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> Windows > My first PE program that could (but don't) |
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bitshifter 19 May 2009, 23:10
You are trying to use a word pointer, it needs dword pointer
Use 32 bit instructions for Win32 PE Needs much other work to be ready. Start looking at fasm examples. Its youre lucky day (i had nothing better to do) Code: format PE GUI 4.0 entry start section '.text' code readable executable start: mov ax,word[_message] mov bx,word[_compare] mov edi,_yes cmp ax,bx je finish mov edi,_no finish: push 0x00040040 ; MB_OK | MB_TOPMOST | MB_ICONINFORMATION push _caption push edi push 0 call [MessageBoxA] push 0 call [ExitProcess] section '.data' data readable ;writeable _caption db 'result',0 _message db 'aa' _compare db 'aa' _yes db 'same',0 _no db 'not the same',0 section '.idata' import data readable dd 0,0,0,rva kernel_name,rva kernel_table dd 0,0,0,rva user_name,rva user_table dd 0,0,0,0,0 kernel_table: ExitProcess dd rva _ExitProcess dd 0 user_table: MessageBoxA dd rva _MessageBoxA dd 0 kernel_name db 'kernel32.dll',0 user_name db 'user32.dll',0 _ExitProcess dw 0 db 'ExitProcess',0 _MessageBoxA dw 0 db 'MessageBoxA',0 section '.reloc' fixups data readable discardable _________________ Coding a 3D game engine with fasm is like trying to eat an elephant, you just have to keep focused and take it one 'byte' at a time. |
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19 May 2009, 23:10 |
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Esaam 19 May 2009, 23:54
Thank you very much as all the example I could find where using cinvokes and I would rather not use them for now.
However, I wanted to use console output. Which again is called through cinvoke in the examples I found. |
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19 May 2009, 23:54 |
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Borsuc 20 May 2009, 00:57
All you have to do is manually "push" the function's arguments then, from right to left (i.e push the right-most first). Then call [WriteFile] or whatever with the console handle.
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20 May 2009, 00:57 |
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bitshifter 20 May 2009, 06:36
How to get a console up and running in Windoze...
http://board.flatassembler.net/topic.php?t=10049 And like Borsuc said, something using invoke macro... Code: invoke MyTask,[value1],[value2] Can use no macro to do same thing... Code: push [value2] push [value1] call MyTask Or even for imported funcs... Code: push [value2] push [value1] call [ImpTask] _________________ Coding a 3D game engine with fasm is like trying to eat an elephant, you just have to keep focused and take it one 'byte' at a time. |
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20 May 2009, 06:36 |
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DOS386 21 May 2009, 13:48
You may NEVER use int 21h in a Win32 PE (might work in a DOS PE if someone insists, though). Your org 100h is NOT a Win32 executable, even if it "seems to work". You can use 16-bit instructions in a Win32 PE, but 32-bit is more efficient.
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21 May 2009, 13:48 |
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Japheth 22 May 2009, 16:27
DOS386 wrote: You may NEVER use int 21h in a Win32 PE. This is "usually" true only. Here's a FASM sample how to use INT 21h in a Win32 PE: Code: format PE ;--- running DOS in Win32 szHello db "Hello world!",13,10,'$' entry realstart start: mov edx,szHello mov ah,09h int 21h mov ax,4c00h int 21h myexc: ;proc c pReport:dword, pFrame:dword, pContext:dword pushad mov ebp,esp pReport equ [ebp+9*4] pFrame equ [ebp+10*4] pContext equ [ebp+11*4] STD_OUTPUT_HANDLE equ -11 rEdx equ 0A8h rEax equ 0B0h rEip equ 0B8h rEfl equ 0C0h mov ebx, pReport mov edi, pContext mov edx, [edi+rEip] cmp word [edx], 021CDh jnz noint21 mov al,[edi+rEax+1] cmp al,09 jnz isnt09 push STD_OUTPUT_HANDLE call [GetStdHandle] mov ebx, eax mov esi,[edi+rEdx] nextitem: cmp byte [esi], '$' jz stringout_done push 0 mov edx, esp push 0 push edx push 1 push esi push ebx call [WriteConsole] pop edx inc esi jmp nextitem stringout_done: and byte [edi+rEfl],0FEh jmp int21done isnt09: cmp al,4ch jnz int21done movzx eax,byte [edi+rEax] push eax call [ExitProcess] int21done: add dword [edi+rEip], 2 mov eax,0 ;0=continue execution jmp doneexc noint21: mov eax,1 doneexc: mov [esp+28],eax popad ret realstart: xor edx,edx push myexc push dword [fs:0] mov [fs:edx],esp call start push eax call [ExitProcess] section '.idata' import data readable writeable dd 0,0,0,RVA kernel_name,RVA kernel_table dd 0,0,0,0,0 kernel_table: ExitProcess dd RVA _ExitProcess GetStdHandle dd RVA _GetStdHandle WriteConsole dd RVA _WriteConsole dd 0 kernel_name db 'KERNEL32.DLL',0 _ExitProcess dw 0 db 'ExitProcess',0 _GetStdHandle dw 0 db 'GetStdHandle',0 _WriteConsole dw 0 db 'WriteConsoleA',0 The original sample was in Masm and posted in the Masm32 forum some months ago. |
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22 May 2009, 16:27 |
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DOS386 23 May 2009, 09:07
Japheth wrote:
Yeah ... this is great  I've been searching for such an example and it even seems to work (on XP, later will test on ME also)
Still, this is a very exotic hack, for beginners the rule persists: use PE examples and avoid int 21h (and INT instruction at all), org 100h and accessing segment registers  |
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23 May 2009, 09:07 |
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LiuGuoHua(Chinese) 03 Dec 2009, 14:36
To Japheth:
A very good trick to emulate DOS interruption! But I don't thinks it's a good example for beginner, maybe they will get a wrong conclusion that it is possible to call "int 21" on win32. |
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03 Dec 2009, 14:36 |
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DOS386 06 Dec 2009, 22:55
> But I don't thinks it's a good example for beginner
Indeed, it's cool but not for a beginner. Also, one shouldn't ASS'ume that you can "use" segment registers in Win32 code (except, of course, for exceptions). > ;--- running DOS in Win32 It doesn't work in ME  |
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06 Dec 2009, 22:55 |
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