FvLib.c

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#include <Library/FvLib.h>
 
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
 
#define GET_OCCUPIED_SIZE(ActualSize, Alignment) \
  (ActualSize) + (((Alignment) - ((ActualSize) & ((Alignment) - 1))) & ((Alignment) - 1))
 
EFI_FFS_FILE_STATE
GetFileState (
  IN UINT8                ErasePolarity,
  IN EFI_FFS_FILE_HEADER  *FfsHeader
  )
{
  EFI_FFS_FILE_STATE  FileState;
  EFI_FFS_FILE_STATE  HighestBit;
 
  FileState = FfsHeader->State;
 
  if (ErasePolarity != 0) {
    FileState = (EFI_FFS_FILE_STATE) ~FileState;
  }
 
  HighestBit = 0x80;
  while (HighestBit != 0 && (HighestBit & FileState) == 0) {
    HighestBit >>= 1;
  }
 
  return HighestBit;
}
 
UINT8
CalculateHeaderChecksum (
  IN EFI_FFS_FILE_HEADER  *FileHeader
  )
{
  UINT8  *ptr;
  UINTN  Index;
  UINT8  Sum;
  UINTN  Size;
 
  Sum  = 0;
  ptr  = (UINT8 *)FileHeader;
  Size = IS_FFS_FILE2 (FileHeader) ? sizeof (EFI_FFS_FILE_HEADER2) : sizeof (EFI_FFS_FILE_HEADER);
 
  for (Index = 0; Index < Size - 3; Index += 4) {
    Sum = (UINT8)(Sum + ptr[Index]);
    Sum = (UINT8)(Sum + ptr[Index + 1]);
    Sum = (UINT8)(Sum + ptr[Index + 2]);
    Sum = (UINT8)(Sum + ptr[Index + 3]);
  }
 
  for ( ; Index < Size; Index++) {
    Sum = (UINT8)(Sum + ptr[Index]);
  }
 
  //
  // State field (since this indicates the different state of file).
  //
  Sum = (UINT8)(Sum - FileHeader->State);
  //
  // Checksum field of the file is not part of the header checksum.
  //
  Sum = (UINT8)(Sum - FileHeader->IntegrityCheck.Checksum.File);
 
  return Sum;
}
 
EFI_STATUS
EFIAPI
FfsFindNextFile (
  IN EFI_FV_FILETYPE             SearchType,
  IN EFI_FIRMWARE_VOLUME_HEADER  *FwVolHeader,
  IN OUT EFI_FFS_FILE_HEADER     **FileHeader
  )
{
  EFI_FIRMWARE_VOLUME_EXT_HEADER  *FvExtHeader;
 
  EFI_FFS_FILE_HEADER  *FfsFileHeader;
  UINT32               FileLength;
  UINT32               FileOccupiedSize;
  UINT32               FileOffset;
  UINT64               FvLength;
  UINT8                ErasePolarity;
  UINT8                FileState;
 
  FvLength = FwVolHeader->FvLength;
  if (FwVolHeader->Attributes & EFI_FVB2_ERASE_POLARITY) {
    ErasePolarity = 1;
  } else {
    ErasePolarity = 0;
  }
 
  //
  // If FileHeader is not specified (NULL) start with the first file in the
  // firmware volume.  Otherwise, start from the FileHeader.
  //
  if (*FileHeader == NULL) {
    if (FwVolHeader->ExtHeaderOffset != 0) {
      FvExtHeader = (EFI_FIRMWARE_VOLUME_EXT_HEADER *)((UINT8 *)FwVolHeader +
                                                       FwVolHeader->ExtHeaderOffset);
 
      FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FvExtHeader +
                                              FvExtHeader->ExtHeaderSize);
    } else {
      FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FwVolHeader +
                                              FwVolHeader->HeaderLength);
    }
 
    FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINTN)FwVolHeader +
                                            ALIGN_VALUE (
                                              (UINTN)FfsFileHeader -
                                              (UINTN)FwVolHeader,
                                              8
                                              ));
  } else {
    //
    // Length is 24 bits wide so mask upper 8 bits
    // FileLength is adjusted to FileOccupiedSize as it is 8 byte aligned.
    //
    FileLength = IS_FFS_FILE2 (*FileHeader) ?
                 FFS_FILE2_SIZE (*FileHeader) : FFS_FILE_SIZE (*FileHeader);
    FileOccupiedSize = GET_OCCUPIED_SIZE (FileLength, 8);
    FfsFileHeader    = (EFI_FFS_FILE_HEADER *)((UINT8 *)*FileHeader + FileOccupiedSize);
  }
 
  FileOffset = (UINT32)((UINT8 *)FfsFileHeader - (UINT8 *)FwVolHeader);
 
  while ((UINT64)FileOffset < (FvLength - sizeof (EFI_FFS_FILE_HEADER))) {
    //
    // Get FileState which is the highest bit of the State
    //
    FileState = GetFileState (ErasePolarity, FfsFileHeader);
 
    switch (FileState) {
      case EFI_FILE_HEADER_INVALID:
        if (IS_FFS_FILE2 (FfsFileHeader)) {
          FileOffset   += sizeof (EFI_FFS_FILE_HEADER2);
          FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + sizeof (EFI_FFS_FILE_HEADER2));
        } else {
          FileOffset   += sizeof (EFI_FFS_FILE_HEADER);
          FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + sizeof (EFI_FFS_FILE_HEADER));
        }
 
        break;
 
      case EFI_FILE_DATA_VALID:
      case EFI_FILE_MARKED_FOR_UPDATE:
        if (CalculateHeaderChecksum (FfsFileHeader) == 0) {
          FileLength = IS_FFS_FILE2 (FfsFileHeader) ?
                       FFS_FILE2_SIZE (FfsFileHeader) : FFS_FILE_SIZE (FfsFileHeader);
          FileOccupiedSize = GET_OCCUPIED_SIZE (FileLength, 8);
 
          if ((SearchType == FfsFileHeader->Type) || (SearchType == EFI_FV_FILETYPE_ALL)) {
            *FileHeader = FfsFileHeader;
 
            return EFI_SUCCESS;
          }
 
          FileOffset   += FileOccupiedSize;
          FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + FileOccupiedSize);
        } else {
          return EFI_NOT_FOUND;
        }
 
        break;
 
      case EFI_FILE_DELETED:
        FileLength = IS_FFS_FILE2 (FfsFileHeader) ?
                     FFS_FILE2_SIZE (FfsFileHeader) : FFS_FILE_SIZE (FfsFileHeader);
        FileOccupiedSize = GET_OCCUPIED_SIZE (FileLength, 8);
        FileOffset      += FileOccupiedSize;
        FfsFileHeader    = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + FileOccupiedSize);
        break;
 
      default:
        return EFI_NOT_FOUND;
    }
  }
 
  return EFI_NOT_FOUND;
}
 
EFI_STATUS
EFIAPI
FindFfsSectionInSections (
  IN  VOID                       *Sections,
  IN  UINTN                      SizeOfSections,
  IN  EFI_SECTION_TYPE           SectionType,
  OUT EFI_COMMON_SECTION_HEADER  **FoundSection
  )
{
  EFI_PHYSICAL_ADDRESS       CurrentAddress;
  UINT32                     Size;
  EFI_PHYSICAL_ADDRESS       EndOfSections;
  EFI_COMMON_SECTION_HEADER  *Section;
  EFI_PHYSICAL_ADDRESS       EndOfSection;
 
  //
  // Loop through the FFS file sections
  //
  EndOfSection  = (EFI_PHYSICAL_ADDRESS)(UINTN)Sections;
  EndOfSections = EndOfSection + SizeOfSections;
  for ( ; ;) {
    if (EndOfSection == EndOfSections) {
      break;
    }
 
    CurrentAddress = EndOfSection;
 
    Section = (EFI_COMMON_SECTION_HEADER *)(UINTN)CurrentAddress;
 
    Size = IS_SECTION2 (Section) ? SECTION2_SIZE (Section) : SECTION_SIZE (Section);
    if (Size < sizeof (*Section)) {
      return EFI_VOLUME_CORRUPTED;
    }
 
