Assembly

fbkotler · Joined: 05 Oct 2009 Posts: 5 Location: New Hampshire, USA

Klod and I are trying to discuss this on the SourceForge Nasm beginner's questions forum. It has become impossible. I think what he's trying to do is...

;-------------------
%define ddBlah(x) ddBlah+HighLow %+x
EXTERN wsprintfA
EXTERN ExitProcess
EXTERN MsgBox
STRUC HighLow
.High RESW 1
.Low RESW 1
ENDSTRUC

SECTION .data
ddBlah DD 123456789
strFmt DB `High Word: %d\nLow Word: %d\n`, 0
buffer TIMES 1024 db 0
caption db 'Testing',0
SECTION .text
Global Start
Start:
movzx eax,WORD[ddBlah+HighLow.High] ;access the structure with Nasm notation
movzx ebx,WORD[ddBlah+HighLow.Low] ; to prove out the program
Mov Ax, ddBlah(Low) ;assembled -e option Mov Ax, ddBlah+HighLowLow
Mov Bx, ddBlah(.High) ;assembled -e option Mov Bx, ddBlah+HighLow.High
This is what I wanted
Push Eax
Push Ebx
Push DWORD strFmt
push dword buffer
Call wsprintfA
push caption
push buffer
call MsgBox
push 0
call ExitProcess
;Radasm IDE 3,O,$B\NASM -Ox -fwin32 ,2 ;latest version from download
;$.exe,O,$B\GoLink.EXE @$B\GFL.txt /debug coff /entry Start ,3`

> > These are the two errors I get for obove code sample
MacroTest.asm:24: error: symbol `HighLowLow' undefined
MacroTest.asm:25: error: COFF format does not support non-32-bit relocations

As can be seen from the -e assembly Mov Bx, ddBlah(.High) assembled to Mov
Bx, ddBlah+HighLow.High, what I wanted but I get MacroTest.asm:25: error: COFF
format does not support non-32-bit relocations

Do you have any suggestions or known workarounds?
--------------------------------

Well, you're not going to be able to mov a 32-bit address into a 16-bit register. Use a 32-bit register, or perhaps "Mov Bx, [ddBlah(.High)]".

I should note that you've got ".High" and ".Low" reversed from their usual usage...

If this works out better than the SF forum, talk to ya soon!

Best,
Frank

Klod · Joined: 05 Oct 2009 Posts: 5

Hi Frank, I finally activated my account and it looks like I on board
Klod

fbkotler · Joined: 05 Oct 2009 Posts: 5 Location: New Hampshire, USA

So, is it working for you? I don't see what you're trying to do with "mov reg16, 32-bit address"...

Best,
Frank

Klod · Joined: 05 Oct 2009 Posts: 5

This was a test program Synfire had worked out and works on Linux.
For some reason I cannot make it work on win32 XP pro
I would have liked to attach it as a zip file, but this forum does not support it. Here is the code:

fbkotler · Joined: 05 Oct 2009 Posts: 5 Location: New Hampshire, USA

Hi Klod,

Being able to attach a .zip file would be nice, but I cut 'n pasted your code - works fine for me(!). This is on Linux, but assembled as "-f win32". I can't run it, of course, or even link the object file, but Nasm does its part without complaint, and adding the "-e" switch looks "as intended".

Linux and Windows builds of Nasm use exactly the same source code (#IFDEFs excepted). Interfacing with the OS (file I/O and memory management, mostly) is completely different, but "text bashing" should be the same. However, there are subtle differences between compilers. (very recent versions of gcc are more aggressive about what's "allowed" between "sequence points", for example)

If this really turns out to work on Linux, but not on Windows, it may make a difference whether you downloaded a precompiled binary or built it yourself. If this turns out to be an issue, SpooK is the logical guy to discuss it with (he wrote the 64-bit extensions for outcoff.c... and outmacho.c...)

I would point out that "add esp, 4 * 3" is no longer correct, but that shouldn't matter to this issue...

Best,
Frank

Klod · Joined: 05 Oct 2009 Posts: 5

Hi Frank,
I was in a hurry this morning when I posted. The code sample I had originaly posted was I test piece.

fbkotler · Joined: 05 Oct 2009 Posts: 5 Location: New Hampshire, USA

The line you posted:

%define %{1}(x) ddBlah+HighLow %+x

lacks a space after "%+", which the docs claim is required. Works okay for me that way, too...

"mov ax, ???" shouldn't need a "word" qualifier - the register size specifies the operation size... If "???" is a 32-bit address, you get that "COFF does not support non-32-bit relocations" error - different issue.

I can't seem to duplicate this problem of "x" or "_x_" being treated as a string instead of a parameter. You might try "%xdefine" and see if it helps. Try it with a space after "%+", too...

Of course, you could always switch to Linux. :)

Best,
Frank

Klod · Joined: 05 Oct 2009 Posts: 5

Hi Frank
thanks for your reply
I have a brutal week behind me and I'm mentally drained.
Sorry, I copied the wrong statement, should have been
Mov Bx, ddBlah(.High) ;Mov EBX,ddBlah(.High)
Believe me, I tried every possible combination of arrangements of the parameters. including the %+ x.

I have copied Synfires test code into a text file, assembled it and it fails. I uploaded the file back. I compiled it on 3 different machines, (2 XP pro and 1 XP Home) and it fails with the same error messages on all.
http://www.asmcommunity.net/board/index.php?topic=29571.msg209046#msg209046
I hoped other window users would download it, compile it on real window hardware and voila.... So as it stands -->Klod bad Nasm good
It appears that I'm the only NASM user on windows???

I will give this thread a rest for a while and continue using Nasm's normal syntax/

Thanks for your help
Klod

fbkotler · Joined: 05 Oct 2009 Posts: 5 Location: New Hampshire, USA

Maybe "Nasm good, Nasm-for-Windows bad".

I agree that it's time to give this thread a rest. In order to download your/SpooK's test file, I hadda join their club. Maybe see you around there...

Best,
Frank