audk/BaseTools/Source/C/GenFw/Elf64Convert.c

/** @file
Elf64 convert solution

Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>
Portions copyright (c) 2013-2014, ARM Ltd. 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.

**/

#include "WinNtInclude.h"

#ifndef __GNUC__
#include <windows.h>
#include <io.h>
#endif
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <ctype.h>

#include <Common/UefiBaseTypes.h>
#include <IndustryStandard/PeImage.h>

#include "PeCoffLib.h"
#include "EfiUtilityMsgs.h"

#include "GenFw.h"
#include "ElfConvert.h"
#include "Elf64Convert.h"

STATIC
VOID
ScanSections64 (
  VOID
  );

STATIC
BOOLEAN
WriteSections64 (
  SECTION_FILTER_TYPES  FilterType
  );

STATIC
VOID
WriteRelocations64 (
  VOID
  );

STATIC
VOID
WriteDebug64 (
  VOID
  );

STATIC
VOID
SetImageSize64 (
  VOID
  );

STATIC
VOID
CleanUp64 (
  VOID
  );

//
// Rename ELF32 strucutres to common names to help when porting to ELF64.
//
typedef Elf64_Shdr Elf_Shdr;
typedef Elf64_Ehdr Elf_Ehdr;
typedef Elf64_Rel Elf_Rel;
typedef Elf64_Rela Elf_Rela;
typedef Elf64_Sym Elf_Sym;
typedef Elf64_Phdr Elf_Phdr;
typedef Elf64_Dyn Elf_Dyn;
#define ELFCLASS ELFCLASS64
#define ELF_R_TYPE(r) ELF64_R_TYPE(r)
#define ELF_R_SYM(r) ELF64_R_SYM(r)

//
// Well known ELF structures.
//
STATIC Elf_Ehdr *mEhdr;
STATIC Elf_Shdr *mShdrBase;
STATIC Elf_Phdr *mPhdrBase;

//
// Coff information
//
STATIC UINT32 mCoffAlignment = 0x20;

//
// PE section alignment.
//
STATIC const UINT16 mCoffNbrSections = 4;

//
// ELF sections to offset in Coff file.
//
STATIC UINT32 *mCoffSectionsOffset = NULL;

//
// Offsets in COFF file
//
STATIC UINT32 mNtHdrOffset;
STATIC UINT32 mTextOffset;
STATIC UINT32 mDataOffset;
STATIC UINT32 mHiiRsrcOffset;
STATIC UINT32 mRelocOffset;
STATIC UINT32 mDebugOffset;

//
// Initialization Function
//
BOOLEAN
InitializeElf64 (
  UINT8               *FileBuffer,
  ELF_FUNCTION_TABLE  *ElfFunctions
  )
{
  //
  // Initialize data pointer and structures.
  //
  VerboseMsg ("Set EHDR");
  mEhdr = (Elf_Ehdr*) FileBuffer;

  //
  // Check the ELF64 specific header information.
  //
  VerboseMsg ("Check ELF64 Header Information");
  if (mEhdr->e_ident[EI_CLASS] != ELFCLASS64) {
    Error (NULL, 0, 3000, "Unsupported", "ELF EI_DATA not ELFCLASS64");
    return FALSE;
  }
  if (mEhdr->e_ident[EI_DATA] != ELFDATA2LSB) {
    Error (NULL, 0, 3000, "Unsupported", "ELF EI_DATA not ELFDATA2LSB");
    return FALSE;
  }
  if ((mEhdr->e_type != ET_EXEC) && (mEhdr->e_type != ET_DYN)) {
    Error (NULL, 0, 3000, "Unsupported", "ELF e_type not ET_EXEC or ET_DYN");
    return FALSE;
  }
  if (!((mEhdr->e_machine == EM_X86_64) || (mEhdr->e_machine == EM_AARCH64))) {
    Error (NULL, 0, 3000, "Unsupported", "ELF e_machine not EM_X86_64 or EM_AARCH64");
    return FALSE;
  }
  if (mEhdr->e_version != EV_CURRENT) {
    Error (NULL, 0, 3000, "Unsupported", "ELF e_version (%u) not EV_CURRENT (%d)", (unsigned) mEhdr->e_version, EV_CURRENT);
    return FALSE;
  }

  //
  // Update section header pointers
  //
  VerboseMsg ("Update Header Pointers");
  mShdrBase  = (Elf_Shdr *)((UINT8 *)mEhdr + mEhdr->e_shoff);
  mPhdrBase = (Elf_Phdr *)((UINT8 *)mEhdr + mEhdr->e_phoff);

  //
  // Create COFF Section offset buffer and zero.
  //
  VerboseMsg ("Create COFF Section Offset Buffer");
  mCoffSectionsOffset = (UINT32 *)malloc(mEhdr->e_shnum * sizeof (UINT32));
  if (mCoffSectionsOffset == NULL) {
    Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
    return FALSE;
  }
  memset(mCoffSectionsOffset, 0, mEhdr->e_shnum * sizeof(UINT32));

