I wrote a simple program in assembly language which will simply display a message box in windows 7 32 bit
.386
.model flat, stdcall
option casemap :none
extrn MessageBoxA#16 : PROC
extrn ExitProcess#4 : PROC
.data
HelloWorld db "Welcome to SecurityTube.net!", 0
MsgTitle db "First MessageBox", 0
.code
start:
mov eax, 0
push eax
lea ebx, MsgTitle
push ebx
lea ebx, HelloWorld
push ebx
push eax
call MessageBoxA#16
push eax
call ExitProcess#4
end start
I use following command for assembling and linking
ml /c /coff helloworld.asm
link /subsystem:windows /defaultlib:kernel32.lib /defaultlib:user32.lib helloworld.obj
Program assembled perfectly. However, while linking, i got this error:
Microsoft (R) Incremental Linker Version 5.12.8078
Copyright (C) Microsoft Corp 1992-1998. All rights reserved.
LINK : fatal error LNK1104: cannot open file "kernel32.lib"
Why i am getting this error and how to mitigate it?
The command you're looking for is:
ml.exe helloworld.asm
/coff
/link
/subsystem:windows
/defaultlib:kernel32.lib
/defaultlib:user32.lib
/libpath:C:\...somewhere...
helloworld.obj
Note that instead of running ml first with the /c switch (which assembles only without linking), and then running link, I've just combined it all into a single command line. This will run MASM to assemble the code, and then immediately link it.
The magic sauce is the /link switch, which passes every argument that comes after it to the linker.
Notice the other new switch that you did not have: /libpath. This is the one that tells the linker where the LIB files can be found. They are part of the Windows SDK, so you'll need to locate that directory on your hard disk and substitute that path for C:\...somewhere.... The exact location differs depending on which version of the SDK you have installed and how you installed it (separately, or as part of Visual Studio). If you don't have the SDK, download it here for Windows 10, or for earlier versions. (Note that the latest version is sufficient; you do not need to download every version. It supports multi-targeting.)
The documentation for MASM is all available online, including a comprehensive listing of command line options. Same thing for the linker; its options are here.
An even easier solution would be to open the Visual Studio Command Prompt and do all of your assembling and linking from there. This actually runs a batch file that sets up the environment for you so that you don't have to worry about specifying the path to all of the required SDK files (headers, libraries, etc.). You'll find this in your Start menu, or manually run:
C:\Program Files (x86)\Microsoft Visual Studio x.x\VC\bin\vcvars32.bat
to set up a 32-bit build environment.
Did you check Visual Studio's directory structure and look for $(WindowsSdkDir)\lib to see if they exist?
If not install http://msdn.microsoft.com/en-us/windows/desktop/bg162891.aspx
Related
I've been using Visual Studio to assemble and link cpp programs that include masm (.asm) files. I want to be able to do this myself, on the command line. I used the ml.exe that Visual Studio provides to assemble my masm code (at Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\bin\Hostx86\x86\ml.exe).
However, when I try to compile my project with gcc main.cpp fib.obj -o main, I get an error saying that the .obj architecture does not match the target architecture (i386 architecture of input file 'fib.obj' is incompatible with i386:x86-64 output).
So my question is, simply, how do I compile this project?
What I've Tried
The two things that I've done to get different errors (which I think are more promising) are (1) to utilize the ml64 executable from ...\Hostx86\x64\ml64.exe or ...\Hostx64\x64\ml64.exe, and (2) to use the -m32 option for gcc.
ml64
Using ml64 I have been unable to assemble my masm code. with the following source file, ml64 spits out this response:
; int fib(int);
.386
.model flat, c
.code
fib proc uses ebx ecx, i:dword
mov eax, 0 ; current fib number
mov ebx, 1 ; next fib number
while_1:
cmp i, 0
jle while_1_end
; add eax -> ebx and mov previous ebx into eax
mov ecx, ebx ; store new current fib number
add ebx, eax ; sum previous fib numbers
mov eax, ecx ; set eax to current fib value
dec i
jmp while_1
while_1_end:
; the ith fib number is in eax
ret
fib endp
end
...\fib> ml64 fib.asm
Microsoft (R) Macro Assembler (x64) Version 14.29.30136.0
Copyright (C) Microsoft Corporation. All rights reserved.
Assembling: fib.asm
fib.asm(2) : error A2008:syntax error : .
fib.asm(3) : error A2008:syntax error : .
fib.asm(6) : error A2008:syntax error : ebx
fib.asm(24) : fatal error A1010:unmatched block nesting : fib
I presume that .386 isn't right for a x64 target, but removing it changes the error very little (it only removes the syntax error line 2).
