diff options
Diffstat (limited to 'BaseTools/Source/C/Common/FvLib.c')
| -rw-r--r-- | BaseTools/Source/C/Common/FvLib.c | 851 |
1 files changed, 851 insertions, 0 deletions
diff --git a/BaseTools/Source/C/Common/FvLib.c b/BaseTools/Source/C/Common/FvLib.c new file mode 100644 index 0000000000..1b289d83cd --- /dev/null +++ b/BaseTools/Source/C/Common/FvLib.c @@ -0,0 +1,851 @@ +/** @file
+
+Copyright (c) 2004 - 2008, Intel Corporation. All rights reserved.<BR>
+This program and the accompanying materials
+are licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution. The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+Module Name:
+
+ FvLib.c
+
+Abstract:
+
+ These functions assist in parsing and manipulating a Firmware Volume.
+
+**/
+
+//
+// Include files
+//
+#include "FvLib.h"
+#include "CommonLib.h"
+#include "EfiUtilityMsgs.h"
+
+//
+// Module global variables
+//
+EFI_FIRMWARE_VOLUME_HEADER *mFvHeader = NULL;
+UINT32 mFvLength = 0;
+
+//
+// External function implementations
+//
+EFI_STATUS
+InitializeFvLib (
+ IN VOID *Fv,
+ IN UINT32 FvLength
+ )
+/*++
+
+Routine Description:
+
+ This initializes the FV lib with a pointer to the FV and length. It does not
+ verify the FV in any way.
+
+Arguments:
+
+ Fv Buffer containing the FV.
+ FvLength Length of the FV
+
+Returns:
+
+ EFI_SUCCESS Function Completed successfully.
+ EFI_INVALID_PARAMETER A required parameter was NULL.
+
+--*/
+{
+ //
+ // Verify input arguments
+ //
+ if (Fv == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ mFvHeader = (EFI_FIRMWARE_VOLUME_HEADER *) Fv;
+ mFvLength = FvLength;
+
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+GetFvHeader (
+ OUT EFI_FIRMWARE_VOLUME_HEADER **FvHeader,
+ OUT UINT32 *FvLength
+ )
+/*++
+
+Routine Description:
+
+ This function returns a pointer to the current FV and the size.
+
+Arguments:
+
+ FvHeader Pointer to the FV buffer.
+ FvLength Length of the FV
+
+Returns:
+
+ EFI_SUCCESS Function Completed successfully.
+ EFI_INVALID_PARAMETER A required parameter was NULL.
+ EFI_ABORTED The library needs to be initialized.
+
+--*/
+{
+ //
+ // Verify library has been initialized.
+ //
+ if (mFvHeader == NULL || mFvLength == 0) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify input arguments
+ //
+ if (FvHeader == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ *FvHeader = mFvHeader;
+ *FvLength = mFvLength;
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+GetNextFile (
+ IN EFI_FFS_FILE_HEADER *CurrentFile,
+ OUT EFI_FFS_FILE_HEADER **NextFile
+ )
+/*++
+
+Routine Description:
+
+ This function returns the next file. If the current file is NULL, it returns
+ the first file in the FV. If the function returns EFI_SUCCESS and the file
+ pointer is NULL, then there are no more files in the FV.
+
+Arguments:
+
+ CurrentFile Pointer to the current file, must be within the current FV.
+ NextFile Pointer to the next file in the FV.
+
+Returns:
+
+ EFI_SUCCESS Function completed successfully.
+ EFI_INVALID_PARAMETER A required parameter was NULL or is out of range.
+ EFI_ABORTED The library needs to be initialized.
+
+--*/
+{
+ EFI_STATUS Status;
+
+ //
+ // Verify library has been initialized.
+ //
+ if (mFvHeader == NULL || mFvLength == 0) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify input arguments
+ //
+ if (NextFile == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+ //
+ // Verify FV header
+ //
+ Status = VerifyFv (mFvHeader);
+ if (EFI_ERROR (Status)) {
+ return EFI_ABORTED;
+ }
+ //
+ // Get first file
+ //
+ if (CurrentFile == NULL) {
+ CurrentFile = (EFI_FFS_FILE_HEADER *) ((UINTN) mFvHeader + mFvHeader->HeaderLength);
+
+ //
+ // Verify file is valid
+ //
+ Status = VerifyFfsFile (CurrentFile);
+ if (EFI_ERROR (Status)) {
+ //
+ // no files in this FV
+ //
+ *NextFile = NULL;
+ return EFI_SUCCESS;
+ } else {
+ //
+ // Verify file is in this FV.
