/** @file
  Provides the services to get the entry point to a PE/COFF image that has either been
  loaded into memory or is executing at it's linked address.

  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <Base.h>

#include <Library/PeCoffGetEntryPointLib.h>
#include <Library/DebugLib.h>

#include <IndustryStandard/PeImage.h>

#define PE_COFF_IMAGE_ALIGN_SIZE  4

/**
  Retrieves and returns a pointer to the entry point to a PE/COFF image that has been loaded
  into system memory with the PE/COFF Loader Library functions.

  Retrieves the entry point to the PE/COFF image specified by Pe32Data and returns this entry
  point in EntryPoint.  If the entry point could not be retrieved from the PE/COFF image, then
  return RETURN_INVALID_PARAMETER.  Otherwise return RETURN_SUCCESS.
  If Pe32Data is NULL, then ASSERT().
  If EntryPoint is NULL, then ASSERT().

  @param  Pe32Data                  The pointer to the PE/COFF image that is loaded in system memory.
  @param  EntryPoint                The pointer to entry point to the PE/COFF image to return.

  @retval RETURN_SUCCESS            EntryPoint was returned.
  @retval RETURN_INVALID_PARAMETER  The entry point could not be found in the PE/COFF image.

**/
RETURN_STATUS
EFIAPI
PeCoffLoaderGetEntryPoint (
  IN  VOID  *Pe32Data,
  OUT VOID  **EntryPoint
  )
{
  EFI_IMAGE_DOS_HEADER                 *DosHdr;
  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr;

  ASSERT (Pe32Data   != NULL);
  ASSERT (EntryPoint != NULL);

  DosHdr = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
  if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
    //
    // DOS image header is present, so read the PE header after the DOS image header.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN)Pe32Data + (UINTN)((DosHdr->e_lfanew) & 0x0ffff));
  } else {
    //
    // DOS image header is not present, so PE header is at the image base.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;
  }

  //
  // Calculate the entry point relative to the start of the image.
  // AddressOfEntryPoint is common for PE32 & PE32+
  //
  if (Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) {
    *EntryPoint = (VOID *)((UINTN)Pe32Data + (UINTN)(Hdr.Te->AddressOfEntryPoint & 0x0ffffffff) + sizeof (EFI_TE_IMAGE_HEADER) - Hdr.Te->StrippedSize);
    return RETURN_SUCCESS;
  } else if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) {
    *EntryPoint = (VOID *)((UINTN)Pe32Data + (UINTN)(Hdr.Pe32->OptionalHeader.AddressOfEntryPoint & 0x0ffffffff));
    return RETURN_SUCCESS;
  }

  return RETURN_UNSUPPORTED;
}

/**
  Returns the machine type of a PE/COFF image.

  Returns the machine type from the PE/COFF image specified by Pe32Data.
  If Pe32Data is NULL, then ASSERT().

  @param  Pe32Data   The pointer to the PE/COFF image that is loaded in system
                     memory.

  @return Machine type or zero if not a valid image.

**/
UINT16
EFIAPI
PeCoffLoaderGetMachineType (
  IN VOID  *Pe32Data
  )
{
  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr;
  EFI_IMAGE_DOS_HEADER                 *DosHdr;

  ASSERT (Pe32Data != NULL);

  DosHdr = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
  if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
    //
    // DOS image header is present, so read the PE header after the DOS image header.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN)Pe32Data + (UINTN)((DosHdr->e_lfanew) & 0x0ffff));
  } else {
    //
    // DOS image header is not present, so PE header is at the image base.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;
  }

  if (Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) {
    return Hdr.Te->Machine;
  } else if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) {
    return Hdr.Pe32->FileHeader.Machine;
  }

  return 0x0000;
}

/**
  Returns a pointer to the PDB file name for a PE/COFF image that has been
  loaded into system memory with the PE/COFF Loader Library functions.

  Returns the PDB file name for the PE/COFF image specified by Pe32Data.  If
  the PE/COFF image specified by Pe32Data is not a valid, then NULL is
  returned.  If the PE/COFF image specified by Pe32Data does not contain a
  debug directory entry, then NULL is returned.  If the debug directory entry
  in the PE/COFF image specified by Pe32Data does not contain a PDB file name,
  then NULL is returned.
  If Pe32Data is NULL, then ASSERT().

