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/*++
Copyright (c) 2004, Intel Corporation
All rights reserved. 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:
Ffs.c
Abstract:
FFS file access utilities.
--*/
#include "FwVolDriver.h"
#define PHYSICAL_ADDRESS_TO_POINTER(Address) ((VOID *)((UINTN)(Address)))
EFI_FFS_FILE_STATE
GetFileState (
IN UINT8 ErasePolarity,
IN EFI_FFS_FILE_HEADER *FfsHeader
)
/*++
Routine Description:
Get the FFS file state by checking the highest bit set in the header's state field
Arguments:
ErasePolarity - Erase polarity attribute of the firmware volume
FfsHeader - Points to the FFS file header
Returns:
FFS File state
--*/
{
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;
}
BOOLEAN
IsBufferErased (
IN UINT8 ErasePolarity,
IN VOID *InBuffer,
IN UINTN BufferSize
)
/*++
Routine Description:
Check if a block of buffer is erased
Arguments:
ErasePolarity - Erase polarity attribute of the firmware volume
InBuffer - The buffer to be checked
BufferSize - Size of the buffer in bytes
Returns:
TRUE - The block of buffer is erased
FALSE - The block of buffer is not erased
--*/
{
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;
}
BOOLEAN
VerifyFvHeaderChecksum (
IN EFI_FIRMWARE_VOLUME_HEADER *FvHeader
)
/*++
Routine Description:
Verify checksum of the firmware volume header
Arguments:
FvHeader - Points to the firmware volume header to be checked
Returns:
TRUE - Checksum verification passed
FALSE - Checksum verification failed
--*/
{
UINT32 Index;
UINT32 HeaderLength;
UINT16 Checksum;
UINT16 *ptr;
HeaderLength = FvHeader->HeaderLength;
ptr = (UINT16 *)FvHeader;
Checksum = 0;
for (Index = 0; Index < HeaderLength / sizeof (UINT16); Index++) {
Checksum = (UINT16)(Checksum + ptr[Index]);
}
if (Checksum == 0) {
return TRUE;
} else {
return FALSE;
}
}
BOOLEAN
VerifyHeaderChecksum (
IN EFI_FFS_FILE_HEADER *FfsHeader
)
/*++
Routine Description:
Verify checksum of the FFS file header
Arguments:
FfsHeader - Points to the FFS file header to be checked
Returns:
TRUE - Checksum verification passed
FALSE - Checksum verification failed
--*/
{
UINT32 Index;
UINT8 *ptr;
UINT8 HeaderChecksum;
ptr = (UINT8 *)FfsHeader;
HeaderChecksum = 0;
for (Index = 0; Index < sizeof(EFI_FFS_FILE_HEADER); Index++) {
HeaderChecksum = (UINT8)(HeaderChecksum + ptr[Index]);
}
HeaderChecksum = HeaderChecksum - FfsHeader->State - FfsHeader->IntegrityCheck.Checksum.File;
if (HeaderChecksum == 0) {
return TRUE;
} else {
return FALSE;
}
}
BOOLEAN
IsValidFfsHeader (
IN UINT8 ErasePolarity,
IN EFI_FFS_FILE_HEADER *FfsHeader,
OUT EFI_FFS_FILE_STATE *FileState
)
/*++
Routine Description:
Check if it's a valid FFS file header
Arguments:
ErasePolarity - Erase polarity attribute of the firmware volume
FfsHeader - Points to the FFS file header to be checked
FileState - FFS file state to be returned
Returns:
TRUE - Valid FFS file header
FALSE - Invalid FFS file header
--*/
{
*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;
}
}
BOOLEAN
IsValidFfsFile (
IN UINT8 ErasePolarity,
IN EFI_FFS_FILE_HEADER *FfsHeader
)
/*++
Routine Description:
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.
Arguments:
ErasePolarity - Erase polarity attribute of the firmware volume
FfsHeader - Points to the FFS file to be checked
Returns:
TRUE - Valid FFS file
FALSE - Invalid FFS file
--*/
{
EFI_FFS_FILE_STATE FileState;
FileState = GetFileState (ErasePolarity, FfsHeader);
switch (FileState) {
case EFI_FILE_DELETED:
case EFI_FILE_DATA_VALID:
case EFI_FILE_MARKED_FOR_UPDATE:
//
// Some other vliadation like file content checksum might be done here.
// For performance issue, Tiano only do FileState check.
//
return TRUE;
default:
return FALSE;
}
}
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