+ //
+ if ((UINTN) CurrentFile + GetLength (CurrentFile->Size) > (UINTN) mFvHeader + mFvLength) {
+ *NextFile = NULL;
+ return EFI_SUCCESS;
+ }
+
+ *NextFile = CurrentFile;
+ return EFI_SUCCESS;
+ }
+ }
+ //
+ // Verify current file is in range
+ //
+ if (((UINTN) CurrentFile < (UINTN) mFvHeader + mFvHeader->HeaderLength) ||
+ ((UINTN) CurrentFile + GetLength (CurrentFile->Size) > (UINTN) mFvHeader + mFvLength)
+ ) {
+ return EFI_INVALID_PARAMETER;
+ }
+ //
+ // Get next file, compensate for 8 byte alignment if necessary.
+ //
+ *NextFile = (EFI_FFS_FILE_HEADER *) ((((UINTN) CurrentFile - (UINTN) mFvHeader + GetLength (CurrentFile->Size) + 0x07) & (-1 << 3)) + (UINT8 *) mFvHeader);
+
+ //
+ // Verify file is in this FV.
+ //
+ if (((UINTN) *NextFile + sizeof (EFI_FFS_FILE_HEADER) >= (UINTN) mFvHeader + mFvLength) ||
+ ((UINTN) *NextFile + GetLength ((*NextFile)->Size) > (UINTN) mFvHeader + mFvLength)
+ ) {
+ *NextFile = NULL;
+ return EFI_SUCCESS;
+ }
+ //
+ // Verify file is valid
+ //
+ Status = VerifyFfsFile (*NextFile);
+ if (EFI_ERROR (Status)) {
+ //
+ // no more files in this FV
+ //
+ *NextFile = NULL;
+ return EFI_SUCCESS;
+ }
+
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+GetFileByName (
+ IN EFI_GUID *FileName,
+ OUT EFI_FFS_FILE_HEADER **File
+ )
+/*++
+
+Routine Description:
+
+ Find a file by name. The function will return NULL if the file is not found.
+
+Arguments:
+
+ FileName The GUID file name of the file to search for.
+ File Return pointer. In the case of an error, contents are undefined.
+
+Returns:
+
+ EFI_SUCCESS The function completed successfully.
+ EFI_ABORTED An error was encountered.
+ EFI_INVALID_PARAMETER One of the parameters was NULL.
+
+--*/
+{
+ EFI_FFS_FILE_HEADER *CurrentFile;
+ EFI_STATUS Status;
+ CHAR8 FileGuidString[80];
+
+ //
+ // Verify library has been initialized.
+ //
+ if (mFvHeader == NULL || mFvLength == 0) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify input parameters
+ //
+ if (FileName == NULL || File == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+ //
+ // File Guid String Name
+ //
+ PrintGuidToBuffer (FileName, (UINT8 *)FileGuidString, sizeof (FileGuidString), TRUE);
+ //
+ // Verify FV header
+ //
+ Status = VerifyFv (mFvHeader);
+ if (EFI_ERROR (Status)) {
+ return EFI_ABORTED;
+ }
+ //
+ // Get the first file
+ //
+ Status = GetNextFile (NULL, &CurrentFile);
+ if (EFI_ERROR (Status)) {
+ Error (NULL, 0, 0003, "error parsing FV image", "FFS file with Guid %s can't be found", FileGuidString);
+ return EFI_ABORTED;
+ }
+ //
+ // Loop as long as we have a valid file
+ //
+ while (CurrentFile) {
+ if (!CompareGuid (&CurrentFile->Name, FileName)) {
+ *File = CurrentFile;
+ return EFI_SUCCESS;
+ }
+
+ Status = GetNextFile (CurrentFile, &CurrentFile);
+ if (EFI_ERROR (Status)) {
+ Error (NULL, 0, 0003, "error parsing FV image", "FFS file with Guid %s can't be found", FileGuidString);
+ return EFI_ABORTED;
+ }
+ }
+ //
+ // File not found in this FV.