  @param  Pe32Data   The pointer to the PE/COFF image that is loaded in system
                     memory.

  @return The PDB file name for the PE/COFF image specified by Pe32Data or NULL
          if it cannot be retrieved.

**/
VOID *
EFIAPI
PeCoffLoaderGetPdbPointer (
  IN VOID  *Pe32Data
  )
{
  EFI_IMAGE_DOS_HEADER                 *DosHdr;
  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr;
  EFI_IMAGE_DATA_DIRECTORY             *DirectoryEntry;
  EFI_IMAGE_DEBUG_DIRECTORY_ENTRY      *DebugEntry;
  UINTN                                DirCount;
  VOID                                 *CodeViewEntryPointer;
  INTN                                 TEImageAdjust;
  UINT32                               NumberOfRvaAndSizes;
  UINT16                               Magic;

  ASSERT (Pe32Data   != NULL);

  TEImageAdjust       = 0;
  DirectoryEntry      = NULL;
  DebugEntry          = NULL;
  NumberOfRvaAndSizes = 0;

  DosHdr = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
  if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
    //
    // DOS image header is present, so read the PE header after the DOS image header.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN)Pe32Data + (UINTN)((DosHdr->e_lfanew) & 0x0ffff));
  } else {
    //
    // DOS image header is not present, so PE header is at the image base.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;
  }

  if (Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) {
    if (Hdr.Te->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress != 0) {
      DirectoryEntry = &Hdr.Te->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_DEBUG];
      TEImageAdjust  = sizeof (EFI_TE_IMAGE_HEADER) - Hdr.Te->StrippedSize;
      DebugEntry     = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *)((UINTN)Hdr.Te +
                                                           Hdr.Te->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress +
                                                           TEImageAdjust);
    }
  } else if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) {
    //
    // NOTE: We use Machine field to identify PE32/PE32+, instead of Magic.
    //       It is due to backward-compatibility, for some system might
    //       generate PE32+ image with PE32 Magic.
    //
    switch (Hdr.Pe32->FileHeader.Machine) {
      case IMAGE_FILE_MACHINE_I386:
        //
        // Assume PE32 image with IA32 Machine field.
        //
        Magic = EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC;
        break;
      case IMAGE_FILE_MACHINE_X64:
      case IMAGE_FILE_MACHINE_IA64:
        //
        // Assume PE32+ image with x64 or IA64 Machine field
        //
        Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
        break;
      default:
        //
        // For unknow Machine field, use Magic in optional Header
        //
        Magic = Hdr.Pe32->OptionalHeader.Magic;
    }

    if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
      //
      // Use PE32 offset get Debug Directory Entry
      //
      NumberOfRvaAndSizes = Hdr.Pe32->OptionalHeader.NumberOfRvaAndSizes;
      DirectoryEntry      = (EFI_IMAGE_DATA_DIRECTORY *)&(Hdr.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG]);
      DebugEntry          = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *)((UINTN)Pe32Data + DirectoryEntry->VirtualAddress);
    } else if (Hdr.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
      //
      // Use PE32+ offset get Debug Directory Entry
      //
      NumberOfRvaAndSizes = Hdr.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;
      DirectoryEntry      = (EFI_IMAGE_DATA_DIRECTORY *)&(Hdr.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG]);
      DebugEntry          = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *)((UINTN)Pe32Data + DirectoryEntry->VirtualAddress);
    }

    if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_DEBUG) {
      DirectoryEntry = NULL;
      DebugEntry     = NULL;
    }
  } else {
    return NULL;
  }

  if ((DebugEntry == NULL) || (DirectoryEntry == NULL)) {
    return NULL;
  }

  //
  // Scan the directory to find the debug entry.
  //
  for (DirCount = 0; DirCount < DirectoryEntry->Size; DirCount += sizeof (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY), DebugEntry++) {
    if (DebugEntry->Type == EFI_IMAGE_DEBUG_TYPE_CODEVIEW) {
      if (DebugEntry->SizeOfData > 0) {
        CodeViewEntryPointer = (VOID *)((UINTN)DebugEntry->RVA + ((UINTN)Pe32Data) + (UINTN)TEImageAdjust);
        switch (*(UINT32 *)CodeViewEntryPointer) {
          case CODEVIEW_SIGNATURE_NB10:
            return (VOID *)((CHAR8 *)CodeViewEntryPointer + sizeof (EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY));
          case CODEVIEW_SIGNATURE_RSDS:
            return (VOID *)((CHAR8 *)CodeViewEntryPointer + sizeof (EFI_IMAGE_DEBUG_CODEVIEW_RSDS_ENTRY));
          case CODEVIEW_SIGNATURE_MTOC:
            return (VOID *)((CHAR8 *)CodeViewEntryPointer + sizeof (EFI_IMAGE_DEBUG_CODEVIEW_MTOC_ENTRY));
          default:
            break;
        }
      }
    }
  }

