[reactos] 01/01: [FREELDR] Add disk access handlers for UEFI (#5219)

[Justin Miller]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=1fd9d11f160c10e70311b…

commit 1fd9d11f160c10e70311b4176d0fad950b6cfe54
Author:     Justin Miller <justinmiller100(a)gmail.com>
AuthorDate: Sun Apr 30 05:57:10 2023 -0700
Commit:     GitHub <noreply(a)github.com>
CommitDate: Sun Apr 30 14:57:10 2023 +0200

    [FREELDR] Add disk access handlers for UEFI (#5219)
    
    CORE-11953
---
 boot/freeldr/freeldr/arch/uefi/stubs.c    |  34 --
 boot/freeldr/freeldr/arch/uefi/uefidisk.c | 596 ++++++++++++++++++++++++++++++
 boot/freeldr/freeldr/uefi.cmake           |   7 +-
 3 files changed, 600 insertions(+), 37 deletions(-)

diff --git a/boot/freeldr/freeldr/arch/uefi/stubs.c
b/boot/freeldr/freeldr/arch/uefi/stubs.c
index 75f7ee0fc8b..28f11b7795b 100644
--- a/boot/freeldr/freeldr/arch/uefi/stubs.c
+++ b/boot/freeldr/freeldr/arch/uefi/stubs.c
@@ -48,40 +48,6 @@ UefiGetExtendedBIOSData(PULONG ExtendedBIOSDataArea,
 
 }
 
-UCHAR
-UefiGetFloppyCount(VOID)
-{
-    return 0;
-}
-
-BOOLEAN
-UefiDiskReadLogicalSectors(IN UCHAR DriveNumber,
-                           IN ULONGLONG SectorNumber,
-                           IN ULONG SectorCount,
-                           OUT PVOID Buffer)
-{
-    return 0;
-}
-
-BOOLEAN
-UefiDiskGetDriveGeometry(UCHAR DriveNumber,
-                         PGEOMETRY Geometry)
-{
-    return 0;
-}
-
-ULONG
-UefiDiskGetCacheableBlockCount(UCHAR DriveNumber)
-{
-    return 0;
-}
-
-BOOLEAN
-UefiInitializeBootDevices(VOID)
-{
-    return 0;
-}
-
 PCONFIGURATION_COMPONENT_DATA
 UefiHwDetect(VOID)
 {
diff --git a/boot/freeldr/freeldr/arch/uefi/uefidisk.c
b/boot/freeldr/freeldr/arch/uefi/uefidisk.c
new file mode 100644
index 00000000000..772cdece7ce
--- /dev/null
+++ b/boot/freeldr/freeldr/arch/uefi/uefidisk.c
@@ -0,0 +1,596 @@
+/*
+ * PROJECT:     FreeLoader UEFI Support
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     Disk Access Functions
+ * COPYRIGHT:   Copyright 2022 Justin Miller <justinmiller100(a)gmail.com>
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <uefildr.h>
+
+#include <debug.h>
+DBG_DEFAULT_CHANNEL(WARNING);
+
+#define TAG_HW_RESOURCE_LIST    'lRwH'
+#define TAG_HW_DISK_CONTEXT     'cDwH'
+#define FIRST_BIOS_DISK 0x80
+#define FIRST_PARTITION 1
+
+typedef struct tagDISKCONTEXT
+{
+    UCHAR DriveNumber;
+    ULONG SectorSize;
+    ULONGLONG SectorOffset;
+    ULONGLONG SectorCount;
+    ULONGLONG SectorNumber;
+} DISKCONTEXT;
+
+typedef struct _INTERNAL_UEFI_DISK
+{
+    UCHAR ArcDriveNumber;
+    UCHAR NumOfPartitions;
+    UCHAR UefiRootNumber;
+    BOOLEAN IsThisTheBootDrive;
+} INTERNAL_UEFI_DISK, *PINTERNAL_UEFI_DISK;
+
+/* GLOBALS *******************************************************************/