+ //
+ *File = NULL;
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+GetFileByType (
+ IN EFI_FV_FILETYPE FileType,
+ IN UINTN Instance,
+ OUT EFI_FFS_FILE_HEADER **File
+ )
+/*++
+
+Routine Description:
+
+ Find a file by type and instance. An instance of 1 is the first instance.
+ The function will return NULL if a matching file cannot be found.
+ File type EFI_FV_FILETYPE_ALL means any file type is valid.
+
+Arguments:
+
+ FileType Type of file to search for.
+ Instance Instace of the file type to return.
+ File Return pointer. In the case of an error, contents are undefined.
+
+Returns:
+
+ EFI_SUCCESS The function completed successfully.
+ EFI_ABORTED An error was encountered.
+ EFI_INVALID_PARAMETER One of the parameters was NULL.
+
+--*/
+{
+ EFI_FFS_FILE_HEADER *CurrentFile;
+ EFI_STATUS Status;
+ UINTN FileCount;
+
+ //
+ // Verify library has been initialized.
+ //
+ if (mFvHeader == NULL || mFvLength == 0) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify input parameters
+ //
+ if (File == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+ //
+ // Verify FV header
+ //
+ Status = VerifyFv (mFvHeader);
+ if (EFI_ERROR (Status)) {
+ return EFI_ABORTED;
+ }
+ //
+ // Initialize the number of matching files found.
+ //
+ FileCount = 0;
+
+ //
+ // Get the first file
+ //
+ Status = GetNextFile (NULL, &CurrentFile);
+ if (EFI_ERROR (Status)) {
+ Error (NULL, 0, 0003, "error parsing FV image", "FFS file with FileType 0x%x can't be found", FileType);
+ return EFI_ABORTED;
+ }
+ //
+ // Loop as long as we have a valid file
+ //
+ while (CurrentFile) {
+ if (FileType == EFI_FV_FILETYPE_ALL || CurrentFile->Type == FileType) {
+ FileCount++;
+ }
+
+ if (FileCount == Instance) {
+ *File = CurrentFile;
+ return EFI_SUCCESS;
+ }
+
+ Status = GetNextFile (CurrentFile, &CurrentFile);
+ if (EFI_ERROR (Status)) {
+ Error (NULL, 0, 0003, "error parsing FV image", "FFS file with FileType 0x%x can't be found", FileType);
+ return EFI_ABORTED;
+ }
+ }
+
+ *File = NULL;
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+SearchSectionByType (
+ IN EFI_FILE_SECTION_POINTER FirstSection,
+ IN UINT8 *SearchEnd,
+ IN EFI_SECTION_TYPE SectionType,
+ IN OUT UINTN *StartIndex,
+ IN UINTN Instance,
+ OUT EFI_FILE_SECTION_POINTER *Section
+ )
+/*++
+
+Routine Description:
+
+ Helper function to search a sequence of sections from the section pointed
+ by FirstSection to SearchEnd for the Instance-th section of type SectionType.
+ The current counter is saved in StartIndex and when the section is found, it's
+ saved in Section. GUID-defined sections, if special processing is not required,
+ are searched recursively in a depth-first manner.
+
+Arguments:
+
+ FirstSection The first section to start searching from.
+ SearchEnd The end address to stop search.
+ SectionType The type of section to search.
+ StartIndex The current counter is saved.
+ Instance The requested n-th section number.
+ Section The found section returned.
+
+Returns:
+
+ EFI_SUCCESS The function completed successfully.
+ EFI_NOT_FOUND The section is not found.
+--*/
+{
+ EFI_FILE_SECTION_POINTER CurrentSection;
+ EFI_FILE_SECTION_POINTER InnerSection;
+ EFI_STATUS Status;
+ UINTN SectionSize;
+
+ CurrentSection = FirstSection;
+
+ while ((UINTN) CurrentSection.CommonHeader < (UINTN) SearchEnd) {
+ if (CurrentSection.CommonHeader->Type == SectionType) {
+ (*StartIndex)++;
+ }
+
+ if (*StartIndex == Instance) {
+ *Section = CurrentSection;
+ return EFI_SUCCESS;
+ }
+ //
+ // If the requesting section is not GUID-defined and
+ // we find a GUID-defined section that doesn't need
+ // special processing, go ahead to search the requesting
+ // section inside the GUID-defined section.