  //
  // Fill in function pointers.
  //
  VerboseMsg ("Fill in Function Pointers");
  ElfFunctions->ScanSections = ScanSections64;
  ElfFunctions->WriteSections = WriteSections64;
  ElfFunctions->WriteRelocations = WriteRelocations64;
  ElfFunctions->WriteDebug = WriteDebug64;
  ElfFunctions->SetImageSize = SetImageSize64;
  ElfFunctions->CleanUp = CleanUp64;

  return TRUE;
}


//
// Header by Index functions
//
STATIC
Elf_Shdr*
GetShdrByIndex (
  UINT32 Num
  )
{
  if (Num >= mEhdr->e_shnum) {
    Error (NULL, 0, 3000, "Invalid", "GetShdrByIndex: Index %u is too high.", Num);
    exit(EXIT_FAILURE);
  }

  return (Elf_Shdr*)((UINT8*)mShdrBase + Num * mEhdr->e_shentsize);
}

STATIC
UINT32
CoffAlign (
  UINT32 Offset
  )
{
  return (Offset + mCoffAlignment - 1) & ~(mCoffAlignment - 1);
}

STATIC
UINT32
DebugRvaAlign (
  UINT32 Offset
  )
{
  return (Offset + 3) & ~3;
}

//
// filter functions
//
STATIC
BOOLEAN
IsTextShdr (
  Elf_Shdr *Shdr
  )
{
  return (BOOLEAN) ((Shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == SHF_ALLOC);
}

STATIC
BOOLEAN
IsHiiRsrcShdr (
  Elf_Shdr *Shdr
  )
{
  Elf_Shdr *Namedr = GetShdrByIndex(mEhdr->e_shstrndx);

  return (BOOLEAN) (strcmp((CHAR8*)mEhdr + Namedr->sh_offset + Shdr->sh_name, ELF_HII_SECTION_NAME) == 0);
}

STATIC
BOOLEAN
IsDataShdr (
  Elf_Shdr *Shdr
  )
{
  if (IsHiiRsrcShdr(Shdr)) {
    return FALSE;
  }
  return (BOOLEAN) (Shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == (SHF_ALLOC | SHF_WRITE);
}

STATIC
BOOLEAN
IsStrtabShdr (
  Elf_Shdr *Shdr
  )
{
  Elf_Shdr *Namedr = GetShdrByIndex(mEhdr->e_shstrndx);

  return (BOOLEAN) (strcmp((CHAR8*)mEhdr + Namedr->sh_offset + Shdr->sh_name, ELF_STRTAB_SECTION_NAME) == 0);
}

STATIC
Elf_Shdr *
FindStrtabShdr (
  VOID
  )
{
  UINT32 i;
  for (i = 0; i < mEhdr->e_shnum; i++) {
    Elf_Shdr *shdr = GetShdrByIndex(i);
    if (IsStrtabShdr(shdr)) {
      return shdr;
    }
  }
  return NULL;
}

STATIC
const UINT8 *
GetSymName (
  Elf_Sym *Sym
  )
{
  Elf_Shdr *StrtabShdr;
  UINT8    *StrtabContents;
  BOOLEAN  foundEnd;
  UINT32   i;

  if (Sym->st_name == 0) {
    return NULL;
  }

  StrtabShdr = FindStrtabShdr();
  if (StrtabShdr == NULL) {
    return NULL;
  }

  assert(Sym->st_name < StrtabShdr->sh_size);

  StrtabContents = (UINT8*)mEhdr + StrtabShdr->sh_offset;

  foundEnd = FALSE;
  for (i= Sym->st_name; (i < StrtabShdr->sh_size) && !foundEnd; i++) {
    foundEnd = (BOOLEAN)(StrtabContents[i] == 0);
  }
  assert(foundEnd);

  return StrtabContents + Sym->st_name;
}

//
// Elf functions interface implementation
//

STATIC
VOID
ScanSections64 (
  VOID
  )
{
  UINT32                          i;
  EFI_IMAGE_DOS_HEADER            *DosHdr;
  EFI_IMAGE_OPTIONAL_HEADER_UNION *NtHdr;
  UINT32                          CoffEntry;
  UINT32                          SectionCount;
  BOOLEAN                         FoundSection;

  CoffEntry = 0;
  mCoffOffset = 0;

  //
  // Coff file start with a DOS header.
  //
  mCoffOffset = sizeof(EFI_IMAGE_DOS_HEADER) + 0x40;
  mNtHdrOffset = mCoffOffset;
  switch (mEhdr->e_machine) {
  case EM_X86_64:
  case EM_IA_64:
  case EM_AARCH64:
    mCoffOffset += sizeof (EFI_IMAGE_NT_HEADERS64);
  break;
  default:
    VerboseMsg ("%s unknown e_machine type %hu. Assume X64", mInImageName, mEhdr->e_machine);
    mCoffOffset += sizeof (EFI_IMAGE_NT_HEADERS64);
  break;
  }

  mTableOffset = mCoffOffset;
  mCoffOffset += mCoffNbrSections * sizeof(EFI_IMAGE_SECTION_HEADER);

  //
  // Set mCoffAlignment to the maximum alignment of the input sections
  // we care about
  //
  for (i = 0; i < mEhdr->e_shnum; i++) {
    Elf_Shdr *shdr = GetShdrByIndex(i);
    if (shdr->sh_addralign <= mCoffAlignment) {
      continue;
    }
    if (IsTextShdr(shdr) || IsDataShdr(shdr) || IsHiiRsrcShdr(shdr)) {
      mCoffAlignment = (UINT32)shdr->sh_addralign;
    }
  }