+
+extern EFI_SYSTEM_TABLE* GlobalSystemTable;
+extern EFI_HANDLE GlobalImageHandle;
+extern EFI_HANDLE PublicBootHandle; /* Freeldr itself */
+
+/* Made to match BIOS */
+PVOID DiskReadBuffer;
+UCHAR PcBiosDiskCount;
+
+UCHAR FrldrBootDrive;
+ULONG FrldrBootPartition;
+SIZE_T DiskReadBufferSize;
+PVOID Buffer;
+
+static const CHAR Hex[] = "0123456789abcdef";
+static CHAR PcDiskIdentifier[32][20];
+
+/* UEFI-specific */
+static ULONG UefiBootRootIdentifier;
+static ULONG OffsetToBoot;
+static ULONG PublicBootArcDisk;
+static INTERNAL_UEFI_DISK* InternalUefiDisk = NULL;
+static EFI_GUID bioGuid = BLOCK_IO_PROTOCOL;
+static EFI_BLOCK_IO* bio;
+static EFI_HANDLE* handles = NULL;
+
+/* FUNCTIONS *****************************************************************/
+
+PCHAR
+GetHarddiskIdentifier(UCHAR DriveNumber)
+{
+    TRACE("GetHarddiskIdentifier: DriveNumber: %d\n", DriveNumber);
+    return PcDiskIdentifier[DriveNumber - FIRST_BIOS_DISK];
+}
+
+static LONG lReportError = 0; // >= 0: display errors; < 0: hide errors.
+
+LONG
+DiskReportError(BOOLEAN bShowError)
+{
+    /* Set the reference count */
+    if (bShowError) ++lReportError;
+    else            --lReportError;
+    return lReportError;
+}
+
+static
+BOOLEAN
+UefiGetBootPartitionEntry(
+    IN UCHAR DriveNumber,
+    OUT PPARTITION_TABLE_ENTRY PartitionTableEntry,
+    OUT PULONG BootPartition)
+{
+    ULONG PartitionNum;
+
+    TRACE("UefiGetBootPartitionEntry: DriveNumber: %d\n", DriveNumber -
FIRST_BIOS_DISK);
+    /* UefiBootRoot is the offset into the array of handles where the raw disk of the
boot drive is.
+     * Partitions start with 1 in ARC, but UEFI root drive identitfier is also first
partition. */
+    PartitionNum = (OffsetToBoot - UefiBootRootIdentifier);
+    if (PartitionNum == 0)
+    {
+        TRACE("Boot PartitionNumber is 0\n");
+        /* The OffsetToBoot is equal to the RootIdentifier */
+        PartitionNum = 1;
+    }
+
+    *BootPartition = PartitionNum;
+    TRACE("UefiGetBootPartitionEntry: Boot Partition is: %d\n", PartitionNum);
+    return TRUE;
+}
+
+static
+ARC_STATUS
+UefiDiskClose(ULONG FileId)
+{
+    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
+    FrLdrTempFree(Context, TAG_HW_DISK_CONTEXT);
+    return ESUCCESS;
+}
+
+static
+ARC_STATUS
+UefiDiskGetFileInformation(ULONG FileId, FILEINFORMATION *Information)
+{
+    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
+    RtlZeroMemory(Information, sizeof(*Information));
+
+    /*
+     * The ARC specification mentions that for partitions, StartingAddress and
+     * EndingAddress are the start and end positions of the partition in terms
+     * of byte offsets from the start of the disk.
+     * CurrentAddress is the current offset into (i.e. relative to) the partition.
