C++ (Cpp) FatUnpackBios Examples

Example #1

File: fat.c Project: CSRedRat/reactos

NTSTATUS
FatMount (
    _In_ ULONG DeviceId,
    _In_ ULONG Unknown,
    _Out_ PBL_FILE_ENTRY* FileEntry
    )
{
    BL_DEVICE_INFORMATION DeviceInformation;
    ULONG UnknownFlag;
    NTSTATUS Status;
    PACKED_BOOT_SECTOR FatBootSector;
    BIOS_PARAMETER_BLOCK BiosBlock;

    /* Capture thing */
    BlDeviceGetInformation(DeviceId, &DeviceInformation);
    UnknownFlag = DeviceInformation.BlockDeviceInfo.Unknown;

    /* Set thing to 1 */
    DeviceInformation.BlockDeviceInfo.Unknown |= 1;
    BlDeviceSetInformation(DeviceId, &DeviceInformation);

    /* Read the boot sector */
    Status = BlDeviceReadAtOffset(DeviceId,
                                  sizeof(FatBootSector),
                                  0,
                                  &FatBootSector,
                                  NULL);

    /* Restore thing back */
    DeviceInformation.BlockDeviceInfo.Unknown = UnknownFlag;
    BlDeviceSetInformation(DeviceId, &DeviceInformation);
    if (!NT_SUCCESS(Status))
    {
        EfiPrintf(L"Failed reading drive: %lx\r\n", Status);
        return Status;
    }

    FatUnpackBios(&BiosBlock, &FatBootSector.PackedBpb);

    /* For now, quickly fail if this isn't FAT */
    if (FatBootSector.Jump[0] != 0xE9)
    {
        return STATUS_UNSUCCESSFUL;
    }

    EfiPrintf(L"Jump: %lx Bytes Per Sector: %d Sectors Per Cluster: %d Reserved: %d Fats: %d Sectors: %d Large Sectors: %d Media: %lx RootEntries: %d\r\n",
              FatBootSector.Jump[0],
              BiosBlock.BytesPerSector,
              BiosBlock.SectorsPerCluster,
              BiosBlock.ReservedSectors,
              BiosBlock.Fats,
              BiosBlock.Sectors,
              BiosBlock.LargeSectors,
              BiosBlock.Media,
              BiosBlock.RootEntries);
    return STATUS_NOT_IMPLEMENTED;
}

Example #2

File: fat.c Project: HBelusca/NasuTek-Odyssey

BOOLEAN
NTAPI
FsRecIsFatVolume(IN PPACKED_BOOT_SECTOR PackedBootSector)
{
    BIOS_PARAMETER_BLOCK Bpb;
    BOOLEAN Result = TRUE;
    PAGED_CODE();

    RtlZeroMemory(&Bpb, sizeof(BIOS_PARAMETER_BLOCK));

    /* Unpack the BPB and do a small fix up */
    FatUnpackBios(&Bpb, &PackedBootSector->PackedBpb);
    if (Bpb.Sectors) Bpb.LargeSectors = 0;

    /* Recognize jump */
    if ((PackedBootSector->Jump[0] != 0x49) &&
        (PackedBootSector->Jump[0] != 0xE9) &&
        (PackedBootSector->Jump[0] != 0xEB))
    {
        /* Fail */
        Result = FALSE;
    }
    else if ((Bpb.BytesPerSector != 128) &&
             (Bpb.BytesPerSector != 256) &&
             (Bpb.BytesPerSector != 512) &&
             (Bpb.BytesPerSector != 1024) &&
             (Bpb.BytesPerSector != 2048) &&
             (Bpb.BytesPerSector != 4096))
    {
        /* Fail */
        Result = FALSE;
    }
    else if ((Bpb.SectorsPerCluster != 1) &&
             (Bpb.SectorsPerCluster != 2) &&
             (Bpb.SectorsPerCluster != 4) &&
             (Bpb.SectorsPerCluster != 8) &&
             (Bpb.SectorsPerCluster != 16) &&
             (Bpb.SectorsPerCluster != 32) &&
             (Bpb.SectorsPerCluster != 64) &&
             (Bpb.SectorsPerCluster != 128))
    {
        /* Fail */
        Result = FALSE;
    }
    else if (!Bpb.ReservedSectors)
    {
        /* Fail */
        Result = FALSE;
    }
    else if (!(Bpb.Sectors) && !(Bpb.LargeSectors))
    {
        /* Fail */
        Result = FALSE;
    }
    else if ((Bpb.Media != 0x00) &&
             (Bpb.Media != 0x01) &&
             (Bpb.Media != 0xf0) &&
             (Bpb.Media != 0xf8) &&
             (Bpb.Media != 0xf9) &&
             (Bpb.Media != 0xfa) &&
             (Bpb.Media != 0xfb) &&
             (Bpb.Media != 0xfc) &&
             (Bpb.Media != 0xfd) &&
             (Bpb.Media != 0xfe) &&
             (Bpb.Media != 0xff))
    {
        /* Fail */
        Result = FALSE;
    }
    else if ((Bpb.SectorsPerFat) && !(Bpb.RootEntries))
    {
        /* Fail */
        Result = FALSE;
    }

    /* Return the result */
    return Result;
}