  return NULL;
}

/**
  Returns the size of the PE/COFF headers

  Returns the size of the PE/COFF header specified by Pe32Data.
  If Pe32Data is NULL, then ASSERT().

  @param  Pe32Data   The pointer to the PE/COFF image that is loaded in system
                     memory.

  @return Size of PE/COFF header in bytes or zero if not a valid image.

**/
UINT32
EFIAPI
PeCoffGetSizeOfHeaders (
  IN VOID  *Pe32Data
  )
{
  EFI_IMAGE_DOS_HEADER                 *DosHdr;
  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr;
  UINTN                                SizeOfHeaders;

  ASSERT (Pe32Data   != NULL);

  DosHdr = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
  if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
    //
    // DOS image header is present, so read the PE header after the DOS image header.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN)Pe32Data + (UINTN)((DosHdr->e_lfanew) & 0x0ffff));
  } else {
    //
    // DOS image header is not present, so PE header is at the image base.
    //
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;
  }

  if (Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) {
    SizeOfHeaders = sizeof (EFI_TE_IMAGE_HEADER) + (UINTN)Hdr.Te->BaseOfCode - (UINTN)Hdr.Te->StrippedSize;
  } else if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) {
    SizeOfHeaders = Hdr.Pe32->OptionalHeader.SizeOfHeaders;
  } else {
    SizeOfHeaders = 0;
  }

  return (UINT32)SizeOfHeaders;
}

/**
  Returns PE/COFF image base is loaded in system memory where the input address is in.

  On DEBUG build, searches the PE/COFF image base forward the input address and
  returns it.

  @param  Address    Address located in one PE/COFF image.

  @retval 0          RELEASE build or cannot find the PE/COFF image base.
  @retval others     PE/COFF image base found.

**/
UINTN
EFIAPI
PeCoffSearchImageBase (
  IN UINTN  Address
  )
{
  UINTN  Pe32Data;

  Pe32Data = 0;

  DEBUG_CODE_BEGIN ();
  EFI_IMAGE_DOS_HEADER                 *DosHdr;
  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr;

  //
  // Find Image Base
  //
  Pe32Data = Address & ~(PE_COFF_IMAGE_ALIGN_SIZE - 1);
  while (Pe32Data != 0) {
    DosHdr = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
    if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
      //
      // DOS image header is present, so read the PE header after the DOS image header.
      //
      Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)(Pe32Data + (UINTN)((DosHdr->e_lfanew) & 0x0ffff));
      //
      // Make sure PE header address does not overflow and is less than the initial address.
      //
      if (((UINTN)Hdr.Pe32 > Pe32Data) && ((UINTN)Hdr.Pe32 < Address)) {
        if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) {
          break;
        }
      }
    } else {
      //
      // DOS image header is not present, TE header is at the image base.
      //
      Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;
      if ((Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) &&
          ((Hdr.Te->Machine == IMAGE_FILE_MACHINE_I386)  || (Hdr.Te->Machine == IMAGE_FILE_MACHINE_IA64) ||
           (Hdr.Te->Machine == IMAGE_FILE_MACHINE_EBC)   || (Hdr.Te->Machine == IMAGE_FILE_MACHINE_X64)  ||
           (Hdr.Te->Machine == IMAGE_FILE_MACHINE_ARM64) || (Hdr.Te->Machine == IMAGE_FILE_MACHINE_ARMTHUMB_MIXED))
          )
      {
        break;
      }
    }

    //
    // Not found the image base, check the previous aligned address
    //
    Pe32Data -= PE_COFF_IMAGE_ALIGN_SIZE;
  }

  DEBUG_CODE_END ();

  return Pe32Data;
}