+     */
+    Information->StartingAddress.QuadPart = Context->SectorOffset *
Context->SectorSize;
+    Information->EndingAddress.QuadPart   = (Context->SectorOffset +
Context->SectorCount) * Context->SectorSize;
+    Information->CurrentAddress.QuadPart  = Context->SectorNumber *
Context->SectorSize;
+
+    return ESUCCESS;
+}
+
+static
+ARC_STATUS
+UefiDiskOpen(CHAR *Path, OPENMODE OpenMode, ULONG *FileId)
+{
+    DISKCONTEXT* Context;
+    UCHAR DriveNumber;
+    ULONG DrivePartition, SectorSize;
+    ULONGLONG SectorOffset = 0;
+    ULONGLONG SectorCount = 0;
+    ULONG UefiDriveNumber = 0;
+    PARTITION_TABLE_ENTRY PartitionTableEntry;
+
+    TRACE("UefiDiskOpen: File ID: %d, Path: %s\n", FileId, Path);
+
+    if (DiskReadBufferSize == 0)
+    {
+        ERR("DiskOpen(): DiskReadBufferSize is 0, something is wrong.\n");
+        ASSERT(FALSE);
+        return ENOMEM;
+    }
+
+    if (!DissectArcPath(Path, NULL, &DriveNumber, &DrivePartition))
+        return EINVAL;
+
+    TRACE("Opening disk: DriveNumber: %d, DrivePartition: %d\n", DriveNumber,
DrivePartition);
+    UefiDriveNumber = DriveNumber - FIRST_BIOS_DISK;
+    GlobalSystemTable->BootServices->HandleProtocol(handles[UefiDriveNumber],
&bioGuid, (void**)&bio);
+    SectorSize = bio->Media->BlockSize;
+
+    if (DrivePartition != 0xff && DrivePartition != 0)
+    {
+        if (!DiskGetPartitionEntry(DriveNumber, DrivePartition,
&PartitionTableEntry))
+            return EINVAL;
+
+        SectorOffset = PartitionTableEntry.SectorCountBeforePartition;
+        SectorCount = PartitionTableEntry.PartitionSectorCount;
+    }
+    else
+    {
+        GEOMETRY Geometry;
+        if (!MachDiskGetDriveGeometry(DriveNumber, &Geometry))
+            return EINVAL;
+
+        if (SectorSize != Geometry.BytesPerSector)
+        {
+            ERR("SectorSize (%lu) != Geometry.BytesPerSector (%lu), expect
problems!\n",
+                SectorSize, Geometry.BytesPerSector);
+        }
+
+        SectorOffset = 0;
+        SectorCount = (ULONGLONG)Geometry.Cylinders * Geometry.Heads * Geometry.Sectors;
+    }
+
+    Context = FrLdrTempAlloc(sizeof(DISKCONTEXT), TAG_HW_DISK_CONTEXT);
+    if (!Context)
+        return ENOMEM;
+
+    Context->DriveNumber = DriveNumber;
+    Context->SectorSize = SectorSize;
+    Context->SectorOffset = SectorOffset;
+    Context->SectorCount = SectorCount;
+    Context->SectorNumber = 0;
+    FsSetDeviceSpecific(*FileId, Context);
+    return ESUCCESS;
+}
+
+static
+ARC_STATUS
+UefiDiskRead(ULONG FileId, VOID *Buffer, ULONG N, ULONG *Count)
+{
+    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
+    UCHAR* Ptr = (UCHAR*)Buffer;
+    ULONG Length, TotalSectors, MaxSectors, ReadSectors;
+    ULONGLONG SectorOffset;
+    BOOLEAN ret;
+
+    ASSERT(DiskReadBufferSize > 0);
+
+    TotalSectors = (N + Context->SectorSize - 1) / Context->SectorSize;
+    MaxSectors   = DiskReadBufferSize / Context->SectorSize;
+    SectorOffset = Context->SectorOffset + Context->SectorNumber;
+
+    // If MaxSectors is 0, this will lead to infinite loop.