+ //
+ if (SectionType != EFI_SECTION_GUID_DEFINED &&
+ CurrentSection.CommonHeader->Type == EFI_SECTION_GUID_DEFINED &&
+ !(CurrentSection.GuidDefinedSection->Attributes & EFI_GUIDED_SECTION_PROCESSING_REQUIRED)) {
+ InnerSection.CommonHeader = (EFI_COMMON_SECTION_HEADER *)
+ ((UINTN) CurrentSection.CommonHeader + CurrentSection.GuidDefinedSection->DataOffset);
+ SectionSize = CurrentSection.CommonHeader->Size[0] +
+ (CurrentSection.CommonHeader->Size[1] << 8) +
+ (CurrentSection.CommonHeader->Size[2] << 16);
+ Status = SearchSectionByType (
+ InnerSection,
+ (UINT8 *) ((UINTN) CurrentSection.CommonHeader + SectionSize),
+ SectionType,
+ StartIndex,
+ Instance,
+ Section
+ );
+ if (!EFI_ERROR (Status)) {
+ return EFI_SUCCESS;
+ }
+ }
+ //
+ // Find next section (including compensating for alignment issues.
+ //
+ CurrentSection.CommonHeader = (EFI_COMMON_SECTION_HEADER *) ((((UINTN) CurrentSection.CommonHeader) + GetLength (CurrentSection.CommonHeader->Size) + 0x03) & (-1 << 2));
+ }
+
+ return EFI_NOT_FOUND;
+}
+
+EFI_STATUS
+GetSectionByType (
+ IN EFI_FFS_FILE_HEADER *File,
+ IN EFI_SECTION_TYPE SectionType,
+ IN UINTN Instance,
+ OUT EFI_FILE_SECTION_POINTER *Section
+ )
+/*++
+
+Routine Description:
+
+ Find a section in a file by type and instance. An instance of 1 is the first
+ instance. The function will return NULL if a matching section cannot be found.
+ GUID-defined sections, if special processing is not needed, are handled in a
+ depth-first manner.
+
+Arguments:
+
+ File The file to search.
+ SectionType Type of file to search for.
+ Instance Instace of the section to return.
+ Section Return pointer. In the case of an error, contents are undefined.
+
+Returns:
+
+ EFI_SUCCESS The function completed successfully.
+ EFI_ABORTED An error was encountered.
+ EFI_INVALID_PARAMETER One of the parameters was NULL.
+ EFI_NOT_FOUND No found.
+--*/
+{
+ EFI_FILE_SECTION_POINTER CurrentSection;
+ EFI_STATUS Status;
+ UINTN SectionCount;
+
+ //
+ // Verify input parameters
+ //
+ if (File == NULL || Instance == 0) {
+ return EFI_INVALID_PARAMETER;
+ }
+ //
+ // Verify FFS header
+ //
+ Status = VerifyFfsFile (File);
+ if (EFI_ERROR (Status)) {
+ Error (NULL, 0, 0006, "invalid FFS file", NULL);
+ return EFI_ABORTED;
+ }
+ //
+ // Initialize the number of matching sections found.
+ //
+ SectionCount = 0;
+
+ //
+ // Get the first section
+ //
+ CurrentSection.CommonHeader = (EFI_COMMON_SECTION_HEADER *) ((UINTN) File + sizeof (EFI_FFS_FILE_HEADER));
+
+ //
+ // Depth-first manner to find section file.
