ElTorito.c

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#include "Partition.h"
 
EFI_STATUS
PartitionInstallElToritoChildHandles (
  IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
  IN  EFI_HANDLE                   Handle,
  IN  EFI_DISK_IO_PROTOCOL         *DiskIo,
  IN  EFI_DISK_IO2_PROTOCOL        *DiskIo2,
  IN  EFI_BLOCK_IO_PROTOCOL        *BlockIo,
  IN  EFI_BLOCK_IO2_PROTOCOL       *BlockIo2,
  IN  EFI_DEVICE_PATH_PROTOCOL     *DevicePath
  )
{
  EFI_STATUS                     Status;
  UINT64                         VolDescriptorOffset;
  UINT32                         Lba2KB;
  EFI_BLOCK_IO_MEDIA             *Media;
  CDROM_VOLUME_DESCRIPTOR        *VolDescriptor;
  ELTORITO_CATALOG               *Catalog;
  UINTN                          Check;
  UINTN                          Index;
  UINTN                          BootEntry;
  UINTN                          MaxIndex;
  UINT16                         *CheckBuffer;
  CDROM_DEVICE_PATH              CdDev;
  UINT32                         SubBlockSize;
  UINT32                         SectorCount;
  EFI_STATUS                     Found;
  UINT32                         VolSpaceSize;
  EFI_PARTITION_INFO_PROTOCOL    PartitionInfo;
  APPLE_PARTITION_INFO_PROTOCOL  ApplePartitionInfo;
 
  Found = EFI_NOT_FOUND;
  Media = BlockIo->Media;
 
  VolSpaceSize = 0;
 
  //
  // CD_ROM has the fixed block size as 2048 bytes (SIZE_2KB)
  //
 
  // If the ISO image has been copied onto a different storage media
  // then the block size might be different (eg: USB).
  // Ensure 2048 (SIZE_2KB) is a multiple of block size
  if (((SIZE_2KB % Media->BlockSize) != 0) || (Media->BlockSize > SIZE_2KB)) {
    return EFI_NOT_FOUND;
  }
 
  VolDescriptor = AllocatePool ((UINTN)SIZE_2KB);
 
  if (VolDescriptor == NULL) {
    return EFI_NOT_FOUND;
  }
 
  Catalog = (ELTORITO_CATALOG *)VolDescriptor;
 
  //
  // Loop: handle one volume descriptor per time
  //       The ISO-9660 volume descriptor starts at 32k on the media
  //
  for (VolDescriptorOffset = SIZE_32KB;
       VolDescriptorOffset <= MultU64x32 (Media->LastBlock, Media->BlockSize);
       VolDescriptorOffset += SIZE_2KB)
  {
    Status = DiskIo->ReadDisk (
                       DiskIo,
                       Media->MediaId,
                       VolDescriptorOffset,
                       SIZE_2KB,
                       VolDescriptor
                       );
    if (EFI_ERROR (Status)) {
      Found = 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,
    // the 32-bit numerical values is stored in Both-byte orders
    //
    if (VolDescriptor->PrimaryVolume.Type == CDVOL_TYPE_CODED) {
      VolSpaceSize = VolDescriptor->PrimaryVolume.VolSpaceSize[0];
    }
 
    //
    // 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
    // The LBA unit used by El Torito boot catalog is 2KB unit
    //
    Lba2KB = UNPACK_INT32 (VolDescriptor->BootRecordVolume.EltCatalog);
    // Ensure the LBA (in 2KB unit) fits into our media
    if (Lba2KB * (SIZE_2KB / Media->BlockSize) > Media->LastBlock) {
      continue;
    }
 
    Status = DiskIo->ReadDisk (
                       DiskIo,
                       Media->MediaId,
                       MultU64x32 (Lba2KB, SIZE_2KB),
                       SIZE_2KB,
                       Catalog
                       );
    if (EFI_ERROR (Status)) {
      DEBUG ((EFI_D_ERROR, "EltCheckDevice: error reading catalog %r\n", 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)) {
      DEBUG ((EFI_D_ERROR, "EltCheckBootCatalog: El Torito boot catalog header IDs not correct\n"));
      continue;
    }
 
