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.biesheu...@linaro.org>
---
BaseTools/Source/C/GenFv/GenFvInternalLib.c | 169 +++++++++++++++++++-
1 file changed, 161 insertions(+), 8 deletions(-)
diff --git a/BaseTools/Source/C/GenFv/GenFvInternalLib.c
b/BaseTools/Source/C/GenFv/GenFvInternalLib.c
index 005098508b26..6d2d5d1f8c67 100644
--- a/BaseTools/Source/C/GenFv/GenFvInternalLib.c
+++ b/BaseTools/Source/C/GenFv/GenFvInternalLib.c
@@ -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
--
1.9.1
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