+    // In release builds assertions are disabled, however we also have sanity checks in
DiskOpen()
+    ASSERT(MaxSectors > 0);
+
+    ret = TRUE;
+
+    while (TotalSectors)
+    {
+        ReadSectors = min(TotalSectors, MaxSectors);
+
+        ret = MachDiskReadLogicalSectors(Context->DriveNumber,
+                                         SectorOffset,
+                                         ReadSectors,
+                                         DiskReadBuffer);
+        if (!ret)
+            break;
+
+        Length = ReadSectors * Context->SectorSize;
+        Length = min(Length, N);
+
+        RtlCopyMemory(Ptr, DiskReadBuffer, Length);
+
+        Ptr += Length;
+        N -= Length;
+        SectorOffset += ReadSectors;
+        TotalSectors -= ReadSectors;
+    }
+
+    *Count = (ULONG)((ULONG_PTR)Ptr - (ULONG_PTR)Buffer);
+    Context->SectorNumber = SectorOffset - Context->SectorOffset;
+
+    return (ret ? ESUCCESS : EIO);
+}
+
+static
+ARC_STATUS
+UefiDiskSeek(ULONG FileId, LARGE_INTEGER *Position, SEEKMODE SeekMode)
+{
+    DISKCONTEXT* Context = FsGetDeviceSpecific(FileId);
+    LARGE_INTEGER NewPosition = *Position;
+
+    switch (SeekMode)
+    {
+        case SeekAbsolute:
+            break;
+        case SeekRelative:
+            NewPosition.QuadPart += (Context->SectorNumber * Context->SectorSize);
+            break;
+        default:
+            ASSERT(FALSE);
+            return EINVAL;
+    }
+
+    if (NewPosition.QuadPart & (Context->SectorSize - 1))
+        return EINVAL;
+
+    /* Convert in number of sectors */
+    NewPosition.QuadPart /= Context->SectorSize;
+
+    /* HACK: CDROMs may have a SectorCount of 0 */
+    if (Context->SectorCount != 0 && NewPosition.QuadPart >=
Context->SectorCount)
+        return EINVAL;
+
+    Context->SectorNumber = NewPosition.QuadPart;
+    return ESUCCESS;
+}
+
+static const DEVVTBL UefiDiskVtbl =
+{
+    UefiDiskClose,
+    UefiDiskGetFileInformation,
+    UefiDiskOpen,
+    UefiDiskRead,
+    UefiDiskSeek,
+};
+
+static
+VOID
+GetHarddiskInformation(UCHAR DriveNumber)
+{
+    PMASTER_BOOT_RECORD Mbr;
+    PULONG Buffer;
+    ULONG i;
+    ULONG Checksum;
+    ULONG Signature;
+    BOOLEAN ValidPartitionTable;
+    CHAR ArcName[MAX_PATH];
+    PARTITION_TABLE_ENTRY PartitionTableEntry;
+    PCHAR Identifier = PcDiskIdentifier[DriveNumber - FIRST_BIOS_DISK];
+
+    /* Detect disk partition type */
+    DiskDetectPartitionType(DriveNumber);
+
+    /* Read the MBR */
+    if (!MachDiskReadLogicalSectors(DriveNumber, 0ULL, 1, DiskReadBuffer))
+    {
+        ERR("Reading MBR failed\n");
+        /* We failed, use a default identifier */
+        sprintf(Identifier, "BIOSDISK%d", DriveNumber - FIRST_BIOS_DISK);
+        return;
+    }
+
+    Buffer = (ULONG*)DiskReadBuffer;
+    Mbr = (PMASTER_BOOT_RECORD)DiskReadBuffer;
+
+    Signature = Mbr->Signature;
+    TRACE("Signature: %x\n", Signature);
+
+    /* Calculate the MBR checksum */
+    Checksum = 0;
+    for (i = 0; i < 512 / sizeof(ULONG); i++)
+    {
+        Checksum += Buffer[i];
+    }
+    Checksum = ~Checksum + 1;
+    TRACE("Checksum: %x\n", Checksum);
+
+    ValidPartitionTable = (Mbr->MasterBootRecordMagic == 0xAA55);
+
+    /* Fill out the ARC disk block */
+    sprintf(ArcName, "multi(0)disk(0)rdisk(%u)", DriveNumber -
FIRST_BIOS_DISK);
+    AddReactOSArcDiskInfo(ArcName, Signature, Checksum, ValidPartitionTable);
+
+    sprintf(ArcName, "multi(0)disk(0)rdisk(%u)partition(0)", DriveNumber -
FIRST_BIOS_DISK);
+    FsRegisterDevice(ArcName, &UefiDiskVtbl);
+
+    /* Add partitions */
+    i = FIRST_PARTITION;
+    DiskReportError(FALSE);
