Static linking of 16-bit and 32-bit code

[jj2007]

I wonder if it is possible to link 16-bit lib or obj files with 32-bit lib or obj files.

Related: How can you use the 16-bit LoadLibrary call in assembler?

Any ideas?

[dedndave]

google the term "thunk"
although, i can't imagine why   :P

[jj2007]

google the term "thunk"
although, i can't imagine why   :P

Thunking from 16-bit Windows 3.1 code to a 32-bit DLL is easy, but that's not the problem. I'd like to link statically.

[japheth]

I'd like to link statically.

That's no problem - so long as you don't try to call the 16-bit code. There's no relocation type for a 16-bit far call in the PE format.

[jj2007]

I'd like to call the 32-bit code from the 16-bit code. One option I see is to load relocatable 32-bit code into 16-bit memory, and call it from there with CallProc32W.

But how can I get the address of CallProc32W from a 16-bit DOS program?

[sinsi]

You might have to put the 32-bit code in a dll.

Windows NT, Windows 95, Windows 98, and Windows 2000 do not allow direct mixing of 16-bit code and 32-bit code in the same process.

Generic thunks allow a 16-bit Windows-based application to load and call a Win32-based DLL.

http://support.microsoft.com/kb/125710

[japheth]

But how can I get the address of CallProc32W from a 16-bit DOS program?

I'd say that's not possible.

A 16-bit DOS real-mode program in XP that wants to execute 32-bit may do

- call exports of a Win32 dll ( using so-called BOPs )    OR
- switch to protected-mode via DPMI and then call 32-bit code directly ( after having done some low-level selector stuff ).

[sinsi]

Oops, didn't see the DOS bit. Maybe your DOS program could talk to a 16-bit Windows .vxd which could then talk to a 32-bit .dll

[jj2007]

You might have to put the 32-bit code in a dll.

That's what I always did, but I'd like to go the static linking route. BOPs sounds interesting, though. Actually, it's a 16-bit Win app that calls the code, but for testing, 16-bit console would be nice...

[sinsi]

http://www.masmforum.com/board/index.php?topic=12823;prev_next=next

[jj2007]

Thanks, John & Dave & Japheth - I knew I had seen that BOP stuff before ;-)