sys_write in betterC doesn't write anything

[Basile B.]

On Saturday, 3 February 2018 at 15:30:10 UTC, Basile B. wrote:
> compiles with -betterC -m32
>
> module runnable;
>
> __gshared static msg = "betterC";
> __gshared static len = 7;
>
> extern(C) int main(int argc, char** args)
> {
>     asm
>     {
>         naked;
>         mov EDX, len ;//message length
>         mov ECX, msg ;//message to write
>         mov EBX, 1   ;//file descriptor (stdout)
>         mov EAX, 4   ;//system call number (sys_write)
>         int 0x80     ;//call kernel
>
>         mov EBX, 0   ;//process' exit code
>         mov EAX, 1   ;//system call number (sys_exit)
>         int 0x80     ;//call kernel - this interrupt won't 
> return
>     }
> }
>
> nothing is printed. Could this work ?

okay solved:



module runnable;

__gshared static msg = "betterC\n";
__gshared static len = 8;

extern(C) int main(int argc, char** args)
{
     asm
     {
         naked;
         mov EDX, len ;//message length
         mov ECX, [msg + 4] ;//message to write
         mov EBX, 1   ;//file descriptor (stdout)
         mov EAX, 4   ;//system call number (sys_write)
         int 0x80     ;//call kernel

         mov EBX, 0   ;//process' exit code
         mov EAX, 1   ;//system call number (sys_exit)
         int 0x80     ;//call kernel - this interrupt won't return
     }
}

the pointer to the string data is 4 bytes later...