+    while (DiskGetPartitionEntry(DriveNumber, i, &PartitionTableEntry))
+    {
+        if (PartitionTableEntry.SystemIndicator != PARTITION_ENTRY_UNUSED)
+        {
+            sprintf(ArcName, "multi(0)disk(0)rdisk(%u)partition(%lu)",
DriveNumber - FIRST_BIOS_DISK, i);
+            FsRegisterDevice(ArcName, &UefiDiskVtbl);
+        }
+        i++;
+    }
+    DiskReportError(TRUE);
+
+    InternalUefiDisk[DriveNumber].NumOfPartitions = i;
+    /* Convert checksum and signature to identifier string */
+    Identifier[0] = Hex[(Checksum >> 28) & 0x0F];
+    Identifier[1] = Hex[(Checksum >> 24) & 0x0F];
+    Identifier[2] = Hex[(Checksum >> 20) & 0x0F];
+    Identifier[3] = Hex[(Checksum >> 16) & 0x0F];
+    Identifier[4] = Hex[(Checksum >> 12) & 0x0F];
+    Identifier[5] = Hex[(Checksum >> 8) & 0x0F];
+    Identifier[6] = Hex[(Checksum >> 4) & 0x0F];
+    Identifier[7] = Hex[Checksum & 0x0F];
+    Identifier[8] = '-';
+    Identifier[9] = Hex[(Signature >> 28) & 0x0F];
+    Identifier[10] = Hex[(Signature >> 24) & 0x0F];
+    Identifier[11] = Hex[(Signature >> 20) & 0x0F];
+    Identifier[12] = Hex[(Signature >> 16) & 0x0F];
+    Identifier[13] = Hex[(Signature >> 12) & 0x0F];
+    Identifier[14] = Hex[(Signature >> 8) & 0x0F];
+    Identifier[15] = Hex[(Signature >> 4) & 0x0F];
+    Identifier[16] = Hex[Signature & 0x0F];
+    Identifier[17] = '-';
+    Identifier[18] = (ValidPartitionTable ? 'A' : 'X');
+    Identifier[19] = 0;
+    TRACE("Identifier: %s\n", Identifier);
+}
+
+static
+VOID
+UefiSetupBlockDevices(VOID)
+{
+    ULONG BlockDeviceIndex;
+    ULONG SystemHandleCount;
+    EFI_STATUS Status;
+    ULONG i;
+
+    UINTN handle_size = 0;
+    PcBiosDiskCount = 0;
+    UefiBootRootIdentifier = 0;
+
+    /* 1) Setup a list of boothandles by using the LocateHandle protocol */
+    Status = GlobalSystemTable->BootServices->LocateHandle(ByProtocol,
&bioGuid, NULL, &handle_size, handles);
+    handles = MmAllocateMemoryWithType(handle_size, LoaderFirmwareTemporary);
+    Status = GlobalSystemTable->BootServices->LocateHandle(ByProtocol,
&bioGuid, NULL, &handle_size, handles);
+    SystemHandleCount = handle_size / sizeof(EFI_HANDLE);
+    InternalUefiDisk = MmAllocateMemoryWithType(sizeof(INTERNAL_UEFI_DISK) *
SystemHandleCount, LoaderFirmwareTemporary);
+
+    BlockDeviceIndex = 0;
+    /* 2) Parse the handle list */
+    for (i = 0; i < SystemHandleCount; ++i)
+    {
+        Status = GlobalSystemTable->BootServices->HandleProtocol(handles[i],
&bioGuid, (void**)&bio);
+        if (handles[i] == PublicBootHandle)
+        {
+            OffsetToBoot = i; /* Drive offset in the handles list */
+        }
+
+        if (EFI_ERROR(Status) || 
+            bio == NULL ||
+            bio->Media->BlockSize == 0 ||
+            bio->Media->BlockSize > 2048)
+        {
+            TRACE("UefiSetupBlockDevices: UEFI has found a block device that failed,
skipping\n");
+            continue;
+        }
+        if (bio->Media->LogicalPartition == FALSE)
+        {
+            TRACE("Found root of a HDD\n");
+            PcBiosDiskCount++;
+            InternalUefiDisk[BlockDeviceIndex].ArcDriveNumber = BlockDeviceIndex;
+            InternalUefiDisk[BlockDeviceIndex].UefiRootNumber = i;
+            GetHarddiskInformation(BlockDeviceIndex + FIRST_BIOS_DISK);
+            BlockDeviceIndex++;
+        }
+        else if (handles[i] == PublicBootHandle)
+        {
+            ULONG increment = 0;
+            ULONG i;
+
+            /* 3) Grab the offset into the array of handles and decrement per volume
(valid partition) */
+            for (increment = OffsetToBoot; increment > 0; increment--)
