diff options
Diffstat (limited to 'roms/edk2/MdeModulePkg/Core/Dxe/FwVol/Ffs.c')
| -rw-r--r-- | roms/edk2/MdeModulePkg/Core/Dxe/FwVol/Ffs.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/roms/edk2/MdeModulePkg/Core/Dxe/FwVol/Ffs.c b/roms/edk2/MdeModulePkg/Core/Dxe/FwVol/Ffs.c new file mode 100644 index 000000000..199c7f821 --- /dev/null +++ b/roms/edk2/MdeModulePkg/Core/Dxe/FwVol/Ffs.c @@ -0,0 +1,227 @@ +/** @file
+ FFS file access utilities.
+
+Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include "DxeMain.h"
+#include "FwVolDriver.h"
+
+
+/**
+ Get the FFS file state by checking the highest bit set in the header's state field.
+
+ @param ErasePolarity Erase polarity attribute of the firmware volume
+ @param FfsHeader Points to the FFS file header
+
+ @return FFS File state
+
+**/
+EFI_FFS_FILE_STATE
+GetFileState (
+ IN UINT8 ErasePolarity,
+ IN EFI_FFS_FILE_HEADER *FfsHeader
+ )
+{
+ EFI_FFS_FILE_STATE FileState;
+ UINT8 HighestBit;
+
+ FileState = FfsHeader->State;
+
+ if (ErasePolarity != 0) {
+ FileState = (EFI_FFS_FILE_STATE)~FileState;
+ }
+
+ HighestBit = 0x80;
+ while (HighestBit != 0 && ((HighestBit & FileState) == 0)) {
+ HighestBit >>= 1;
+ }
+
+ return (EFI_FFS_FILE_STATE) HighestBit;
+}
+
+
+
+/**
+ Check if a block of buffer is erased.
+
+ @param ErasePolarity Erase polarity attribute of the firmware volume
+ @param InBuffer The buffer to be checked
+ @param BufferSize Size of the buffer in bytes
+
+ @retval TRUE The block of buffer is erased
+ @retval FALSE The block of buffer is not erased
+
+**/
+BOOLEAN
+IsBufferErased (
+ IN UINT8 ErasePolarity,
+ IN VOID *InBuffer,
+ IN UINTN BufferSize
+ )
+{
+ UINTN Count;
+ UINT8 EraseByte;
+ UINT8 *Buffer;
+
+ if(ErasePolarity == 1) {
+ EraseByte = 0xFF;
+ } else {
+ EraseByte = 0;
+ }
+
+ Buffer = InBuffer;
+ for (Count = 0; Count < BufferSize; Count++) {
+ if (Buffer[Count] != EraseByte) {
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
+
+
+/**
+ Verify checksum of the firmware volume header.
+
+ @param FvHeader Points to the firmware volume header to be checked
+
+ @retval TRUE Checksum verification passed
+ @retval FALSE Checksum verification failed
+
+**/
+BOOLEAN
+VerifyFvHeaderChecksum (
+ IN EFI_FIRMWARE_VOLUME_HEADER *FvHeader
+ )
+{
+ UINT16 Checksum;
+
+ Checksum = CalculateSum16 ((UINT16 *) FvHeader, FvHeader->HeaderLength);
+
+ if (Checksum == 0) {
+ return TRUE;
+ } else {
+ return FALSE;
+ }
+}
+
+
+/**
+ Verify checksum of the FFS file header.
+
+ @param FfsHeader Points to the FFS file header to be checked
+
+ @retval TRUE Checksum verification passed
+ @retval FALSE Checksum verification failed
+
+**/
+BOOLEAN
+VerifyHeaderChecksum (
+ IN EFI_FFS_FILE_HEADER *FfsHeader
+ )
+{
+ UINT8 HeaderChecksum;
+
+ if (IS_FFS_FILE2 (FfsHeader)) {
+ HeaderChecksum = CalculateSum8 ((UINT8 *) FfsHeader, sizeof (EFI_FFS_FILE_HEADER2));
+ } else {
+ HeaderChecksum = CalculateSum8 ((UINT8 *) FfsHeader, sizeof (EFI_FFS_FILE_HEADER));
+ }
+ HeaderChecksum = (UINT8) (HeaderChecksum - FfsHeader->State - FfsHeader->IntegrityCheck.Checksum.File);
+
+ if (HeaderChecksum == 0) {
+ return TRUE;
+ } else {
+ return FALSE;
+ }
+}
+
+
+
+/**
+ Check if it's a valid FFS file header.
+
+ @param ErasePolarity Erase polarity attribute of the firmware volume
+ @param FfsHeader Points to the FFS file header to be checked
+ @param FileState FFS file state to be returned
+
+ @retval TRUE Valid FFS file header
+ @retval FALSE Invalid FFS file header
+
+**/
+BOOLEAN
+IsValidFfsHeader (
+ IN UINT8 ErasePolarity,
+ IN EFI_FFS_FILE_HEADER *FfsHeader,
+ OUT EFI_FFS_FILE_STATE *FileState
+ )
+{
+ *FileState = GetFileState (ErasePolarity, FfsHeader);
+
+ switch (*FileState) {
+ case EFI_FILE_HEADER_VALID:
+ case EFI_FILE_DATA_VALID:
+ case EFI_FILE_MARKED_FOR_UPDATE:
+ case EFI_FILE_DELETED:
+ //
+ // Here we need to verify header checksum
+ //
+ return VerifyHeaderChecksum (FfsHeader);
+
+ case EFI_FILE_HEADER_CONSTRUCTION:
+ case EFI_FILE_HEADER_INVALID:
+ default:
+ return FALSE;
+ }
+}
+
+
+/**
+ Check if it's a valid FFS file.
+ Here we are sure that it has a valid FFS file header since we must call IsValidFfsHeader() first.
+
+ @param ErasePolarity Erase polarity attribute of the firmware volume
+ @param FfsHeader Points to the FFS file to be checked
+
+ @retval TRUE Valid FFS file
+ @retval FALSE Invalid FFS file
+
+**/
+BOOLEAN
+IsValidFfsFile (
+ IN UINT8 ErasePolarity,
+ IN EFI_FFS_FILE_HEADER *FfsHeader
+ )
+{
+ EFI_FFS_FILE_STATE FileState;
+ UINT8 DataCheckSum;
+
+ FileState = GetFileState (ErasePolarity, FfsHeader);
+ switch (FileState) {
+
+ case EFI_FILE_DELETED:
+ case EFI_FILE_DATA_VALID:
+ case EFI_FILE_MARKED_FOR_UPDATE:
+ DataCheckSum = FFS_FIXED_CHECKSUM;
+ if ((FfsHeader->Attributes & FFS_ATTRIB_CHECKSUM) == FFS_ATTRIB_CHECKSUM) {
+ if (IS_FFS_FILE2 (FfsHeader)) {
+ DataCheckSum = CalculateCheckSum8 ((CONST UINT8 *) FfsHeader + sizeof (EFI_FFS_FILE_HEADER2), FFS_FILE2_SIZE (FfsHeader) - sizeof(EFI_FFS_FILE_HEADER2));
+ } else {
+ DataCheckSum = CalculateCheckSum8 ((CONST UINT8 *) FfsHeader + sizeof (EFI_FFS_FILE_HEADER), FFS_FILE_SIZE (FfsHeader) - sizeof(EFI_FFS_FILE_HEADER));
+ }
+ }
+ if (FfsHeader->IntegrityCheck.Checksum.File == DataCheckSum) {
+ return TRUE;
+ }
+
+ default:
+ return FALSE;
+ }
+}
+
+
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