diff options
Diffstat (limited to 'EdkCompatibilityPkg/Sample/Tools/Source/Common/FvLib.c')
| -rw-r--r-- | EdkCompatibilityPkg/Sample/Tools/Source/Common/FvLib.c | 873 |
1 files changed, 0 insertions, 873 deletions
diff --git a/EdkCompatibilityPkg/Sample/Tools/Source/Common/FvLib.c b/EdkCompatibilityPkg/Sample/Tools/Source/Common/FvLib.c deleted file mode 100644 index f133d358d5..0000000000 --- a/EdkCompatibilityPkg/Sample/Tools/Source/Common/FvLib.c +++ /dev/null @@ -1,873 +0,0 @@ -/*++
-
-Copyright (c) 2004 - 2010, 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;
- 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 + GetLength (CurrentFile->Size) + 0x07) & (-1 << 3));
-
- //
- // 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;
-
- //
- // 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;
- }
- //
- // 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, 0, "error parsing the FV", NULL);
- 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, 0, "error parsing the FV", NULL);
- 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, 0, "error parsing FV", NULL);
- 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, 0, "error parsing the FV", NULL);
- 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, 0, "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));
-
- 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, 0, "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, 0, "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;
- UINT32 OccupiedFileLength;
- UINT8 SavedChecksum;
- UINT8 SavedState;
- UINT8 FileGuidString[80];
- UINT32 TailSize;
-#if (PI_SPECIFICATION_VERSION < 0x00010000)
- EFI_FFS_FILE_TAIL *Tail;
-#endif
-
- //
- // 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);
- if (FfsHeader->Attributes & FFS_ATTRIB_TAIL_PRESENT) {
- TailSize = sizeof (EFI_FFS_FILE_TAIL);
- } else {
- TailSize = 0;
- }
- //
- // 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, 0, FileGuidString, "invalid FFS file header checksum");
- return EFI_ABORTED;
- }
- //
- // Verify file checksum
- //
- if (FfsHeader->Attributes & FFS_ATTRIB_CHECKSUM) {
- //
- // Verify file data checksum
- //
- FileLength = GetLength (FfsHeader->Size);
- OccupiedFileLength = (FileLength + 0x07) & (-1 << 3);
-#if (PI_SPECIFICATION_VERSION < 0x00010000)
- Checksum = CalculateSum8 ((UINT8 *) FfsHeader, FileLength - TailSize);
- Checksum = (UINT8) (Checksum - FfsHeader->State);
-#else
- Checksum = CalculateSum8 ((UINT8 *) ((UINTN)FfsHeader + sizeof (EFI_FFS_FILE_HEADER)), FileLength - TailSize - sizeof (EFI_FFS_FILE_HEADER));
- Checksum = Checksum + (UINT8)FfsHeader->IntegrityCheck.Checksum.File;
-#endif
- if (Checksum != 0) {
- Error (NULL, 0, 0, FileGuidString, "invalid FFS file checksum");
- return EFI_ABORTED;
- }
- } else {
- //
- // File does not have a checksum
- // Verify contents are 0x5A(Framework) and 0xAA(PI 1.0) as spec'd
- //
- if (FfsHeader->IntegrityCheck.Checksum.File != FFS_FIXED_CHECKSUM) {
- Error (NULL, 0, 0, FileGuidString, "invalid fixed file checksum");
- return EFI_ABORTED;
- }
- }
-#if (PI_SPECIFICATION_VERSION < 0x00010000)
- //
- // Check if the tail is present and verify it if it is.
- //
- if (FfsHeader->Attributes & FFS_ATTRIB_TAIL_PRESENT) {
- //
- // Verify tail is complement of integrity check field in the header.
- //
- Tail = (EFI_FFS_FILE_TAIL *) ((UINTN) FfsHeader + GetLength (FfsHeader->Size) - sizeof (EFI_FFS_FILE_TAIL));
- if (FfsHeader->IntegrityCheck.TailReference != (EFI_FFS_FILE_TAIL)~(*Tail)) {
- Error (NULL, 0, 0, FileGuidString, "invalid FFS file tail");
- return EFI_ABORTED;
- }
- }
-#endif
- 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_FVB_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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