
- if (findPartitionFollowingThis)
- {
- if (partition.StartSector.LowPart > findPartitionFollowingThis->EndSector.LowPart
- && partition.StartSector.LowPart < followingPartition->StartSector.LowPart)
- {
- *followingPartition = partition;
- }
- }
- else
- ++partitionArrayPos;
- }
- }
- }
-
- partitionCount = partitionArrayPos;
- return result;
-}
-
-
-bool GetActivePartition (byte drive)
-{
- size_t partCount;
-
- if (GetDrivePartitions (drive, &ActivePartition, 1, partCount, true) != BiosResultSuccess || partCount < 1)
- {
- ActivePartition.Drive = TC_INVALID_BIOS_DRIVE;
- PrintError (TC_BOOT_STR_NO_BOOT_PARTITION);
- return false;
- }
-
- return true;
-}
+/*
+ Derived from source code of TrueCrypt 7.1a, which is
+ Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed
+ by the TrueCrypt License 3.0.
+
+ Modifications and additions to the original source code (contained in this file)
+ and all other portions of this file are Copyright (c) 2013-2016 IDRIX
+ and are governed by the Apache License 2.0 the full text of which is
+ contained in the file License.txt included in VeraCrypt binary and source
+ code distribution packages.
+*/
+
+#include "Bios.h"
+#include "BootConsoleIo.h"
+#include "BootConfig.h"
+#include "BootDebug.h"
+#include "BootDefs.h"
+#include "BootDiskIo.h"
+#include "BootStrings.h"
+
+
+byte SectorBuffer[TC_LB_SIZE];
+
+#ifdef TC_BOOT_DEBUG_ENABLED
+static bool SectorBufferInUse = false;
+
+void AcquireSectorBuffer ()
+{
+ if (SectorBufferInUse)
+ TC_THROW_FATAL_EXCEPTION;
+
+ SectorBufferInUse = true;
+}
+
+
+void ReleaseSectorBuffer ()
+{
+ SectorBufferInUse = false;
+}
+
+#endif
+
+
+bool IsLbaSupported (byte drive)
+{
+ static byte CachedDrive = TC_INVALID_BIOS_DRIVE;
+ static bool CachedStatus;
+ uint16 result = 0;
+
+ if (CachedDrive == drive)
+ goto ret;
+
+ __asm
+ {
+ mov bx, 0x55aa
+ mov dl, drive
+ mov ah, 0x41
+ int 0x13
+ jc err
+ mov result, bx
+ err:
+ }
+
+ CachedDrive = drive;
+ CachedStatus = (result == 0xaa55);
+ret:
+ return CachedStatus;
+}
+
+
+void PrintDiskError (BiosResult error, bool write, byte drive, const uint64 *sector, const ChsAddress *chs)
+{
+ PrintEndl();
+ Print (write ? "Write" : "Read"); Print (" error:");
+ Print (error);
+ Print (" Drive:");
+ Print (drive ^ 0x80);
+
+ if (sector)
+ {
+ Print (" Sector:");
+ Print (*sector);
+ }
+
+ if (chs)
+ {
+ Print (" CHS:");
+ Print (*chs);
+ }
+
+ PrintEndl();
+ Beep();
+}
+
+
+void Print (const ChsAddress &chs)
+{
+ Print (chs.Cylinder);
+ PrintChar ('/');
+ Print (chs.Head);
+ PrintChar ('/');
+ Print (chs.Sector);
+}
+
+
+void PrintSectorCountInMB (const uint64 &sectorCount)
+{
+ Print (sectorCount >> (TC_LB_SIZE_BIT_SHIFT_DIVISOR + 2)); Print (" MB ");
+}
+
+
+BiosResult ReadWriteSectors (bool write, uint16 bufferSegment, uint16 bufferOffset, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
+{
+ CheckStack();
+
+ byte cylinderLow = (byte) chs.Cylinder;
+ byte sector = chs.Sector;
+ sector |= byte (chs.Cylinder >> 2) & 0xc0;
+ byte function = write ? 0x03 : 0x02;
+
+ BiosResult result;
+ byte tryCount = TC_MAX_BIOS_DISK_IO_RETRIES;
+
+ do
+ {
+ result = BiosResultSuccess;
+
+ __asm
+ {
+ push es
+ mov ax, bufferSegment
+ mov es, ax
+ mov bx, bufferOffset
+ mov dl, drive