    Check       = 0;
    CheckBuffer = (UINT16 *)Catalog;
    for (Index = 0; Index < sizeof (ELTORITO_CATALOG) / sizeof (UINT16); Index += 1) {
      Check += CheckBuffer[Index];
    }
 
    if ((Check & 0xFFFF) != 0) {
      DEBUG ((EFI_D_ERROR, "EltCheckBootCatalog: El Torito boot catalog header checksum failed\n"));
      continue;
    }
 
    MaxIndex = Media->BlockSize / sizeof (ELTORITO_CATALOG);
    for (Index = 1, BootEntry = 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 = Media->BlockSize;
          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:
          DEBUG ((EFI_D_INIT, "EltCheckDevice: unsupported El Torito boot media type %x\n", Catalog->Boot.MediaType));
          SectorCount  = 0;
          SubBlockSize = Media->BlockSize;
          break;
      }
 
      //
      // Create child device handle
      //
      CdDev.Header.Type    = MEDIA_DEVICE_PATH;
      CdDev.Header.SubType = MEDIA_CDROM_DP;
      SetDevicePathNodeLength (&CdDev.Header, sizeof (CdDev));
 
      if (Index == 1) {
        //
        // This is the initial/default entry
        //
        BootEntry = 0;
      }
 
      CdDev.BootEntry = (UINT32)BootEntry;
      BootEntry++;
      CdDev.PartitionStart = Catalog->Boot.Lba * (SIZE_2KB / Media->BlockSize);
      if (SectorCount < 2) {
        //
        // When the SectorCount < 2, set the Partition as the whole CD.
        //
        if (VolSpaceSize * (SIZE_2KB / Media->BlockSize) > (Media->LastBlock + 1)) {
          CdDev.PartitionSize = (UINT32)(Media->LastBlock - Catalog->Boot.Lba * (SIZE_2KB / Media->BlockSize) + 1);
        } else {
          CdDev.PartitionSize = (UINT32)(VolSpaceSize - Catalog->Boot.Lba) * (SIZE_2KB / Media->BlockSize);
        }
      } else {
        CdDev.PartitionSize = DivU64x32 (
                                MultU64x32 (
                                  SectorCount * (SIZE_2KB / Media->BlockSize),
                                  SubBlockSize
                                  ) + Media->BlockSize - 1,
                                Media->BlockSize
                                );
      }
 
      ZeroMem (&PartitionInfo, sizeof (EFI_PARTITION_INFO_PROTOCOL));
      PartitionInfo.Revision = EFI_PARTITION_INFO_PROTOCOL_REVISION;
      PartitionInfo.Type     = PARTITION_TYPE_OTHER;
 
      ZeroMem (&ApplePartitionInfo, sizeof (APPLE_PARTITION_INFO_PROTOCOL));
      ApplePartitionInfo.Revision        = APPLE_PARTITION_INFO_REVISION;
      ApplePartitionInfo.PartitionNumber = CdDev.BootEntry;
      ApplePartitionInfo.PartitionStart  = CdDev.PartitionStart;
      ApplePartitionInfo.PartitionSize   = CdDev.PartitionSize;
 
      Status = PartitionInstallChildHandle (
                 This,
                 Handle,
                 DiskIo,
                 DiskIo2,
                 BlockIo,
                 BlockIo2,
                 DevicePath,
                 (EFI_DEVICE_PATH_PROTOCOL *)&CdDev,
                 &PartitionInfo,
                 &ApplePartitionInfo,
                 Catalog->Boot.Lba * (SIZE_2KB / Media->BlockSize),
                 Catalog->Boot.Lba * (SIZE_2KB / Media->BlockSize) + CdDev.PartitionSize - 1,
                 SubBlockSize,
                 NULL
                 );
      if (!EFI_ERROR (Status)) {
        Found = EFI_SUCCESS;
      }
    }
  }
 
  FreePool (VolDescriptor);
 
  return Found;
}