  //
  // Move the PE/COFF header right before the first section. This will help us
  // save space when converting to TE.
  //
  if (mCoffAlignment > mCoffOffset) {
    mNtHdrOffset += mCoffAlignment - mCoffOffset;
    mTableOffset += mCoffAlignment - mCoffOffset;
    mCoffOffset = mCoffAlignment;
  }

  //
  // First text sections.
  //
  mCoffOffset = CoffAlign(mCoffOffset);
  mTextOffset = mCoffOffset;
  FoundSection = FALSE;
  SectionCount = 0;
  for (i = 0; i < mEhdr->e_shnum; i++) {
    Elf_Shdr *shdr = GetShdrByIndex(i);
    if (IsTextShdr(shdr)) {
      if ((shdr->sh_addralign != 0) && (shdr->sh_addralign != 1)) {
        // the alignment field is valid
        if ((shdr->sh_addr & (shdr->sh_addralign - 1)) == 0) {
          // if the section address is aligned we must align PE/COFF
          mCoffOffset = (UINT32) ((mCoffOffset + shdr->sh_addralign - 1) & ~(shdr->sh_addralign - 1));
        } else {
          Error (NULL, 0, 3000, "Invalid", "Section address not aligned to its own alignment.");
        }
      }

      /* Relocate entry.  */
      if ((mEhdr->e_entry >= shdr->sh_addr) &&
          (mEhdr->e_entry < shdr->sh_addr + shdr->sh_size)) {
        CoffEntry = (UINT32) (mCoffOffset + mEhdr->e_entry - shdr->sh_addr);
      }

      //
      // Set mTextOffset with the offset of the first '.text' section
      //
      if (!FoundSection) {
        mTextOffset = mCoffOffset;
        FoundSection = TRUE;
      }

      mCoffSectionsOffset[i] = mCoffOffset;
      mCoffOffset += (UINT32) shdr->sh_size;
      SectionCount ++;
    }
  }

  if (!FoundSection) {
    Error (NULL, 0, 3000, "Invalid", "Did not find any '.text' section.");
    assert (FALSE);
  }

  mDebugOffset = DebugRvaAlign(mCoffOffset);
  mCoffOffset = CoffAlign(mCoffOffset);

  if (SectionCount > 1 && mOutImageType == FW_EFI_IMAGE) {
    Warning (NULL, 0, 0, NULL, "Mulitple sections in %s are merged into 1 text section. Source level debug might not work correctly.", mInImageName);
  }

  //
  //  Then data sections.
  //
  mDataOffset = mCoffOffset;
  FoundSection = FALSE;
  SectionCount = 0;
  for (i = 0; i < mEhdr->e_shnum; i++) {
    Elf_Shdr *shdr = GetShdrByIndex(i);
    if (IsDataShdr(shdr)) {
      if ((shdr->sh_addralign != 0) && (shdr->sh_addralign != 1)) {
        // the alignment field is valid
        if ((shdr->sh_addr & (shdr->sh_addralign - 1)) == 0) {
          // if the section address is aligned we must align PE/COFF
          mCoffOffset = (UINT32) ((mCoffOffset + shdr->sh_addralign - 1) & ~(shdr->sh_addralign - 1));
        } else {
          Error (NULL, 0, 3000, "Invalid", "Section address not aligned to its own alignment.");
        }
      }

      //
      // Set mDataOffset with the offset of the first '.data' section
      //
      if (!FoundSection) {
        mDataOffset = mCoffOffset;
        FoundSection = TRUE;
      }
      mCoffSectionsOffset[i] = mCoffOffset;
      mCoffOffset += (UINT32) shdr->sh_size;
      SectionCount ++;
    }
  }

  //
  // Make room for .debug data in .data (or .text if .data is empty) instead of
  // putting it in a section of its own. This is explicitly allowed by the
  // PE/COFF spec, and prevents bloat in the binary when using large values for
  // section alignment.
  //
  if (SectionCount > 0) {
    mDebugOffset = DebugRvaAlign(mCoffOffset);
  }
  mCoffOffset = mDebugOffset + sizeof(EFI_IMAGE_DEBUG_DIRECTORY_ENTRY) +
                sizeof(EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY) +
                strlen(mInImageName) + 1;

  mCoffOffset = CoffAlign(mCoffOffset);
  if (SectionCount == 0) {
    mDataOffset = mCoffOffset;
  }

  if (SectionCount > 1 && mOutImageType == FW_EFI_IMAGE) {
    Warning (NULL, 0, 0, NULL, "Mulitple sections in %s are merged into 1 data section. Source level debug might not work correctly.", mInImageName);
  }

  //
  //  The HII resource sections.
  //
  mHiiRsrcOffset = mCoffOffset;
  for (i = 0; i < mEhdr->e_shnum; i++) {
    Elf_Shdr *shdr = GetShdrByIndex(i);
    if (IsHiiRsrcShdr(shdr)) {
      if ((shdr->sh_addralign != 0) && (shdr->sh_addralign != 1)) {
        // the alignment field is valid
        if ((shdr->sh_addr & (shdr->sh_addralign - 1)) == 0) {
          // if the section address is aligned we must align PE/COFF
          mCoffOffset = (UINT32) ((mCoffOffset + shdr->sh_addralign - 1) & ~(shdr->sh_addralign - 1));
        } else {
          Error (NULL, 0, 3000, "Invalid", "Section address not aligned to its own alignment.");
        }
      }
      if (shdr->sh_size != 0) {
        mHiiRsrcOffset = mCoffOffset;
        mCoffSectionsOffset[i] = mCoffOffset;
        mCoffOffset += (UINT32) shdr->sh_size;
        mCoffOffset = CoffAlign(mCoffOffset);
        SetHiiResourceHeader ((UINT8*) mEhdr + shdr->sh_offset, mHiiRsrcOffset);
      }
      break;
    }
  }

  mRelocOffset = mCoffOffset;

