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Cthulhu



Joined: 12 May 2005
Posts: 29
Cthulhu
Hello folks!
I'm doing some experiments with Fasm, but in my first try I had the following problem:
Code:
format PE GUI 4.0
entry start

include 'include\win32a.inc'

;---------------
;secao de dados
;---------------
section '.1' data readable writeable

        DumbString db "Hello world!",0
        DumbTitle db "Dumb Title",0
        
;---------------
;secao de codigo
;---------------
section '.2' code readable executable
        
        start:
                push 0
                push DumbTitle
                push DumbString
                push 0
                call MessageBoxA
                                
                push 0
                call ExitProcess
                
;---------------
;tabela de importacao           
;---------------
section '.3' import data readable writeable
                
                library Kernel32,'Kernel32.dll'
                library User32,'User32.dll'
                
                import User32,MessageBoxA,'MessageBoxA'
                import Kernel32,ExitProcess,'ExitProcess'
    


The above code compiles without error or warning but it gives a GPF when I run it. I debugged it with Ollydbg to see what was wrong and I saw the following:

Code:

00402000 > $ 6A 00          PUSH 0
00402002   . 68 0F104000    PUSH silvio.0040100F                     ;  ASCII "Dumb Title"
00402007   . 68 00104000    PUSH silvio.00401000                     ;  ASCII "Hello world!"
0040200C   . 6A 00          PUSH 0
0040200E   . E8 5D100000    CALL silvio.00403070
00402013   . 6A 00          PUSH 0
00402015   . E8 74100000    CALL <&Kernel32.ExitProcess>

    


Whell the MessageBoxA api wasn't compiled correctly.
Is it a bug in fasm?
Post 12 May 2005, 12:50
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flaith



Joined: 07 Feb 2005
Posts: 122
Location: $300:20 58 FC 60 N 300G => Vietnam
flaith
try :

Code:
...
        start:
                push 0
                push DumbTitle
                push DumbString
                push 0
                call [MessageBoxA]              ; change to ptr MessageBoxA

                push 0
                call [ExitProcess]              ; here too
...
    

_________________
Je suis sur de 'rien', mais je ne suis pas sur du 'tout'.
Post 12 May 2005, 14:29
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Cthulhu



Joined: 12 May 2005
Posts: 29
Cthulhu
It didn't work... the result was the same Sad
Post 12 May 2005, 15:45
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flaith



Joined: 07 Feb 2005
Posts: 122
Location: $300:20 58 FC 60 N 300G => Vietnam
flaith
the whole code :

Code:
format PE GUI 4.0
entry start

include '%fasminc%\win32a.inc'

;---------------
;secao de dados
;---------------
section '.1' data readable writeable

        DumbString db "Hello world!",0
        DumbTitle db "Dumb Title",0

;---------------
;secao de codigo
;---------------
section '.2' code readable executable

        start:
                push 0
                push DumbTitle
                push DumbString
                push 0
                call [MessageBoxA]              ; change to ptr MessageBoxA

                push 0
                call [ExitProcess]              ; here too

;---------------
;tabela de importacao
;---------------
section '.3' import data readable writeable

                library Kernel32,'Kernel32.dll',\
                        User32,'User32.dll'                  ; changed here too

                import User32,MessageBoxA,'MessageBoxA'
                import Kernel32,ExitProcess,'ExitProcess'
    

_________________
Je suis sur de 'rien', mais je ne suis pas sur du 'tout'.
Post 12 May 2005, 15:51
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Cthulhu



Joined: 12 May 2005
Posts: 29
Cthulhu
Thanks friend!
Now it works Smile
Fasm looks great I think I'll move entirely to it.
Post 12 May 2005, 15:58
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flaith



Joined: 07 Feb 2005
Posts: 122
Location: $300:20 58 FC 60 N 300G => Vietnam
flaith
Cthulhu wrote:
Thanks friend!
Now it works Smile
Fasm looks great I think I'll move entirely to it.


me too Very Happy

_________________
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Post 12 May 2005, 16:07
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