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BaseTools/GenFv: optimize away redundant padding 

To prevent double padding of XIP modules leading to excessive
waste of FV space, try to adjust existing padding rather than
adding more.

Instead of adding a pad file to the FV to line up an FFS file that
itself may contain padding to line up the payload, try to find a
dedicated padding section inside the FFS, and reduce its size to
place all subsequent aligned FFS section at their respective minimum
alignments.

When using 4 KB section alignment (which is required on AARCH64 in
some cases), this will save 4 KB for each XIP module.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Yingke Liu <yingke.d.liu@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18080 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Ard Biesheuvel 2015-07-27 13:50:30 +00:00 committed by abiesheuvel
parent 46d0f3f871
commit 47746688e1
1 changed files with 161 additions and 8 deletions
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169
BaseTools/Source/C/GenFv/GenFvInternalLib.c
View File

@ -31,6 +31,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#endif
#include <assert.h>
#include <Guid/FfsSectionAlignmentPadding.h>
#include "GenFvInternalLib.h"
#include "FvLib.h"
#include "PeCoffLib.h"
@ -39,10 +41,11 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
BOOLEAN mArm = FALSE;
STATIC UINT32 MaxFfsAlignment = 0;
EFI_GUID mEfiFirmwareVolumeTopFileGuid = EFI_FFS_VOLUME_TOP_FILE_GUID;
EFI_GUID mEfiFirmwareVolumeTopFileGuid = EFI_FFS_VOLUME_TOP_FILE_GUID;
EFI_GUID mFileGuidArray [MAX_NUMBER_OF_FILES_IN_FV];
EFI_GUID mZeroGuid = {0x0, 0x0, 0x0, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}};
EFI_GUID mDefaultCapsuleGuid = {0x3B6686BD, 0x0D76, 0x4030, { 0xB7, 0x0E, 0xB5, 0x51, 0x9E, 0x2F, 0xC5, 0xA0 }};
EFI_GUID mZeroGuid = {0x0, 0x0, 0x0, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}};
EFI_GUID mDefaultCapsuleGuid = {0x3B6686BD, 0x0D76, 0x4030, { 0xB7, 0x0E, 0xB5, 0x51, 0x9E, 0x2F, 0xC5, 0xA0 }};
EFI_GUID mEfiFfsSectionAlignmentPaddingGuid = EFI_FFS_SECTION_ALIGNMENT_PADDING_GUID;
CHAR8 *mFvbAttributeName[] = {
EFI_FVB2_READ_DISABLED_CAP_STRING,
@ -934,6 +937,153 @@ Returns:
return EFI_SUCCESS;
}
STATIC
BOOLEAN
AdjustInternalFfsPadding (
IN OUT EFI_FFS_FILE_HEADER *FfsFile,
IN OUT MEMORY_FILE *FvImage,
IN UINTN Alignment,
IN OUT UINTN *FileSize
)
/*++
Routine Description:
This function looks for a dedicated alignment padding section in the FFS, and
shrinks it to the size required to line up subsequent sections correctly.
Arguments:
FfsFile A pointer to Ffs file image.
FvImage The memory image of the FV to adjust it to.
Alignment Current file alignment
FileSize Reference to a variable holding the size of the FFS file
Returns:
TRUE Padding section was found and updated successfully
FALSE Otherwise
--*/
{
EFI_FILE_SECTION_POINTER PadSection;
UINT8 *Remainder;
EFI_STATUS Status;
UINT32 FfsHeaderLength;
UINT32 FfsFileLength;
UINT32 PadSize;
UINTN Misalignment;
EFI_FFS_INTEGRITY_CHECK *IntegrityCheck;
//
// Figure out the misalignment: all FFS sections are aligned relative to the
// start of the FFS payload, so use that as the base of the misalignment
// computation.
//
FfsHeaderLength = GetFfsHeaderLength(FfsFile);
Misalignment = (UINTN) FvImage->CurrentFilePointer -
(UINTN) FvImage->FileImage + FfsHeaderLength;
Misalignment &= Alignment - 1;
if (Misalignment == 0) {
// Nothing to do, return success
return TRUE;
}
//
// We only apply this optimization to FFS files with the FIXED attribute set,
// since the FFS will not be loadable at arbitrary offsets anymore after