  //
  // Allocate base Coff file.  Will be expanded later for relocations.
  //
  mCoffFile = (UINT8 *)malloc(mCoffOffset);
  if (mCoffFile == NULL) {
    Error (NULL, 0, 4001, "Resource", "memory cannot be allocated!");
  }
  assert (mCoffFile != NULL);
  memset(mCoffFile, 0, mCoffOffset);

  //
  // Fill headers.
  //
  DosHdr = (EFI_IMAGE_DOS_HEADER *)mCoffFile;
  DosHdr->e_magic = EFI_IMAGE_DOS_SIGNATURE;
  DosHdr->e_lfanew = mNtHdrOffset;

  NtHdr = (EFI_IMAGE_OPTIONAL_HEADER_UNION*)(mCoffFile + mNtHdrOffset);

  NtHdr->Pe32Plus.Signature = EFI_IMAGE_NT_SIGNATURE;

  switch (mEhdr->e_machine) {
  case EM_X86_64:
    NtHdr->Pe32Plus.FileHeader.Machine = EFI_IMAGE_MACHINE_X64;
    NtHdr->Pe32Plus.OptionalHeader.Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
    break;
  case EM_IA_64:
    NtHdr->Pe32Plus.FileHeader.Machine = EFI_IMAGE_MACHINE_IPF;
    NtHdr->Pe32Plus.OptionalHeader.Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
    break;
  case EM_AARCH64:
    NtHdr->Pe32Plus.FileHeader.Machine = EFI_IMAGE_MACHINE_AARCH64;
    NtHdr->Pe32Plus.OptionalHeader.Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
    break;
  default:
    VerboseMsg ("%s unknown e_machine type. Assume X64", (UINTN)mEhdr->e_machine);
    NtHdr->Pe32Plus.FileHeader.Machine = EFI_IMAGE_MACHINE_X64;
    NtHdr->Pe32Plus.OptionalHeader.Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
  }

  NtHdr->Pe32Plus.FileHeader.NumberOfSections = mCoffNbrSections;
  NtHdr->Pe32Plus.FileHeader.TimeDateStamp = (UINT32) time(NULL);
  mImageTimeStamp = NtHdr->Pe32Plus.FileHeader.TimeDateStamp;
  NtHdr->Pe32Plus.FileHeader.PointerToSymbolTable = 0;
  NtHdr->Pe32Plus.FileHeader.NumberOfSymbols = 0;
  NtHdr->Pe32Plus.FileHeader.SizeOfOptionalHeader = sizeof(NtHdr->Pe32Plus.OptionalHeader);
  NtHdr->Pe32Plus.FileHeader.Characteristics = EFI_IMAGE_FILE_EXECUTABLE_IMAGE
    | EFI_IMAGE_FILE_LINE_NUMS_STRIPPED
    | EFI_IMAGE_FILE_LOCAL_SYMS_STRIPPED
    | EFI_IMAGE_FILE_LARGE_ADDRESS_AWARE;

  NtHdr->Pe32Plus.OptionalHeader.SizeOfCode = mDataOffset - mTextOffset;
  NtHdr->Pe32Plus.OptionalHeader.SizeOfInitializedData = mRelocOffset - mDataOffset;
  NtHdr->Pe32Plus.OptionalHeader.SizeOfUninitializedData = 0;
  NtHdr->Pe32Plus.OptionalHeader.AddressOfEntryPoint = CoffEntry;

  NtHdr->Pe32Plus.OptionalHeader.BaseOfCode = mTextOffset;

  NtHdr->Pe32Plus.OptionalHeader.ImageBase = 0;
  NtHdr->Pe32Plus.OptionalHeader.SectionAlignment = mCoffAlignment;
  NtHdr->Pe32Plus.OptionalHeader.FileAlignment = mCoffAlignment;
  NtHdr->Pe32Plus.OptionalHeader.SizeOfImage = 0;

  NtHdr->Pe32Plus.OptionalHeader.SizeOfHeaders = mTextOffset;
  NtHdr->Pe32Plus.OptionalHeader.NumberOfRvaAndSizes = EFI_IMAGE_NUMBER_OF_DIRECTORY_ENTRIES;

  //
  // Section headers.
  //
  if ((mDataOffset - mTextOffset) > 0) {
    CreateSectionHeader (".text", mTextOffset, mDataOffset - mTextOffset,
            EFI_IMAGE_SCN_CNT_CODE
            | EFI_IMAGE_SCN_MEM_EXECUTE
            | EFI_IMAGE_SCN_MEM_READ);
  } else {
    // Don't make a section of size 0.
    NtHdr->Pe32Plus.FileHeader.NumberOfSections--;
  }

  if ((mHiiRsrcOffset - mDataOffset) > 0) {
    CreateSectionHeader (".data", mDataOffset, mHiiRsrcOffset - mDataOffset,
            EFI_IMAGE_SCN_CNT_INITIALIZED_DATA
            | EFI_IMAGE_SCN_MEM_WRITE
            | EFI_IMAGE_SCN_MEM_READ);
  } else {
    // Don't make a section of size 0.
    NtHdr->Pe32Plus.FileHeader.NumberOfSections--;
  }

  if ((mRelocOffset - mHiiRsrcOffset) > 0) {
    CreateSectionHeader (".rsrc", mHiiRsrcOffset, mRelocOffset - mHiiRsrcOffset,
            EFI_IMAGE_SCN_CNT_INITIALIZED_DATA
            | EFI_IMAGE_SCN_MEM_READ);

    NtHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_RESOURCE].Size = mRelocOffset - mHiiRsrcOffset;
    NtHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_RESOURCE].VirtualAddress = mHiiRsrcOffset;
  } else {
    // Don't make a section of size 0.
    NtHdr->Pe32Plus.FileHeader.NumberOfSections--;
  }

}

STATIC
BOOLEAN
WriteSections64 (
  SECTION_FILTER_TYPES  FilterType
  )
{
  UINT32      Idx;
  Elf_Shdr    *SecShdr;
  UINT32      SecOffset;
  BOOLEAN     (*Filter)(Elf_Shdr *);

  //
  // Initialize filter pointer
  //
  switch (FilterType) {
    case SECTION_TEXT:
      Filter = IsTextShdr;
      break;
    case SECTION_HII:
      Filter = IsHiiRsrcShdr;
      break;
    case SECTION_DATA:
      Filter = IsDataShdr;
      break;
    default:
      return FALSE;
  }

  //
  // First: copy sections.
  //
  for (Idx = 0; Idx < mEhdr->e_shnum; Idx++) {
    Elf_Shdr *Shdr = GetShdrByIndex(Idx);
    if ((*Filter)(Shdr)) {
      switch (Shdr->sh_type) {
      case SHT_PROGBITS:
        /* Copy.  */
        memcpy(mCoffFile + mCoffSectionsOffset[Idx],
              (UINT8*)mEhdr + Shdr->sh_offset,
              (size_t) Shdr->sh_size);
        break;

      case SHT_NOBITS:
        memset(mCoffFile + mCoffSectionsOffset[Idx], 0, (size_t) Shdr->sh_size);
        break;

      default:
        //
        //  Ignore for unkown section type.
        //
        VerboseMsg ("%s unknown section type %x. We directly copy this section into Coff file", mInImageName, (unsigned)Shdr->sh_type);
        break;
      }
    }
  }

  //
  // Second: apply relocations.
  //
  VerboseMsg ("Applying Relocations...");
  for (Idx = 0; Idx < mEhdr->e_shnum; Idx++) {
    //
    // Determine if this is a relocation section.
    //
    Elf_Shdr *RelShdr = GetShdrByIndex(Idx);
    if ((RelShdr->sh_type != SHT_REL) && (RelShdr->sh_type != SHT_RELA)) {
      continue;
    }

    //
    // If this is a ET_DYN (PIE) executable, we will encounter a dynamic SHT_RELA
    // section that applies to the entire binary, and which will have its section
    // index set to #0 (which is a NULL section with the SHF_ALLOC bit cleared).
    //
    // In the absence of GOT based relocations (which we currently don't support),
    // this RELA section will contain redundant R_xxx_RELATIVE relocations, one
    // for every R_xxx_xx64 relocation appearing in the per-section RELA sections.
    // (i.e., .rela.text and .rela.data)
    //
    if (RelShdr->sh_info == 0) {
      continue;
    }

    //
    // Relocation section found.  Now extract section information that the relocations
    // apply to in the ELF data and the new COFF data.
    //
    SecShdr = GetShdrByIndex(RelShdr->sh_info);
    SecOffset = mCoffSectionsOffset[RelShdr->sh_info];

    //
    // Only process relocations for the current filter type.
    //
    if (RelShdr->sh_type == SHT_RELA && (*Filter)(SecShdr)) {
      UINT64 RelIdx;

      //
      // Determine the symbol table referenced by the relocation data.
      //
      Elf_Shdr *SymtabShdr = GetShdrByIndex(RelShdr->sh_link);
      UINT8 *Symtab = (UINT8*)mEhdr + SymtabShdr->sh_offset;

      //
      // Process all relocation entries for this section.
      //
      for (RelIdx = 0; RelIdx < RelShdr->sh_size; RelIdx += (UINT32) RelShdr->sh_entsize) {

        //
        // Set pointer to relocation entry
        //
        Elf_Rela *Rel = (Elf_Rela *)((UINT8*)mEhdr + RelShdr->sh_offset + RelIdx);

        //
        // Set pointer to symbol table entry associated with the relocation entry.
        //
        Elf_Sym  *Sym = (Elf_Sym *)(Symtab + ELF_R_SYM(Rel->r_info) * SymtabShdr->sh_entsize);

        Elf_Shdr *SymShdr;
        UINT8    *Targ;

        //
        // Check section header index found in symbol table and get the section
        // header location.
        //
        if (Sym->st_shndx == SHN_UNDEF
            || Sym->st_shndx >= mEhdr->e_shnum) {
          const UINT8 *SymName = GetSymName(Sym);
          if (SymName == NULL) {
            SymName = (const UINT8 *)"<unknown>";
          }

