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;
}
NTSTATUS
BlFileOpen (
_In_ ULONG DeviceId,
_In_ PWCHAR FileName,
_In_ ULONG Flags,
_Out_ PULONG FileId
)
{
NTSTATUS Status;
PBL_FILE_ENTRY FileEntry;
BL_DEVICE_INFORMATION DeviceInformation;
/* Make sure we have a valid file name, access flags and parameters */
if (!(FileName) ||
(*FileName != OBJ_NAME_PATH_SEPARATOR) ||
!(FileId) ||
!(Flags & (BL_FILE_READ_ACCESS | BL_FILE_WRITE_ACCESS)))
{
EfiPrintf(L"Invalid file options\r\n");
return STATUS_INVALID_PARAMETER;
}
/* Get information on the underlying device */
Status = BlDeviceGetInformation(DeviceId, &DeviceInformation);
if (!NT_SUCCESS(Status))
{
EfiPrintf(L"Get device info failed: %lx\r\n", Status);
return Status;
}
/* Make sure it's a device that can host files */
if ((DeviceInformation.DeviceType != DiskDevice) &&
(DeviceInformation.DeviceType != LegacyPartitionDevice) &&
(DeviceInformation.DeviceType != UdpDevice))
{
EfiPrintf(L"Invalid device type\r\n");
return STATUS_INVALID_PARAMETER;
}
/* Open a file on this device, creating one if needed */
Status = FileIoOpen(DeviceId,
FileName,
Flags,
0,
FileTableCompareWithSameAttributes,
&FileEntry);
if (NT_SUCCESS(Status))
{
/* Return the file ID back to the caller */
EfiPrintf(L"File opened: %lx\r\n", FileEntry->FileId);
*FileId = FileEntry->FileId;
}
/* All good */
return Status;
}
NTSTATUS
BlFileReadEx (
_In_ ULONG FileId,
_Out_ PVOID Buffer,
_In_ ULONG Size,
_Out_ PULONG BytesReturned,
_In_ ULONG Flags
)
{
PBL_FILE_ENTRY FileEntry;
NTSTATUS Status;
ULONG OldUnknown, RequiredSize;
BOOLEAN ChangedUnknown;
BL_DEVICE_INFORMATION DeviceInfo;
BL_FILE_INFORMATION fileInfo;
/* Initialize variables */
RtlZeroMemory(&DeviceInfo, sizeof(DeviceInfo));
OldUnknown = 0;
ChangedUnknown = FALSE;
/* Bail out if there's no buffer */
if (!Buffer)
{
return STATUS_INVALID_PARAMETER;
}
/* Bail out of the file ID is invalid */
if (FileId > FileEntries)
{
return STATUS_INVALID_PARAMETER;
}
/* Bail out if there's no file opened for read access */
FileEntry = FileTable[FileId];
if (!(FileEntry) ||
!(FileEntry->Flags & (BL_FILE_ENTRY_OPENED | BL_FILE_ENTRY_READ_ACCESS)))
{
return STATUS_INVALID_PARAMETER;
}
/* Bail out if we can't read the file's information */
Status = BlFileGetInformation(FileId, &fileInfo);
if (!NT_SUCCESS(Status))
{
return Status;
}
/* Ensure the read attempt is valid, and fix up the size if needed */
RequiredSize = Size;
Status = FileInformationCheck(&fileInfo,
FALSE,
&RequiredSize,
BytesReturned,
&RequiredSize);
if (!NT_SUCCESS(Status))
{
/* Invalid or illegal read attempt */
return Status;
}
/* Is there anything left to read after all? */
if (RequiredSize)
{
/* Check if flags 2 or 4 are set */
if ((Flags & 2) || (Flags & 4))
{
/* Check if this is a disk or partition device */
BlDeviceGetInformation(FileEntry->DeviceId, &DeviceInfo);
if ((DeviceInfo.DeviceType == DiskDevice) ||
(DeviceInfo.DeviceType == LegacyPartitionDevice))
{
/* Check if request flags are incompatible with device flags */
if ((!(DeviceInfo.BlockDeviceInfo.Unknown & 1) && (Flags & 2)) ||
(!(DeviceInfo.BlockDeviceInfo.Unknown & 2) && (Flags & 4)))
{
/* We're going to change the device flags */
ChangedUnknown = TRUE;
/* Set unknown flag 1 for request flag 2 */
if (Flags & 2)
{
DeviceInfo.BlockDeviceInfo.Unknown |= 1;
}
/* Set unknown flag 2 for request flag 4 */
if (Flags & 4)
{
DeviceInfo.BlockDeviceInfo.Unknown |= 2;
}
/* Save the new device flags */
BlDeviceSetInformation(FileEntry->DeviceId, &DeviceInfo);
}
}
}
/* Issue the read to the underlying file system */
Status = FileEntry->Callbacks.Read(FileEntry,
Buffer,
RequiredSize,
BytesReturned);
if (!NT_SUCCESS(Status))
{
/* Don't update the bytes read on failure */
RequiredSize = 0;
}
}
else
{
/* There's nothing to do, return success and 0 bytes */
Status = STATUS_SUCCESS;
if (BytesReturned)
{
*BytesReturned = 0;
}
}
/* Increment the number of bytes read */
FileEntry->TotalBytesRead += RequiredSize;
/* Check if the unknown flag on the device was changed during this routine */
if (ChangedUnknown)
{
/* Reset it back to its original value */
DeviceInfo.BlockDeviceInfo.Unknown = OldUnknown;
BlDeviceSetInformation(FileEntry->DeviceId, &DeviceInfo);
}
/* Return the final status */
return Status;
}