I don't really want to use x64 assembly if it isn't the same as x32, but I'll use this solution if it works. I think my second option is more promising.
gcc -m32
I don't believe I can tell gcc to build to a 32-bit target because I don't have 32-bit versions of the libraries. When running gcc -m32 main.cpp fib.obj I get cannot find -lmingw32, cannot find -lgcc, cannot find -lgcc_ex, etc. Should I get these libraries, and if so, where do I find them? It seems a bit awful to download 32-bit libraries on my x64 computer just to assemble masm, and I don't think I should have to, seeing as Visual Studio is able to compile my project simply by setting the target to Win32.
Is there a different way of telling gcc to target 32-bit architecture, or are the libraries perhaps hidden in the Visual Studio files, or something else? I'm pretty sure that if I could get gcc to target x32, it would solve my problem, because Visual Studio targets x32, and when I change the target to x64 I get the same error I have been getting (module machine type 'x86' conflicts with target machine type 'x64').
I was trying to build an exe from asm file. The asm file looks like this:
global main
extern puts
section .data
msg:
db "Hello, world!",10,0
section .text
main:
sub rsp, 28h
mov rcx, msg
call puts
add rsp, 28h
ret
Then I assembled it using NASM and tried to link it using GCC. But it is showing this error.
> nasm -fwin64 asmtest.asm
> gcc asmtest.obj
asmtest.obj: file not recognized: File format not recognized
collect2.exe: error: ld returned 1 exit status
I am unable to figure out what is going on. My NASM version 2.14.02 and GCC version 8.1.0. I have followed this tutorial (at the bottom). I am doing this on my Windows 10 64-bit machine.
I have also seen this question, but it didn't help me.
You have installed mingw for 32 bit binaries. You need to install a version of mingw configured to make 64 bit binaries to compile and/or link 64 bit binaries.
I want to create a valid Win32 executable, that can be run as standalone application.
For example, this simple program:
bits 32
mov eax,1
ret
I compiled it using NASM with
nasm test.asm -o test.exe
Then I ran that program.
It started NTVDM and it told me "The NTVDM CPU encountered illegal instruction" and some technical details, probably dump, and registers.
So, I want to create a standalone Win32 application in assembly language. I don't want to create COM file, like in DOS.
[section] .text
global _start
_start:
mov eax, 1
ret
can be assembled like this:
nasm -fwin32 file.asm (this should give you file.obj)
and
link /subsystem:windows /entry:start file.obj
(or)
ld -e _start file.obj
whatever linker you choose should give you your .exe
At least Windows XP refuses to load an application that does not use any DLL files. I didn't test with Windows 7 up to now!
The reason is that there are no official interfaces but the DLLs that come with Windows and that a program that has neither inputs nor outputs makes no sense.
How do you compile assembly code using Visual Studio?
I want to compile and run an assembly source file in Visual Studio 2010.
I've created a Visual C++ project and inserted some assembly code in a file code.asm:
.586 ;Target processor. Use instructions for Pentium class machines
.MODEL FLAT, C ;Use the flat memory model. Use C calling conventions
.STACK ;Define a stack segment of 1KB (Not required for this example)
.DATA ;Create a near data segment. Local variables are declared after
;this directive (Not required for this example)
.CODE ;Indicates the start of a code segment.
clear PROC
xor eax, eax
xor ebx, ebx
ret
clear ENDP
END
However the problem is when you try and compile this, you get:
LINK : error LNK2001: unresolved external symbol _mainCRTStartup
I did go and enable the build customization masm.targets (right click project > Build Customizations..), but to no avail.
Sounds to me like the custom build rules for .asm files isn't enabled. Right-click the project, Custom Build Rules, tick "Microsoft Macro Assembler". With the "END clear" directive and disabling incremental linking I'm getting a clean build.
It's different starting from VS2010:
Right-click Project, Build customizations, tick "masm".
Right-click the .asm file, Properties, change Item Type to "Microsoft Macro Assembler".
Command line:
Compile the code with:
ml /c /Cx /coff code.asm
You get code.obj as the output.
Link with:
link code.obj /SUBSYSTEM:console /out:go.exe /entry:clear
You can now run go.exe.
Alternatively, do it all in one go with:
ml /Cx /coff code.asm /link /SUBSYSTEM:console /link /entry:clear
Visual Studio (not solved)
Visual Studio includes the MASM macro assembler. Smaller fragments of assembler code are often written in inline assembly in a C or C++ program.
To integrate an assembler file in a Visual Studio project, create a regular C/C++ project (command line or GUI), and just add a file ending in .asm to the list of source files.