          Error (NULL, 0, 3000, "Invalid",
                 "%s: Bad definition for symbol '%s'@%#llx or unsupported symbol type.  "
                 "For example, absolute and undefined symbols are not supported.",
                 mInImageName, SymName, Sym->st_value);

          exit(EXIT_FAILURE);
        }
        SymShdr = GetShdrByIndex(Sym->st_shndx);

        //
        // Convert the relocation data to a pointer into the coff file.
        //
        // Note:
        //   r_offset is the virtual address of the storage unit to be relocated.
        //   sh_addr is the virtual address for the base of the section.
        //
        //   r_offset in a memory address.
        //   Convert it to a pointer in the coff file.
        //
        Targ = mCoffFile + SecOffset + (Rel->r_offset - SecShdr->sh_addr);

        //
        // Determine how to handle each relocation type based on the machine type.
        //
        if (mEhdr->e_machine == EM_X86_64) {
          switch (ELF_R_TYPE(Rel->r_info)) {
          case R_X86_64_NONE:
            break;
          case R_X86_64_64:
            //
            // Absolute relocation.
            //
            VerboseMsg ("R_X86_64_64");
            VerboseMsg ("Offset: 0x%08X, Addend: 0x%016LX", 
              (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)), 
              *(UINT64 *)Targ);
            *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx];
            VerboseMsg ("Relocation:  0x%016LX", *(UINT64*)Targ);
            break;
          case R_X86_64_32:
            VerboseMsg ("R_X86_64_32");
            VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X", 
              (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)), 
              *(UINT32 *)Targ);
            *(UINT32 *)Targ = (UINT32)((UINT64)(*(UINT32 *)Targ) - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx]);
            VerboseMsg ("Relocation:  0x%08X", *(UINT32*)Targ);
            break;
          case R_X86_64_32S:
            VerboseMsg ("R_X86_64_32S");
            VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X", 
              (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)), 
              *(UINT32 *)Targ);
            *(INT32 *)Targ = (INT32)((INT64)(*(INT32 *)Targ) - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx]);
            VerboseMsg ("Relocation:  0x%08X", *(UINT32*)Targ);
            break;

          case R_X86_64_PLT32:
            //
            // Treat R_X86_64_PLT32 relocations as R_X86_64_PC32: this is
            // possible since we know all code symbol references resolve to
            // definitions in the same module (UEFI has no shared libraries),
            // and so there is never a reason to jump via a PLT entry,
            // allowing us to resolve the reference using the symbol directly.
            //
            VerboseMsg ("Treating R_X86_64_PLT32 as R_X86_64_PC32 ...");
            /* fall through */
          case R_X86_64_PC32:
            //
            // Relative relocation: Symbol - Ip + Addend
            //
            VerboseMsg ("R_X86_64_PC32");
            VerboseMsg ("Offset: 0x%08X, Addend: 0x%08X", 
              (UINT32)(SecOffset + (Rel->r_offset - SecShdr->sh_addr)), 
              *(UINT32 *)Targ);
            *(UINT32 *)Targ = (UINT32) (*(UINT32 *)Targ
              + (mCoffSectionsOffset[Sym->st_shndx] - SymShdr->sh_addr)
              - (SecOffset - SecShdr->sh_addr));
            VerboseMsg ("Relocation:  0x%08X", *(UINT32 *)Targ);
            break;
          default:
            Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64 relocation 0x%x.", mInImageName, (unsigned) ELF_R_TYPE(Rel->r_info));
          }
        } else if (mEhdr->e_machine == EM_AARCH64) {

          switch (ELF_R_TYPE(Rel->r_info)) {

          case R_AARCH64_ADR_PREL_PG_HI21:
            //
            // AArch64 PG_H21 relocations are typically paired with ABS_LO12
            // relocations, where a PC-relative reference with +/- 4 GB range is
            // split into a relative high part and an absolute low part. Since
            // the absolute low part represents the offset into a 4 KB page, we
            // either have to convert the ADRP into an ADR instruction, or we
            // need to use a section alignment of at least 4 KB, so that the
            // binary appears at a correct offset at runtime. In any case, we
            // have to make sure that the 4 KB relative offsets of both the
            // section containing the reference as well as the section to which
            // it refers have not been changed during PE/COFF conversion (i.e.,
            // in ScanSections64() above).
            //
            if (mCoffAlignment < 0x1000) {
              //
              // Attempt to convert the ADRP into an ADR instruction.
              // This is only possible if the symbol is within +/- 1 MB.
              //
              INT64 Offset;

              // Decode the ADRP instruction
              Offset = (INT32)((*(UINT32 *)Targ & 0xffffe0) << 8);
              Offset = (Offset << (6 - 5)) | ((*(UINT32 *)Targ & 0x60000000) >> (29 - 12));

              //
              // ADRP offset is relative to the previous page boundary,
              // whereas ADR offset is relative to the instruction itself.
              // So fix up the offset so it points to the page containing
              // the symbol.
              //
              Offset -= (UINTN)(Targ - mCoffFile) & 0xfff;

              if (Offset < -0x100000 || Offset > 0xfffff) {
                Error (NULL, 0, 3000, "Invalid", "WriteSections64(): %s  due to its size (> 1 MB), this module requires 4 KB section alignment.",
                  mInImageName);
                break;
              }