// we adjust the size of the padding section.
//
if ((FfsFile->Attributes & FFS_ATTRIB_FIXED) == 0) {
return FALSE;
}
//
// Look for a dedicated padding section that we can adjust to compensate
// for the misalignment. If such a padding section exists, it precedes all
// sections with alignment requirements, and so the adjustment will correct
// all of them.
//
Status = GetSectionByType (FfsFile, EFI_SECTION_FREEFORM_SUBTYPE_GUID, 1,
&PadSection);
if (EFI_ERROR (Status) ||
CompareGuid (&PadSection.FreeformSubtypeSection->SubTypeGuid,
&mEfiFfsSectionAlignmentPaddingGuid) != 0) {
return FALSE;
}
//
// Find out if the size of the padding section is sufficient to compensate
// for the misalignment.
//
PadSize = GetSectionFileLength (PadSection.CommonHeader);
if (Misalignment > PadSize - sizeof (EFI_FREEFORM_SUBTYPE_GUID_SECTION)) {
return FALSE;
}
//
// Move the remainder of the FFS file towards the front, and adjust the
// file size output parameter.
//
Remainder = (UINT8 *) PadSection.CommonHeader + PadSize;
memmove (Remainder - Misalignment, Remainder,
*FileSize - (UINTN) (Remainder - (UINTN) FfsFile));
*FileSize -= Misalignment;
//
// Update the padding section's length with the new values. Note that the
// padding is always < 64 KB, so we can ignore EFI_COMMON_SECTION_HEADER2
// ExtendedSize.
//
PadSize -= Misalignment;
PadSection.CommonHeader->Size[0] = (UINT8) (PadSize & 0xff);
PadSection.CommonHeader->Size[1] = (UINT8) ((PadSize & 0xff00) >> 8);
PadSection.CommonHeader->Size[2] = (UINT8) ((PadSize & 0xff0000) >> 16);
//
// Update the FFS header with the new overall length
//
FfsFileLength = GetFfsFileLength (FfsFile) - Misalignment;
if (FfsHeaderLength > sizeof(EFI_FFS_FILE_HEADER)) {
((EFI_FFS_FILE_HEADER2 *)FfsFile)->ExtendedSize = FfsFileLength;
} else {
FfsFile->Size[0] = (UINT8) (FfsFileLength & 0x000000FF);
FfsFile->Size[1] = (UINT8) ((FfsFileLength & 0x0000FF00) >> 8);
FfsFile->Size[2] = (UINT8) ((FfsFileLength & 0x00FF0000) >> 16);
}
//
// Clear the alignment bits: these have become meaningless now that we have
// adjusted the padding section.
//
FfsFile->Attributes &= ~FFS_ATTRIB_DATA_ALIGNMENT;
//
// Recalculate the FFS header checksum. Instead of setting Header and State
// both to zero, set Header to (UINT8)(-State) so State preserves its original
// value
//
IntegrityCheck = &FfsFile->IntegrityCheck;
IntegrityCheck->Checksum.Header = (UINT8) (0x100 - FfsFile->State);
IntegrityCheck->Checksum.File = 0;
IntegrityCheck->Checksum.Header = CalculateChecksum8 (
(UINT8 *) FfsFile, FfsHeaderLength);
if (FfsFile->Attributes & FFS_ATTRIB_CHECKSUM) {
//
// Ffs header checksum = zero, so only need to calculate ffs body.
//
IntegrityCheck->Checksum.File = CalculateChecksum8 (
(UINT8 *) FfsFile + FfsHeaderLength,
FfsFileLength - FfsHeaderLength);
} else {
IntegrityCheck->Checksum.File = FFS_FIXED_CHECKSUM;
}
return TRUE;
}
EFI_STATUS
AddFile (
IN OUT MEMORY_FILE *FvImage,
@ -1140,11 +1290,14 @@ Returns:
//
// Add pad file if necessary
//
Status = AddPadFile (FvImage, 1 << CurrentFileAlignment, *VtfFileImage, NULL, FileSize);
if (EFI_ERROR (Status)) {
Error (NULL, 0, 4002, "Resource", "FV space is full, could not add pad file for data alignment property.");
free (FileBuffer);
return EFI_ABORTED;
if (!AdjustInternalFfsPadding ((EFI_FFS_FILE_HEADER *) FileBuffer, FvImage,
1 << CurrentFileAlignment, &FileSize)) {
Status = AddPadFile (FvImage, 1 << CurrentFileAlignment, *VtfFileImage, NULL, FileSize);
if (EFI_ERROR (Status)) {
Error (NULL, 0, 4002, "Resource", "FV space is full, could not add pad file for data alignment property.");
free (FileBuffer);
return EFI_ABORTED;
}
}
//
// Add file