We begin in the name of the kindful and merciful Almighty Allah. Assembly language is a programming language like other computer languages. It speaks very close to the language of the processor, the machine language. It allows us to use the functions of latest processors which are not yet supported by the compilers.
Assembly language is used in writing driver programs for various devices in the computer system, like graphics card, WiFi card, finger scanner etc. To start assembly programming in microsoft windows, we will need to install two tools. It will install some old versions of NASM along with gcc compiler.
After installation, these tools can only be used from their installation directories. We have to use these tools outside of there installation folders. For that we need to tell windows where these are installed. We have to make changes to system settings. Alternatively, we can use commands. Type the following command and press OK. This will open the system window as shown below. By clicking new, an empty row is highlighted in below.
Here we will copy the address of the folder where NASM is installed. Copy the folder address by clicking at the address bar. Similarly track the folder where MinGW-w64 was installed.
Do to bin subfolder. Observe that gcc. It will return an error. The good thing is, this is not the error that, commands are not recognized. Rather, it is commands are not properly executed. Create a new folder where we will be saving our assembly language code. I have created a folder in my c: drive by the name of COAL. Open the command line window. Change to the drive where your working folder is saved. See which files are here by typing the directory dir command.
Here -g flag is used to add the debug information in assembled output. This is also known as object code. Reminding myself of that, I chose to go with Netwide Assembler. In all programs in this blog, I will be using version 2. You can download for Windows here. I decided to go with gcc, simply for the sake of trust on the community. I use version 5. Either way, calling the kernel directly in Windows seems to be not the way forward.
If we cannot directly call the kernel, then what options are available to us? The obvious choice is C runtime libraries. And why not the trusted printf? This time, we call printf. Our aim was to program for Win32, not call a C routine.
Like in the previous examples, you have to assemble, link and run. However, let me introduce another way to do all 3 in one line:. Again, knowing how a Win32 function is mangled, or decorated after compiling seems like far too much to expect at this level. This will force us to so something out of the ordinary. What this does is to import function names directly as defined in the DLLs, thereby freeing us from having to mangle the function names ourselves.
Unfortunately, there is nothing we can do about this, so we will use a workaround. We are going to use -fobj instead of -fwin At least this will give us an obj file. This means that ld which is the linker under the hood of gcc did not like our obj format. We did indeed supply a wrong file format. What we should now do is to find a less restricting linker that will overlook this fact.
Viewed 88 times. Improve this question. Peter Cordes k 41 41 gold badges silver badges bronze badges. Daros Daros 2 2 silver badges 9 9 bronze badges. It looks for as many extra args as the format string first arg makes it look for. If there were more, yes it would look on the stack, same as always.
Add a comment. Active Oldest Votes. Improve this answer. So if there are no format specifiers printf "know" that there is only one parameter as in my example, right? Yes, when there are no format specifiers printf will not search for additional parameters.
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