              // Re-encode the offset as an ADR instruction
              *(UINT32 *)Targ &= 0x1000001f;
              *(UINT32 *)Targ |= ((Offset & 0x1ffffc) << (5 - 2)) | ((Offset & 0x3) << 29);
            }
            /* fall through */

          case R_AARCH64_ADD_ABS_LO12_NC:
          case R_AARCH64_LDST8_ABS_LO12_NC:
          case R_AARCH64_LDST16_ABS_LO12_NC:
          case R_AARCH64_LDST32_ABS_LO12_NC:
          case R_AARCH64_LDST64_ABS_LO12_NC:
          case R_AARCH64_LDST128_ABS_LO12_NC:
            if (((SecShdr->sh_addr ^ SecOffset) & 0xfff) != 0 ||
                ((SymShdr->sh_addr ^ mCoffSectionsOffset[Sym->st_shndx]) & 0xfff) != 0) {
              Error (NULL, 0, 3000, "Invalid", "WriteSections64(): %s AARCH64 small code model requires identical ELF and PE/COFF section offsets modulo 4 KB.",
                mInImageName);
              break;
            }
            /* fall through */

          case R_AARCH64_ADR_PREL_LO21:
          case R_AARCH64_CONDBR19:
          case R_AARCH64_LD_PREL_LO19:
          case R_AARCH64_CALL26:
          case R_AARCH64_JUMP26:
          case R_AARCH64_PREL64:
          case R_AARCH64_PREL32:
          case R_AARCH64_PREL16:
            //
            // The GCC toolchains (i.e., binutils) may corrupt section relative
            // relocations when emitting relocation sections into fully linked
            // binaries. More specifically, they tend to fail to take into
            // account the fact that a '.rodata + XXX' relocation needs to have
            // its addend recalculated once .rodata is merged into the .text
            // section, and the relocation emitted into the .rela.text section.
            //
            // We cannot really recover from this loss of information, so the
            // only workaround is to prevent having to recalculate any relative
            // relocations at all, by using a linker script that ensures that
            // the offset between the Place and the Symbol is the same in both
            // the ELF and the PE/COFF versions of the binary.
            //
            if ((SymShdr->sh_addr - SecShdr->sh_addr) !=
                (mCoffSectionsOffset[Sym->st_shndx] - SecOffset)) {
              Error (NULL, 0, 3000, "Invalid", "WriteSections64(): %s AARCH64 relative relocations require identical ELF and PE/COFF section offsets",
                mInImageName);
            }
            break;

          // Absolute relocations.
          case R_AARCH64_ABS64:
            *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx];
            break;

          default:
            Error (NULL, 0, 3000, "Invalid", "WriteSections64(): %s unsupported ELF EM_AARCH64 relocation 0x%x.", mInImageName, (unsigned) ELF_R_TYPE(Rel->r_info));
          }
        } else {
          Error (NULL, 0, 3000, "Invalid", "Not a supported machine type");
        }
      }
    }
  }

  return TRUE;
}

STATIC
VOID
WriteRelocations64 (
  VOID
  )
{
  UINT32                           Index;
  EFI_IMAGE_OPTIONAL_HEADER_UNION  *NtHdr;
  EFI_IMAGE_DATA_DIRECTORY         *Dir;

  for (Index = 0; Index < mEhdr->e_shnum; Index++) {
    Elf_Shdr *RelShdr = GetShdrByIndex(Index);
    if ((RelShdr->sh_type == SHT_REL) || (RelShdr->sh_type == SHT_RELA)) {
      Elf_Shdr *SecShdr = GetShdrByIndex (RelShdr->sh_info);
      if (IsTextShdr(SecShdr) || IsDataShdr(SecShdr)) {
        UINT64 RelIdx;

        for (RelIdx = 0; RelIdx < RelShdr->sh_size; RelIdx += RelShdr->sh_entsize) {
          Elf_Rela *Rel = (Elf_Rela *)((UINT8*)mEhdr + RelShdr->sh_offset + RelIdx);

          if (mEhdr->e_machine == EM_X86_64) {
            switch (ELF_R_TYPE(Rel->r_info)) {
            case R_X86_64_NONE:
            case R_X86_64_PC32:
            case R_X86_64_PLT32:
              break;
            case R_X86_64_64:
              VerboseMsg ("EFI_IMAGE_REL_BASED_DIR64 Offset: 0x%08X", 
                mCoffSectionsOffset[RelShdr->sh_info] + (Rel->r_offset - SecShdr->sh_addr));
              CoffAddFixup(
                (UINT32) ((UINT64) mCoffSectionsOffset[RelShdr->sh_info]
                + (Rel->r_offset - SecShdr->sh_addr)),
                EFI_IMAGE_REL_BASED_DIR64);
              break;
            case R_X86_64_32S:
            case R_X86_64_32:
              VerboseMsg ("EFI_IMAGE_REL_BASED_HIGHLOW Offset: 0x%08X", 
                mCoffSectionsOffset[RelShdr->sh_info] + (Rel->r_offset - SecShdr->sh_addr));
              CoffAddFixup(
                (UINT32) ((UINT64) mCoffSectionsOffset[RelShdr->sh_info]
                + (Rel->r_offset - SecShdr->sh_addr)),
                EFI_IMAGE_REL_BASED_HIGHLOW);
              break;
            default:
              Error (NULL, 0, 3000, "Invalid", "%s unsupported ELF EM_X86_64 relocation 0x%x.", mInImageName, (unsigned) ELF_R_TYPE(Rel->r_info));
            }
          } else if (mEhdr->e_machine == EM_AARCH64) {