+ //
+ Status = SearchSectionByType (
+ CurrentSection,
+ (UINT8 *) ((UINTN) File + GetLength (File->Size)),
+ SectionType,
+ &SectionCount,
+ Instance,
+ Section
+ );
+
+ if (!EFI_ERROR (Status)) {
+ return EFI_SUCCESS;
+ } else {
+ //
+ // Section not found
+ //
+ (*Section).Code16Section = NULL;
+ return EFI_NOT_FOUND;
+ }
+}
+//
+// will not parse compressed sections
+//
+EFI_STATUS
+VerifyFv (
+ IN EFI_FIRMWARE_VOLUME_HEADER *FvHeader
+ )
+/*++
+
+Routine Description:
+
+ Verify the current pointer points to a valid FV header.
+
+Arguments:
+
+ FvHeader Pointer to an alleged FV file.
+
+Returns:
+
+ EFI_SUCCESS The FV header is valid.
+ EFI_VOLUME_CORRUPTED The FV header is not valid.
+ EFI_INVALID_PARAMETER A required parameter was NULL.
+ EFI_ABORTED Operation aborted.
+
+--*/
+{
+ UINT16 Checksum;
+
+ //
+ // Verify input parameters
+ //
+ if (FvHeader == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (FvHeader->Signature != EFI_FVH_SIGNATURE) {
+ Error (NULL, 0, 0006, "invalid FV header signature", NULL);
+ return EFI_VOLUME_CORRUPTED;
+ }
+ //
+ // Verify header checksum
+ //
+ Checksum = CalculateSum16 ((UINT16 *) FvHeader, FvHeader->HeaderLength / sizeof (UINT16));
+
+ if (Checksum != 0) {
+ Error (NULL, 0, 0006, "invalid FV header checksum", NULL);
+ return EFI_ABORTED;
+ }
+
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS
+VerifyFfsFile (
+ IN EFI_FFS_FILE_HEADER *FfsHeader
+ )
+/*++
+
+Routine Description:
+
+ Verify the current pointer points to a FFS file header.
+
+Arguments:
+
+ FfsHeader Pointer to an alleged FFS file.
+
+Returns:
+
+ EFI_SUCCESS The Ffs header is valid.
+ EFI_NOT_FOUND This "file" is the beginning of free space.
+ EFI_VOLUME_CORRUPTED The Ffs header is not valid.
+ EFI_ABORTED The erase polarity is not known.
+
+--*/
+{
+ BOOLEAN ErasePolarity;
+ EFI_STATUS Status;
+ EFI_FFS_FILE_HEADER BlankHeader;
+ UINT8 Checksum;
+ UINT32 FileLength;
+ UINT8 SavedChecksum;
+ UINT8 SavedState;
+ UINT8 FileGuidString[80];
+ //
+ // Verify library has been initialized.
+ //
+ if (mFvHeader == NULL || mFvLength == 0) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify FV header
+ //
+ Status = VerifyFv (mFvHeader);
+ if (EFI_ERROR (Status)) {
+ return EFI_ABORTED;
+ }
+ //
+ // Get the erase polarity.
+ //
+ Status = GetErasePolarity (&ErasePolarity);
+ if (EFI_ERROR (Status)) {
+ return EFI_ABORTED;
+ }
+ //
+ // Check if we have free space
+ //
+ if (ErasePolarity) {
+ memset (&BlankHeader, -1, sizeof (EFI_FFS_FILE_HEADER));
+ } else {
+ memset (&BlankHeader, 0, sizeof (EFI_FFS_FILE_HEADER));
+ }
+
+ if (memcmp (&BlankHeader, FfsHeader, sizeof (EFI_FFS_FILE_HEADER)) == 0) {
+ return EFI_NOT_FOUND;
+ }
+ //
+ // Convert the GUID to a string so we can at least report which file
+ // if we find an error.