+            {
+                GlobalSystemTable->BootServices->HandleProtocol(handles[increment],
&bioGuid, (void**)&bio);
+                if (bio->Media->LogicalPartition == FALSE)
+                {
+                    TRACE("Found root at increment %u\n", increment);
+                    UefiBootRootIdentifier = increment;
+
+                    for (i = 0; i <= PcBiosDiskCount; ++i)
+                    {
+                        /* Now only of the root drive number is equal to this drive we
found above */
+                        if (InternalUefiDisk[i].UefiRootNumber ==
UefiBootRootIdentifier)
+                        {
+                            InternalUefiDisk[i].IsThisTheBootDrive == TRUE;
+                            PublicBootArcDisk = i;
+                            TRACE("Found Boot drive\n");
+                        }
+                    }
+
+                    break;
+                }
+            }
+        }
+    }
+}
+
+static
+BOOLEAN
+UefiSetBootpath(VOID)
+{
+   TRACE("UefiSetBootpath: Setting up boot path\n");
+   GlobalSystemTable->BootServices->HandleProtocol(handles[UefiBootRootIdentifier],
&bioGuid, (void**)&bio);
+   FrldrBootDrive = (FIRST_BIOS_DISK + PublicBootArcDisk);
+   if (bio->Media->RemovableMedia == TRUE && bio->Media->BlockSize ==
2048)
+   {
+        /* Boot Partition 0xFF is the magic value that indicates booting from CD-ROM (see
isoboot.S) */
+        FrldrBootPartition == 0xFF;
+        RtlStringCbPrintfA(FrLdrBootPath, sizeof(FrLdrBootPath),
+                           "multi(0)disk(0)cdrom(%u)", PublicBootArcDisk);
+   }
+   else
+   {
+        ULONG BootPartition;
+        PARTITION_TABLE_ENTRY PartitionEntry;
+
+        /* This is a hard disk */
+        if (!UefiGetBootPartitionEntry(FrldrBootDrive, &PartitionEntry,
&BootPartition))
+        {
+            ERR("Failed to get boot partition entry\n");
+            return FALSE;
+        }
+
+        RtlStringCbPrintfA(FrLdrBootPath, sizeof(FrLdrBootPath),
+                           "multi(0)disk(0)rdisk(%u)partition(%lu)",
+                           PublicBootArcDisk, BootPartition);
+    }
+
+    return TRUE;
+}
+
+BOOLEAN
+UefiInitializeBootDevices(VOID)
+{
+    ULONG i = 0;
+
+    DiskReadBufferSize = EFI_PAGE_SIZE;
+    DiskReadBuffer = MmAllocateMemoryWithType(DiskReadBufferSize,
LoaderFirmwareTemporary);
+    UefiSetupBlockDevices();
+    UefiSetBootpath();
+
+    /* Add it, if it's a cdrom */
+   
GlobalSystemTable->BootServices->HandleProtocol(handles[UefiBootRootIdentifier],
&bioGuid, (void**)&bio);
+    if (bio->Media->RemovableMedia == TRUE && bio->Media->BlockSize
== 2048)
+    {
+        PMASTER_BOOT_RECORD Mbr;
+        PULONG Buffer;
+        ULONG Checksum = 0;
+        ULONG Signature;
+
+        /* Read the MBR */
+        if (!MachDiskReadLogicalSectors(FrldrBootDrive, 16ULL, 1, DiskReadBuffer))
+        {
+            ERR("Reading MBR failed\n");
+            return FALSE;
+        }
+
+        Buffer = (ULONG*)DiskReadBuffer;
+        Mbr = (PMASTER_BOOT_RECORD)DiskReadBuffer;
+
+        Signature = Mbr->Signature;
+        TRACE("Signature: %x\n", Signature);
+
+        /* Calculate the MBR checksum */
+        for (i = 0; i < 2048 / sizeof(ULONG); i++)
+        {
+            Checksum += Buffer[i];
+        }
+        Checksum = ~Checksum + 1;
+        TRACE("Checksum: %x\n", Checksum);
+
+        /* Fill out the ARC disk block */
+        AddReactOSArcDiskInfo(FrLdrBootPath, Signature, Checksum, TRUE);
+
+        FsRegisterDevice(FrLdrBootPath, &UefiDiskVtbl);
+        PcBiosDiskCount++; // This is not accounted for in the number of pre-enumerated
BIOS drives!