+ mov ch, cylinderLow
+ mov si, chs
+ mov dh, [si].Head
+ mov cl, sector
+ mov al, sectorCount
+ mov ah, function
+ int 0x13
+ jnc ok // If CF=0, ignore AH to prevent issues caused by potential bugs in BIOSes
+ mov result, ah
+ ok:
+ pop es
+ }
+
+ if (result == BiosResultEccCorrected)
+ result = BiosResultSuccess;
+
+ // Some BIOSes report I/O errors prematurely in some cases
+ } while (result != BiosResultSuccess && --tryCount != 0);
+
+ if (!silent && result != BiosResultSuccess)
+ PrintDiskError (result, write, drive, nullptr, &chs);
+
+ return result;
+}
+
+
+BiosResult ReadWriteSectors (bool write, byte *buffer, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
+{
+ uint16 codeSeg;
+ __asm mov codeSeg, cs
+ return ReadWriteSectors (write, codeSeg, (uint16) buffer, drive, chs, sectorCount, silent);
+}
+
+
+BiosResult ReadSectors (byte *buffer, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
+{
+ return ReadWriteSectors (false, buffer, drive, chs, sectorCount, silent);
+}
+
+
+BiosResult WriteSectors (byte *buffer, byte drive, const ChsAddress &chs, byte sectorCount, bool silent)
+{
+ return ReadWriteSectors (true, buffer, drive, chs, sectorCount, silent);
+}
+
+
+static BiosResult ReadWriteSectors (bool write, BiosLbaPacket &dapPacket, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
+{
+ CheckStack();
+
+ if (!IsLbaSupported (drive))
+ {
+ DriveGeometry geometry;
+
+ BiosResult result = GetDriveGeometry (drive, geometry, silent);
+ if (result != BiosResultSuccess)
+ return result;
+
+ ChsAddress chs;
+ LbaToChs (geometry, sector, chs);
+ return ReadWriteSectors (write, (uint16) (dapPacket.Buffer >> 16), (uint16) dapPacket.Buffer, drive, chs, sectorCount, silent);
+ }
+
+ dapPacket.Size = sizeof (dapPacket);
+ dapPacket.Reserved = 0;
+ dapPacket.SectorCount = sectorCount;
+ dapPacket.Sector = sector;
+
+ byte function = write ? 0x43 : 0x42;
+
+ BiosResult result;
+ byte tryCount = TC_MAX_BIOS_DISK_IO_RETRIES;
+
+ do
+ {
+ result = BiosResultSuccess;
+
+ __asm
+ {
+ mov bx, 0x55aa
+ mov dl, drive
+ mov si, [dapPacket]
+ mov ah, function
+ xor al, al
+ int 0x13
+ jnc ok // If CF=0, ignore AH to prevent issues caused by potential bugs in BIOSes
+ mov result, ah
+ ok:
+ }
+
+ if (result == BiosResultEccCorrected)
+ result = BiosResultSuccess;
+
+ // Some BIOSes report I/O errors prematurely in some cases
+ } while (result != BiosResultSuccess && --tryCount != 0);
+
+ if (!silent && result != BiosResultSuccess)
+ PrintDiskError (result, write, drive, &sector);
+
+ return result;
+}
+
+
+static BiosResult ReadWriteSectors (bool write, byte *buffer, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
+{
+ BiosLbaPacket dapPacket;
+ dapPacket.Buffer = (uint32) buffer;
+ return ReadWriteSectors (write, dapPacket, drive, sector, sectorCount, silent);
+}
+
+
+BiosResult ReadWriteSectors (bool write, uint16 bufferSegment, uint16 bufferOffset, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
+{
+ BiosLbaPacket dapPacket;
+ dapPacket.Buffer = ((uint32) bufferSegment << 16) | bufferOffset;
+ return ReadWriteSectors (write, dapPacket, drive, sector, sectorCount, silent);
+}
+
+BiosResult ReadSectors (uint16 bufferSegment, uint16 bufferOffset, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