+ //
+ PrintGuidToBuffer (&FfsHeader->Name, FileGuidString, sizeof (FileGuidString), TRUE);
+ //
+ // Verify file header checksum
+ //
+ SavedState = FfsHeader->State;
+ FfsHeader->State = 0;
+ SavedChecksum = FfsHeader->IntegrityCheck.Checksum.File;
+ FfsHeader->IntegrityCheck.Checksum.File = 0;
+ Checksum = CalculateSum8 ((UINT8 *) FfsHeader, sizeof (EFI_FFS_FILE_HEADER));
+ FfsHeader->State = SavedState;
+ FfsHeader->IntegrityCheck.Checksum.File = SavedChecksum;
+ if (Checksum != 0) {
+ Error (NULL, 0, 0006, "invalid FFS file header checksum", "Ffs file with Guid %s", FileGuidString);
+ return EFI_ABORTED;
+ }
+ //
+ // Verify file checksum
+ //
+ if (FfsHeader->Attributes & FFS_ATTRIB_CHECKSUM) {
+ //
+ // Verify file data checksum
+ //
+ FileLength = GetLength (FfsHeader->Size);
+ Checksum = CalculateSum8 ((UINT8 *) (FfsHeader + 1), FileLength - sizeof (EFI_FFS_FILE_HEADER));
+ Checksum = Checksum + FfsHeader->IntegrityCheck.Checksum.File;
+ if (Checksum != 0) {
+ Error (NULL, 0, 0006, "invalid FFS file checksum", "Ffs file with Guid %s", FileGuidString);
+ return EFI_ABORTED;
+ }
+ } else {
+ //
+ // File does not have a checksum
+ // Verify contents are 0xAA as spec'd
+ //
+ if (FfsHeader->IntegrityCheck.Checksum.File != FFS_FIXED_CHECKSUM) {
+ Error (NULL, 0, 0006, "invalid fixed FFS file header checksum", "Ffs file with Guid %s", FileGuidString);
+ return EFI_ABORTED;
+ }
+ }
+
+ return EFI_SUCCESS;
+}
+
+UINT32
+GetLength (
+ UINT8 *ThreeByteLength
+ )
+/*++
+
+Routine Description:
+
+ Converts a three byte length value into a UINT32.
+
+Arguments:
+
+ ThreeByteLength Pointer to the first of the 3 byte length.
+
+Returns:
+
+ UINT32 Size of the section
+
+--*/
+{
+ UINT32 Length;
+
+ if (ThreeByteLength == NULL) {
+ return 0;
+ }
+
+ Length = *((UINT32 *) ThreeByteLength);
+ Length = Length & 0x00FFFFFF;
+
+ return Length;
+}
+
+EFI_STATUS
+GetErasePolarity (
+ OUT BOOLEAN *ErasePolarity
+ )
+/*++
+
+Routine Description:
+
+ This function returns with the FV erase polarity. If the erase polarity
+ for a bit is 1, the function return TRUE.
+
+Arguments:
+
+ ErasePolarity A pointer to the erase polarity.
+
+Returns:
+
+ EFI_SUCCESS The function completed successfully.
+ EFI_INVALID_PARAMETER One of the input parameters was invalid.
+ EFI_ABORTED Operation aborted.
+
+--*/
+{
+ EFI_STATUS Status;
+
+ //
+ // Verify library has been initialized.
+ //
+ if (mFvHeader == NULL || mFvLength == 0) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify FV header
+ //
+ Status = VerifyFv (mFvHeader);
+ if (EFI_ERROR (Status)) {
+ return EFI_ABORTED;
+ }
+ //
+ // Verify input parameters.
+ //
+ if (ErasePolarity == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (mFvHeader->Attributes & EFI_FVB2_ERASE_POLARITY) {
+ *ErasePolarity = TRUE;
+ } else {
+ *ErasePolarity = FALSE;
+ }
+
+ return EFI_SUCCESS;
+}
+
+UINT8
+GetFileState (
+ IN BOOLEAN ErasePolarity,
+ IN EFI_FFS_FILE_HEADER *FfsHeader
+ )
+/*++
+
+Routine Description:
+
+ This function returns a the highest state bit in the FFS that is set.
+ It in no way validate the FFS file.
+
+Arguments:
+
+ ErasePolarity The erase polarity for the file state bits.
+ FfsHeader Pointer to a FFS file.
+
+Returns:
+
+ UINT8 The hightest set state of the file.
+
+--*/
+{
+ UINT8 FileState;
+ UINT8 HighestBit;
+
+ FileState = FfsHeader->State;
+
+ if (ErasePolarity) {
+ FileState = (UINT8)~FileState;
+ }
+
+ HighestBit = 0x80;
+ while (HighestBit != 0 && (HighestBit & FileState) == 0) {
+ HighestBit >>= 1;
+ }
+
+ return HighestBit;
+}
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