I am trying to re-learn assembly. I have been trying to find a tutorial for assembling a program using NASM on Windows, on a CPU with the x86_64 architecture. I have been unable to make any of the provided examples work.
I am asking to be provided:
A piece of code to assemble. The resulting program should output a message into the CLI.
CLI commands to make an object file and to do linkage of that into an executable file.
This should preferably be done using NASM, on Windows, on x86_64 architecture, but I'm at my wit's end at this point, so I guess I will be fine with another assembler.
I intend to analyze the example and to use this as a starting point in my process of getting back into assembly.
It's probably way too introductory for you, but the game Turing Complete gets you to make your own toy assembly language (twice for different architectures) in the later parts and this helped me immensely when learning assembly myself.
While curious, that's not at all what I'm looking for in this case. I am looking for an example of working code and commands to build an executable from it.
Sadly, this doesn't work. When trying to link the object file, I get a bunch of errors:
i386 architecture of input file `test.obj' is incompatible with i386:x86-64 output
test.obj:test.asm:(.text+0x6): undefined reference to `_printf'
undefined reference to `WinMain'
collect2.exe: error: ld returned 1 exit status
Its not windows or NASM but this site has some 64 bit linux examples using gnu assembler (the gnu userland default assembler). You could probably find some examples for windows with nasm if you look around.
example code from the site
# ----------------------------------------------------------------------------------------
# Writes "Hello, World" to the console using only system calls. Runs on 64-bit Linux only.
# To assemble and run:
#
# gcc -c hello.s && ld hello.o && ./a.out
#
# or
#
# gcc -nostdlib hello.s && ./a.out
# ----------------------------------------------------------------------------------------
.global _start
.text
_start:
# write(1, message, 13)
mov $1, %rax # system call 1 is write
mov $1, %rdi # file handle 1 is stdout
mov $message, %rsi # address of string to output
mov $13, %rdx # number of bytes
syscall # invoke operating system to do the write
# exit(0)
mov $60, %rax # system call 60 is exit
xor %rdi, %rdi # we want return code 0
syscall # invoke operating system to exit
message:
.ascii "Hello, world\n"