How can I enable my 32-bit Delphi application to use 4gb of memory on 64-bit windows (via Wow64.exe)?

Question

According to this MSDN page:

WOW64 enables 32-bit applications to take advantage of the 64-bit kernel. Therefore, 32-bit applications can use a

Answer 1

Use the linker directive $SetPEFlags:

{$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE}

The IMAGE_FILE_LARGE_ADDRESS_AWARE constant is defined in Windows.pas. I don't remember which Delphi version first included it, though.

In Delphi 2007, you'll find SetPEFlags documented in "PE (portable executable) header flags (Delphi)".

Some useful IMAGE_FILE_HEADER flags:

• {$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE} //$0020

  Application can handle addresses larger than 2 GB.

• {$SetPEFlags IMAGE_FILE_NET_RUN_FROM_SWAP} //$0800

  If the image is on the network, copy it to and run it from the swap file.

• {$SetPEFlags IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP} //$0400

  If the image is on removable media, copy it to and run it from the swap file.

Some IMAGE_FILE_HEADER flags:

• {$SetPEOptFlags IMAGE_DLLCHARACTERISTICS_NX_COMPAT} //$0100

  The image is compatible with data execution prevention (DEP).

• {$SetPEOptFlags IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE} //$0040

  The DLL can be relocated at load time. (aka ASLR - Address Space Layout Randomization)

• {$SetPEOptFlags IMAGE_DLLCHARACTERISTICS_TERMINAL_SERVER_AWARE} //$8000

  The image is terminal server aware.