            switch (ELF_R_TYPE(Rel->r_info)) {
            case R_AARCH64_ADR_PREL_LO21:
            case R_AARCH64_CONDBR19:
            case R_AARCH64_LD_PREL_LO19:
            case R_AARCH64_CALL26:
            case R_AARCH64_JUMP26:
            case R_AARCH64_PREL64:
            case R_AARCH64_PREL32:
            case R_AARCH64_PREL16:
            case R_AARCH64_ADR_PREL_PG_HI21:
            case R_AARCH64_ADD_ABS_LO12_NC:
            case R_AARCH64_LDST8_ABS_LO12_NC:
            case R_AARCH64_LDST16_ABS_LO12_NC:
            case R_AARCH64_LDST32_ABS_LO12_NC:
            case R_AARCH64_LDST64_ABS_LO12_NC:
            case R_AARCH64_LDST128_ABS_LO12_NC:
              //
              // No fixups are required for relative relocations, provided that
              // the relative offsets between sections have been preserved in
              // the ELF to PE/COFF conversion. We have already asserted that
              // this is the case in WriteSections64 ().
              //
              break;

            case R_AARCH64_ABS64:
              CoffAddFixup(
                (UINT32) ((UINT64) mCoffSectionsOffset[RelShdr->sh_info]
                + (Rel->r_offset - SecShdr->sh_addr)),
                EFI_IMAGE_REL_BASED_DIR64);
              break;

            case R_AARCH64_ABS32:
              CoffAddFixup(
                (UINT32) ((UINT64) mCoffSectionsOffset[RelShdr->sh_info]
                + (Rel->r_offset - SecShdr->sh_addr)),
                EFI_IMAGE_REL_BASED_HIGHLOW);
             break;

            default:
                Error (NULL, 0, 3000, "Invalid", "WriteRelocations64(): %s unsupported ELF EM_AARCH64 relocation 0x%x.", mInImageName, (unsigned) ELF_R_TYPE(Rel->r_info));
            }
          } else {
            Error (NULL, 0, 3000, "Not Supported", "This tool does not support relocations for ELF with e_machine %u (processor type).", (unsigned) mEhdr->e_machine);
          }
        }
      }
    }
  }

  //
  // Pad by adding empty entries.
  //
  while (mCoffOffset & (mCoffAlignment - 1)) {
    CoffAddFixupEntry(0);
  }

  NtHdr = (EFI_IMAGE_OPTIONAL_HEADER_UNION *)(mCoffFile + mNtHdrOffset);
  Dir = &NtHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC];
  Dir->Size = mCoffOffset - mRelocOffset;
  if (Dir->Size == 0) {
    // If no relocations, null out the directory entry and don't add the .reloc section
    Dir->VirtualAddress = 0;
    NtHdr->Pe32Plus.FileHeader.NumberOfSections--;
  } else {
    Dir->VirtualAddress = mRelocOffset;
    CreateSectionHeader (".reloc", mRelocOffset, mCoffOffset - mRelocOffset,
            EFI_IMAGE_SCN_CNT_INITIALIZED_DATA
            | EFI_IMAGE_SCN_MEM_DISCARDABLE
            | EFI_IMAGE_SCN_MEM_READ);
  }
}

STATIC
VOID
WriteDebug64 (
  VOID
  )
{
  UINT32                              Len;
  EFI_IMAGE_OPTIONAL_HEADER_UNION     *NtHdr;
  EFI_IMAGE_DATA_DIRECTORY            *DataDir;
  EFI_IMAGE_DEBUG_DIRECTORY_ENTRY     *Dir;
  EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY *Nb10;

  Len = strlen(mInImageName) + 1;

  Dir = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY*)(mCoffFile + mDebugOffset);
  Dir->Type = EFI_IMAGE_DEBUG_TYPE_CODEVIEW;
  Dir->SizeOfData = sizeof(EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY) + Len;
  Dir->RVA = mDebugOffset + sizeof(EFI_IMAGE_DEBUG_DIRECTORY_ENTRY);
  Dir->FileOffset = mDebugOffset + sizeof(EFI_IMAGE_DEBUG_DIRECTORY_ENTRY);

  Nb10 = (EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY*)(Dir + 1);
  Nb10->Signature = CODEVIEW_SIGNATURE_NB10;
  strcpy ((char *)(Nb10 + 1), mInImageName);


  NtHdr = (EFI_IMAGE_OPTIONAL_HEADER_UNION *)(mCoffFile + mNtHdrOffset);
  DataDir = &NtHdr->Pe32Plus.OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG];
  DataDir->VirtualAddress = mDebugOffset;
  DataDir->Size = sizeof(EFI_IMAGE_DEBUG_DIRECTORY_ENTRY);
}

STATIC
VOID
SetImageSize64 (
  VOID
  )
{
  EFI_IMAGE_OPTIONAL_HEADER_UNION *NtHdr;

  //
  // Set image size
  //
  NtHdr = (EFI_IMAGE_OPTIONAL_HEADER_UNION *)(mCoffFile + mNtHdrOffset);
  NtHdr->Pe32Plus.OptionalHeader.SizeOfImage = mCoffOffset;
}

STATIC
VOID
CleanUp64 (
  VOID
  )
{
  if (mCoffSectionsOffset != NULL) {
    free (mCoffSectionsOffset);
  }
}