+{
+ return ReadWriteSectors (false, bufferSegment, bufferOffset, drive, sector, sectorCount, silent);
+}
+
+
+BiosResult ReadSectors (byte *buffer, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
+{
+ BiosResult result;
+ uint16 codeSeg;
+ __asm mov codeSeg, cs
+
+ result = ReadSectors (BootStarted ? codeSeg : TC_BOOT_LOADER_ALT_SEGMENT, (uint16) buffer, drive, sector, sectorCount, silent);
+
+ // Alternative segment is used to prevent memory corruption caused by buggy BIOSes
+ if (!BootStarted)
+ CopyMemory (TC_BOOT_LOADER_ALT_SEGMENT, (uint16) buffer, buffer, sectorCount * TC_LB_SIZE);
+
+ return result;
+}
+
+
+BiosResult WriteSectors (byte *buffer, byte drive, const uint64 &sector, uint16 sectorCount, bool silent)
+{
+ return ReadWriteSectors (true, buffer, drive, sector, sectorCount, silent);
+}
+
+
+BiosResult GetDriveGeometry (byte drive, DriveGeometry &geometry, bool silent)
+{
+ CheckStack();
+
+ byte maxCylinderLow, maxHead, maxSector;
+ BiosResult result;
+ __asm
+ {
+ push es
+ mov dl, drive
+ mov ah, 0x08
+ int 0x13
+
+ mov result, ah
+ mov maxCylinderLow, ch
+ mov maxSector, cl
+ mov maxHead, dh
+ pop es
+ }
+
+ if (result == BiosResultSuccess)
+ {
+ geometry.Cylinders = (maxCylinderLow | (uint16 (maxSector & 0xc0) << 2)) + 1;
+ geometry.Heads = maxHead + 1;
+ geometry.Sectors = maxSector & ~0xc0;
+ }
+ else if (!silent)
+ {
+ Print ("Drive ");
+ Print (drive ^ 0x80);
+ Print (" not found: ");
+ PrintErrorNoEndl ("");
+ Print (result);
+ PrintEndl();
+ }
+
+ return result;
+}
+
+
+void ChsToLba (const DriveGeometry &geometry, const ChsAddress &chs, uint64 &lba)
+{
+ lba.HighPart = 0;
+ lba.LowPart = (uint32 (chs.Cylinder) * geometry.Heads + chs.Head) * geometry.Sectors + chs.Sector - 1;
+}
+
+
+void LbaToChs (const DriveGeometry &geometry, const uint64 &lba, ChsAddress &chs)
+{
+ chs.Sector = (byte) ((lba.LowPart % geometry.Sectors) + 1);
+ uint32 ch = lba.LowPart / geometry.Sectors;
+ chs.Head = (byte) (ch % geometry.Heads);
+ chs.Cylinder = (uint16) (ch / geometry.Heads);
+}
+
+
+void PartitionEntryMBRToPartition (const PartitionEntryMBR &partEntry, Partition &partition)
+{
+ partition.Active = partEntry.BootIndicator == 0x80;
+ partition.EndSector.HighPart = 0;
+ partition.EndSector.LowPart = partEntry.StartLBA + partEntry.SectorCountLBA - 1;
+ partition.SectorCount.HighPart = 0;
+ partition.SectorCount.LowPart = partEntry.SectorCountLBA;
+ partition.StartSector.HighPart = 0;
+ partition.StartSector.LowPart = partEntry.StartLBA;
+ partition.Type = partEntry.Type;
+}
+
+
+BiosResult ReadWriteMBR (bool write, byte drive, bool silent)
+{
+ uint64 mbrSector;
+ mbrSector.HighPart = 0;
+ mbrSector.LowPart = 0;
+
+ if (write)
+ return WriteSectors (SectorBuffer, drive, mbrSector, 1, silent);
+
+ return ReadSectors (SectorBuffer, drive, mbrSector, 1, silent); // Uses alternative segment
+}
+
+
+BiosResult GetDrivePartitions (byte drive, Partition *partitionArray, size_t partitionArrayCapacity, size_t &partitionCount, bool activeOnly, Partition *findPartitionFollowingThis, bool silent)
+{
+ Partition *followingPartition;
+ Partition tmpPartition;
+
+ if (findPartitionFollowingThis)
+ {
+ assert (partitionArrayCapacity == 1);
