small hello world again

[sinsi]

jj, the macros in fasm are much more complex.

Code Select Expand


; example of simplified Windows programming using complex macro features
include 'win32ax.inc' ; you can simply switch between win32ax, win32wx, win64ax and win64wx here
.code
  start:
invoke MessageBox,HWND_DESKTOP,"Hi! I'm the example program!",invoke GetCommandLine,MB_OK
invoke ExitProcess,0
.end start

Here's how to import functions the raw way

Code Select Expand


section '.idata' import data readable writeable

  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

and the easy way

Code Select Expand


; import data in any section
data import
library kernel32,'KERNEL32.DLL',\
user32,'USER32.DLL',\
winmm,'WINMM.DLL'
import kernel32,\
ExitProcess,'ExitProcess'
import user32,\
MessageBoxA,'MessageBoxA'
import winmm,\
mciSendString,'mciSendStringA'
end data


No need for a linker.

[jj2007]

jj, the macros in fasm are much more complex.

So a simple mov ecx, len(esi) is not possible? I.e. the function form of macros doesn't exist in FASM?

[Mikl__]

jj2007,
and how you can know  the length of the string pointed to by the register ESI before compilation?

[jj2007]

jj2007,
and how you can know  the length of the string pointed to by the register ESI before compilation?

Mysteries of MASM :P

Run this with a debugger:

Code Select Expand

include \masm32\include\masm32rt.inc

.code
start:
  mov esi, chr$("Hello World")
  MsgBox 0, str$(len(esi)), "Bytes:", MB_OK
  exit
end start

[hutch--]

Mikl__,

Fixed length string lengths are known at assembly time, they do not necessarily need runtime support, even though runtime support will deliver the same answer. The pre-processor in MASM is a bad mannered old pig but it is powerful.

[StarsInTheSky]

Just an update on my struggle to understand #2 question...

First this Quickedit is a wonderful, I love the way you easily can change all menues :D

So I am using the makeit.bat option, inside my makeit.bat I put the following:

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set PATH=%PATH%;C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE;C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin
Set filepath=%1
For %%A in (%filepath%) do (
    Set Folder=%%~dpA
    Set fileName=%%~nxA
)

nmake Name=%filename%
pause


So I am getting the filename from Quickedit and I pass it to nmake. In my MAKEFILE I have:

Code Select Expand


$(NAME).exe: $(NAME).obj
        "\masm32\bin\poLink.exe /SUBSYSTEM:WINDOWS /LIBPATH:c:\masm32\lib /MERGE:.rdata=.text /MERGE:.data=.text /OPT:REF /OPT:NOWIN98 $(NAME).obj
$(NAME).obj: $(NAME).asm
        "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin\ml.exe" /c /coff /Cp $(NAME).asm


But the libpath is not working for my code. The calls to MessageBoxA@16 and ExitProcess@4 gives me errors.
So not been succesful in replacing the /defaultlib:C:\masm32\lib\kernel32.lib /defaultlib:C:\masm32\lib\user32.lib yet.
I'm missing something...

EDIT: I got #2 working. Just by including the inc files and the libs, instead of the external declarations, the calls worked. i don't need to write it with the invoke syntax.  :icon_mrgreen: In fact Mikl has given me hints about this with the codes. I can use my external declarations with the libs and omit the includes if I like to. Thanks again Mikl  :t

[StarsInTheSky]

For my particular question about #1, I have only found others having problem with the /ALIGN argument as well and no solution. Abandoning Link for polink, I got my hello world to 1K, and I've read that 1 K (1024 bytes) is the lowest you can get a working exe file on win 7 x64. Could someone confirm? Is there a theory behind that? Is it related to that the memory manager handles memory at 1K chunks in x64? I tried to run the upx packer on my 1K messagebox, and indeed it throws this error: upx: messageboxa2e.exe: NotCompressibleException

For learning PE I found this thread:
http://board.flatassembler.net/topic.php?t=1309

Is there a MASM syntax equivalent?

[jj2007]

I've read that 1 K (1024 bytes) is the lowest you can get a working exe file on win 7 x64. Could someone confirm?

You should not believe all that stuff that people post on the Internet. 929 bytes is possible  8)

[StarsInTheSky]

Hehe dos is dead, long live windows. the dos stub has become the data section  Thanks JJ

[Mikl__]

Hi, StarsInTheSky !
For learning PE see

• http://www.cyberforum.ru/post3945127.html
• http://www.cyberforum.ru/post3946211.html
• http://www.cyberforum.ru/post4075465.html

Or Iczelion's PE Tutorials

• Overview of PE File Format
• Detecting a Valid PE File
• File Header
• Optional Header
• Section Table
• Import Table
• Export Table

or Microsoft Portable Executable and Common Object File Format Specification
or PE a windows executable walkthrough

[K_F]

Hey Stars.. sh.tload of stuff to go through... 

Don't worry, we all had to do the same.. takes a bit of time but you'll get there.
.. and when it happens.. there's no looking back !!  :t