Here's a gem I found today

/**
  Retrieves the magic value from the PE/COFF header.
  
  @param  Hdr             The buffer in which to return the PE32, PE32+, or TE header.
    
  @return EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC - Image is PE32
  @return EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC - Image is PE32+

**/
UINT16
PeCoffLoaderGetPeHeaderMagicValue (
  IN  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr
  )
{
  //
  // NOTE: Some versions of Linux ELILO for Itanium have an incorrect magic value 
  //       in the PE/COFF Header.  If the MachineType is Itanium(IA64) and the 
  //       Magic value in the OptionalHeader is  EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC
  //       then override the returned value to EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC
  //  
  if (Hdr.Pe32->FileHeader.Machine == IMAGE_FILE_MACHINE_IA64 && Hdr.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
    return EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;
  }
  //
  // Return the magic value from the PC/COFF Optional Header
  //
  return Hdr.Pe32->OptionalHeader.Magic;
}