Windows system calls assembly

How to write hello world in assembler under Windows? All answers that give code give only code for outdated windows versions bit , except one. The one answer that works for 64 bit I tried, but the command to link the object file gave an error for me, that the system could not find the path specified. This site does not contain any code, which is what I need.

Also, I am trying to write the Hello World program in nasm. The question actually contains code for a hello world program, but when executed under cygwin on windows 10 my device , I get a segmentation fault. Why does Windows64 use a different calling convention from all other OSes on x?

I have tried disassembling a C Hello World Program with objdump -d, but this calls printf, a prebuilt C function, and I am trying to avoid using external functions. I have tried other external functions such as Messagebox , but they return errors because something does not recognize the functions. Also, I am trying not to use any extern functions if possible, only syscall, sysenter, or interrupts. Problem: Does not assemble properly; says "test. I just need an example of a hello world assembly program that works on bit Windows If it is not possible to print a string to the console without using external functions, an example of a program that uses external functions and works on bit Windows 10 would be nice.

Internally Windows uses either interrupts or system calls. However they are not officially documented and they may change anytime Microsoft wants to change them :. Only a few. A certain sequence for example mov rax, 5 , syscall might have the meaning "print out a text" before a Windows update and Microsoft might change the meaning of this sequence to "delete a file" after a Windows update. To do this Microsoft simply has to replace the kernel and the.

The only way to call Windows operating system functions in a way that it is guaranteed that your program is still working after the next Windows update is to call the functions in the. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Assembly Syscalls in bit Windows Ask Question. Asked 3 years, 8 months ago. Active 3 years, 8 months ago.

Viewed 11k times. StackOverflow links that didn't work for me: bit windows assembler As far as I know, nasm does support bit windows using the -f win64 extension.

Also, the answers have nothing to do with how to write an actual program in assembly on x64 bit windows How to write hello world in assembler under Windows? CODE: Attempt 1: section. Attempt 2: section. Attempt 4: section. I heard that syscalls in windows have far different addresses than those in linux. Eagterrian Knight Eagterrian Knight 1 1 gold badge 2 2 silver badges 11 11 bronze badges. Attempt 2 is 16bit DOS code, will not work as windows executable, and mov al,imm8 instruction can contain only single 8 bit immediate value, so you have to pick if you want number '!

Attemp 3: unless you specify with some label where the code starts, it may start at the beginning of. Is there a special flag to set with ld to specify where the start of the program is? This question looks a little like this. Is it possible? I looked at this table , but I don't really understand the names of the syscalls. Any help is welcome. Really, there is not that big an overhead with targeting public, documented functions, and you get Microsoft's guarantee that your program will work with future versions of Windows provided you use the API correctly.

For that reason, I won't provide you with the answer you want. I find this line of reasoning problematic and I don't want to act as an enabler for these kinds of development practices, especially as there is no practical benefit to using syscalls for console tasks.

If someone wants to know how to use low-level syscalls in Windows then please post a new question, suitably framed, and I'll gladly answer it. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more.

Windows system calls [duplicate] Ask Question. Asked 8 years ago. Active 2 years, 5 months ago. Viewed 21k times. DiscobarMolokai DiscobarMolokai 2 2 gold badges 5 5 silver badges 20 20 bronze badges.

Also, int 0x80 on Linux is the slow legacy way to invoke the bit ABI. The recommended way is to call into the VDSO so it can use sysenter for better performance. Add a comment. Active Oldest Votes. Dai Dai k 24 24 gold badges silver badges bronze badges. Strictly speaking, using that library this way isn't supported that I know of but it's a widespread practice.

It should certainly be good enough for your scenario.