+        TRACE("Additional boot drive detected: 0x%02X\n",
(int)FrldrBootDrive);
+    }
+    return TRUE;
+}
+
+UCHAR
+UefiGetFloppyCount(VOID)
+{
+    /* No floppy for you for now... */
+    return 0;
+}
+
+BOOLEAN
+UefiDiskReadLogicalSectors(
+    IN UCHAR DriveNumber,
+    IN ULONGLONG SectorNumber,
+    IN ULONG SectorCount,
+    OUT PVOID Buffer)
+{
+    ULONG UefiDriveNumber;
+
+    UefiDriveNumber = InternalUefiDisk[DriveNumber - FIRST_BIOS_DISK].UefiRootNumber;
+    TRACE("UefiDiskReadLogicalSectors: DriveNumber: %d\n", UefiDriveNumber);
+    GlobalSystemTable->BootServices->HandleProtocol(handles[UefiDriveNumber],
&bioGuid, (void**)&bio);
+
+    /* Devices setup */
+    bio->ReadBlocks(bio, bio->Media->MediaId, SectorNumber, SectorCount *
bio->Media->BlockSize, Buffer);
+    return TRUE;
+}
+
+BOOLEAN
+UefiDiskGetDriveGeometry(UCHAR DriveNumber, PGEOMETRY Geometry)
+{
+    ULONG UefiDriveNumber;
+
+    UefiDriveNumber = InternalUefiDisk[DriveNumber - FIRST_BIOS_DISK].UefiRootNumber;
+    GlobalSystemTable->BootServices->HandleProtocol(handles[UefiDriveNumber],
&bioGuid, (void**)&bio);
+    Geometry->Cylinders = 1;      // Not relevant for the UEFI BIO protocol
+    Geometry->Heads = 1;          // Not relevant for the UEFI BIO protocol
+    Geometry->Sectors = bio->Media->LastBlock;        // Number of sectors per
track
+    Geometry->BytesPerSector = bio->Media->BlockSize; // Number of bytes per
sector
+
+    return TRUE;
+}
+
+ULONG
+UefiDiskGetCacheableBlockCount(UCHAR DriveNumber)
+{
+    ULONG UefiDriveNumber = InternalUefiDisk[DriveNumber -
FIRST_BIOS_DISK].UefiRootNumber;
+    TRACE("UefiDiskGetCacheableBlockCount: DriveNumber: %d\n",
UefiDriveNumber);
+
+    GlobalSystemTable->BootServices->HandleProtocol(handles[UefiDriveNumber],
&bioGuid, (void**)&bio);
+    return bio->Media->LastBlock;
+}
diff --git a/boot/freeldr/freeldr/uefi.cmake b/boot/freeldr/freeldr/uefi.cmake
index 94b5baa7630..0adb0a25f4b 100644
--- a/boot/freeldr/freeldr/uefi.cmake
+++ b/boot/freeldr/freeldr/uefi.cmake
@@ -14,11 +14,12 @@ include_directories(BEFORE
 list(APPEND UEFILDR_ARC_SOURCE
     ${FREELDR_ARC_SOURCE}
     arch/uefi/stubs.c
-    arch/uefi/uefisetup.c
-    arch/uefi/uefivid.c
-    arch/uefi/uefiutil.c
     arch/uefi/ueficon.c
+    arch/uefi/uefidisk.c
     arch/uefi/uefimem.c
+    arch/uefi/uefisetup.c
+    arch/uefi/uefiutil.c
+    arch/uefi/uefivid.c
     arch/vgafont.c)
 
 if(ARCH STREQUAL "i386")