    EndOfSection = CurrentAddress + Size;
    if (EndOfSection > EndOfSections) {
      return EFI_VOLUME_CORRUPTED;
    }
 
    Size = GET_OCCUPIED_SIZE (Size, 4);
 
    //
    // Look for the requested section type
    //
    if (Section->Type == SectionType) {
      *FoundSection = Section;
      return EFI_SUCCESS;
    }
  }
 
  return EFI_NOT_FOUND;
}
 
EFI_STATUS
EFIAPI
FfsFindSection (
  IN EFI_SECTION_TYPE               SectionType,
  IN EFI_FFS_FILE_HEADER            *FfsFileHeader,
  IN OUT EFI_COMMON_SECTION_HEADER  **SectionHeader
  )
{
  UINT32                     FileSize;
  EFI_COMMON_SECTION_HEADER  *Section;
  EFI_STATUS                 Status;
 
  //
  // Size is 24 bits wide so mask upper 8 bits.
  //    Does not include FfsFileHeader header size
  // FileSize is adjusted to FileOccupiedSize as it is 8 byte aligned.
  //
  if (IS_FFS_FILE2 (FfsFileHeader)) {
    Section  = (EFI_COMMON_SECTION_HEADER *)((EFI_FFS_FILE_HEADER2 *)FfsFileHeader + 1);
    FileSize = FFS_FILE2_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER2);
  } else {
    Section  = (EFI_COMMON_SECTION_HEADER *)(FfsFileHeader + 1);
    FileSize = FFS_FILE_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER);
  }
 
  Status = FindFfsSectionInSections (
             Section,
             FileSize,
             SectionType,
             SectionHeader
             );
  return Status;
}
 
EFI_STATUS
EFIAPI
FfsFindSectionData (
  IN EFI_SECTION_TYPE     SectionType,
  IN EFI_FFS_FILE_HEADER  *FfsFileHeader,
  IN OUT VOID             **SectionData,
  IN OUT UINTN            *SectionDataSize
  )
{
  UINT32                     FileSize;
  EFI_COMMON_SECTION_HEADER  *Section;
  UINT32                     SectionLength;
  UINT32                     ParsedLength;
 
  //
  // Size is 24 bits wide so mask upper 8 bits.
  // Does not include FfsFileHeader header size
  // FileSize is adjusted to FileOccupiedSize as it is 8 byte aligned.
  //
  if (IS_FFS_FILE2 (FfsFileHeader)) {
    Section  = (EFI_COMMON_SECTION_HEADER *)((EFI_FFS_FILE_HEADER2 *)FfsFileHeader + 1);
    FileSize = FFS_FILE2_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER2);
  } else {
    Section  = (EFI_COMMON_SECTION_HEADER *)(FfsFileHeader + 1);
    FileSize = FFS_FILE_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER);
  }
 
  *SectionData = NULL;
  ParsedLength = 0;
  while (ParsedLength < FileSize) {
    if (Section->Type == SectionType) {
      if (IS_SECTION2 (Section)) {
        *SectionData     = (VOID *)((EFI_COMMON_SECTION_HEADER2 *)Section + 1);
        *SectionDataSize = SECTION2_SIZE (Section) - sizeof (EFI_COMMON_SECTION_HEADER2);
      } else {
        *SectionData     = (VOID *)(Section + 1);
        *SectionDataSize = SECTION_SIZE (Section) - sizeof (EFI_COMMON_SECTION_HEADER);
      }
 
      return EFI_SUCCESS;
    }
 
    //
    // Size is 24 bits wide so mask upper 8 bits.
    // SectionLength is adjusted it is 4 byte aligned.
    // Go to the next section
    //
    SectionLength = IS_SECTION2 (Section) ? SECTION2_SIZE (Section) : SECTION_SIZE (Section);
    SectionLength = GET_OCCUPIED_SIZE (SectionLength, 4);
 
    ParsedLength += SectionLength;
    Section       = (EFI_COMMON_SECTION_HEADER *)((UINT8 *)Section + SectionLength);
  }
 
  return EFI_NOT_FOUND;
}