To specify clear as the entry point, follow these instructions:
Open the project's Property Pages
dialog box. For details, see Setting
Visual C++ Project Properties.
Click the Linker folder.
Click the Advanced property page.
Modify the Entry Point property.
(It was taken from the Visual Studio documentation.)
I can confirm Hans Passant's instruction. In addition, according to this article, if you first add the "build customizations" masm checkbox, and then add the file, it will automatically be recognized as an assembler file. Furthermore, not specifying the entry point name in the END directive, but instead specifying it in the project settings also works for me.
here is how to compile nasm assembly source code with vs20xx:
"Excluded From Build" to "No"
"Item Type" to "Custom Build Tool"
Hit Apply
Custom Build Tool -> General -> Command Line:
c:\nasm\nasm -f win64 my_asm.asm
Custom Build Tool -> General -> Outputs:
my_asm.obj
call the function like this:
extern "C" int foo(void); // written in assembly!
https://www.cs.uaf.edu/2017/fall/cs301/reference/nasm_vs/
nasm tutorial:
http://cs.lmu.edu/~ray/notes/nasmtutorial/
The problem is that your assembly code is just a function. To compile and link, you need to have a start procedure just like Main in C/C++. You can specify the start symbol by specifying in your END directive. Like:
END clear
Or if you want, you can link the .obj file generated with the C/C++ generated .obj one.
How do you compile assembly code using Visual Studio?
I want to compile and run an assembly source file in Visual Studio 2010.
I've created a Visual C++ project and inserted some assembly code in a file code.asm:
.586 ;Target processor. Use instructions for Pentium class machines
.MODEL FLAT, C ;Use the flat memory model. Use C calling conventions
.STACK ;Define a stack segment of 1KB (Not required for this example)
.DATA ;Create a near data segment. Local variables are declared after
;this directive (Not required for this example)
.CODE ;Indicates the start of a code segment.
clear PROC
xor eax, eax
xor ebx, ebx
ret
clear ENDP
END
However the problem is when you try and compile this, you get:
LINK : error LNK2001: unresolved external symbol _mainCRTStartup
I did go and enable the build customization masm.targets (right click project > Build Customizations..), but to no avail.
Sounds to me like the custom build rules for .asm files isn't enabled. Right-click the project, Custom Build Rules, tick "Microsoft Macro Assembler". With the "END clear" directive and disabling incremental linking I'm getting a clean build.
It's different starting from VS2010:
Right-click Project, Build customizations, tick "masm".
Right-click the .asm file, Properties, change Item Type to "Microsoft Macro Assembler".
Command line:
Compile the code with:
ml /c /Cx /coff code.asm
You get code.obj as the output.
Link with:
link code.obj /SUBSYSTEM:console /out:go.exe /entry:clear
You can now run go.exe.
Alternatively, do it all in one go with:
ml /Cx /coff code.asm /link /SUBSYSTEM:console /link /entry:clear
Visual Studio (not solved)
Visual Studio includes the MASM macro assembler. Smaller fragments of assembler code are often written in inline assembly in a C or C++ program.
To integrate an assembler file in a Visual Studio project, create a regular C/C++ project (command line or GUI), and just add a file ending in .asm to the list of source files.
To specify clear as the entry point, follow these instructions:
Open the project's Property Pages
dialog box. For details, see Setting
Visual C++ Project Properties.
Click the Linker folder.
Click the Advanced property page.
Modify the Entry Point property.
(It was taken from the Visual Studio documentation.)
I can confirm Hans Passant's instruction. In addition, according to this article, if you first add the "build customizations" masm checkbox, and then add the file, it will automatically be recognized as an assembler file. Furthermore, not specifying the entry point name in the END directive, but instead specifying it in the project settings also works for me.
here is how to compile nasm assembly source code with vs20xx:
"Excluded From Build" to "No"
"Item Type" to "Custom Build Tool"
Hit Apply
Custom Build Tool -> General -> Command Line:
c:\nasm\nasm -f win64 my_asm.asm
Custom Build Tool -> General -> Outputs:
my_asm.obj
call the function like this:
extern "C" int foo(void); // written in assembly!
https://www.cs.uaf.edu/2017/fall/cs301/reference/nasm_vs/
nasm tutorial:
http://cs.lmu.edu/~ray/notes/nasmtutorial/
The problem is that your assembly code is just a function. To compile and link, you need to have a start procedure just like Main in C/C++. You can specify the start symbol by specifying in your END directive. Like:
END clear
Or if you want, you can link the .obj file generated with the C/C++ generated .obj one.