+ partitionArrayCapacity = 0xff;
+ followingPartition = partitionArray;
+ partitionArray = &tmpPartition;
+
+ followingPartition->Drive = TC_INVALID_BIOS_DRIVE;
+ followingPartition->StartSector.LowPart = 0xFFFFffffUL;
+ }
+
+ AcquireSectorBuffer();
+ BiosResult result = ReadWriteMBR (false, drive, silent);
+ ReleaseSectorBuffer();
+
+ partitionCount = 0;
+
+ MBR *mbr = (MBR *) SectorBuffer;
+ if (result != BiosResultSuccess || mbr->Signature != 0xaa55)
+ return result;
+
+ PartitionEntryMBR mbrPartitions[4];
+ memcpy (mbrPartitions, mbr->Partitions, sizeof (mbrPartitions));
+ size_t partitionArrayPos = 0, partitionNumber;
+
+ for (partitionNumber = 0;
+ partitionNumber < array_capacity (mbrPartitions) && partitionArrayPos < partitionArrayCapacity;
+ ++partitionNumber)
+ {
+ const PartitionEntryMBR &partEntry = mbrPartitions[partitionNumber];
+
+ if (partEntry.SectorCountLBA > 0)
+ {
+ Partition &partition = partitionArray[partitionArrayPos];
+ PartitionEntryMBRToPartition (partEntry, partition);
+
+ if (activeOnly && !partition.Active)
+ continue;
+
+ partition.Drive = drive;
+ partition.Number = partitionArrayPos;
+
+ if (partEntry.Type == 0x5 || partEntry.Type == 0xf) // Extended partition
+ {
+ if (IsLbaSupported (drive))
+ {
+ // Find all extended partitions
+ uint64 firstExtStartLBA = partition.StartSector;
+ uint64 extStartLBA = partition.StartSector;
+ MBR *extMbr = (MBR *) SectorBuffer;
+
+ while (partitionArrayPos < partitionArrayCapacity &&
+ (result = ReadSectors ((byte *) extMbr, drive, extStartLBA, 1, silent)) == BiosResultSuccess
+ && extMbr->Signature == 0xaa55)
+ {
+ if (extMbr->Partitions[0].SectorCountLBA > 0)
+ {
+ Partition &logPart = partitionArray[partitionArrayPos];
+ PartitionEntryMBRToPartition (extMbr->Partitions[0], logPart);
+ logPart.Drive = drive;
+
+ logPart.Number = partitionArrayPos;
+ logPart.Primary = false;
+
+ logPart.StartSector.LowPart += extStartLBA.LowPart;
+ logPart.EndSector.LowPart += extStartLBA.LowPart;
+
+ if (findPartitionFollowingThis)
+ {
+ if (logPart.StartSector.LowPart > findPartitionFollowingThis->EndSector.LowPart
+ && logPart.StartSector.LowPart < followingPartition->StartSector.LowPart)
+ {
+ *followingPartition = logPart;
+ }
+ }
+ else
+ ++partitionArrayPos;
+ }
+
+ // Secondary extended
+ if (extMbr->Partitions[1].Type != 0x5 && extMbr->Partitions[1].Type == 0xf
+ || extMbr->Partitions[1].SectorCountLBA == 0)
+ break;
+
+ extStartLBA.LowPart = extMbr->Partitions[1].StartLBA + firstExtStartLBA.LowPart;
+ }
+ }
+ }
+ else
+ {
+ partition.Primary = true;
+
+ if (findPartitionFollowingThis)
+ {
+ if (partition.StartSector.LowPart > findPartitionFollowingThis->EndSector.LowPart
+ && partition.StartSector.LowPart < followingPartition->StartSector.LowPart)
+ {
+ *followingPartition = partition;
+ }
+ }
+ else
+ ++partitionArrayPos;
+ }
+ }
+ }
+
+ partitionCount = partitionArrayPos;
+ return result;
+}
+
+
+bool GetActivePartition (byte drive)
+{
+ size_t partCount;
+
+ if (GetDrivePartitions (drive, &ActivePartition, 1, partCount, true) != BiosResultSuccess || partCount < 1)
+ {
+ ActivePartition.Drive = TC_INVALID_BIOS_DRIVE;
+ PrintError (TC_BOOT_STR_NO_BOOT_PARTITION);
+ return false;
+ }
+
+ return true;
+}