From: bc@nospicedham.freeuk.com   
      
   On 26/11/2019 06:12, Xavier Maillard wrote:   
   > Hello,   
   >   
   > I am just starting to learn writing some fun progs in asm.   
   >   
   > I just jotted down some instructions, assembled it and linked it.   
   > Running it just segfault.   
   >   
   > The question is: why ? :)   
   >   
   > The program is just this:   
   >   
   > .section .data   
   >   
   > .section .text   
   > .globl _start   
   > _start:   
   >   
   > movl $1, %eax   
   > movl $0, %ebx   
   > int $0x80   
   >   
   > As you can see, it just does *nothing*   
   Syscall #1 appears to do 'exit', so it /ought/ to do nothing!   
      
   Are you saying it crashes instead of gracefully exiting?   
      
   Is your system 64 bits? If so you might try using rax and rbx instead of   
   eax and ebx. However I don't know whether the 64-bit set of syscalls are   
   the same (one set I saw appeared to be different from the 32-bit ones.   
   eg call #1 does sys_write).   
      
   (I know nothing about Linux assembly coding, it just looked intriguing.)   
      
   If you can't get anywhere, try starting from C and write the simplest   
   program. Compile it like this:   
      
        gcc -S prog.c   
      
   to get the assembly output in prog.s, which can also be assembled and   
   linked by gcc (which will invoke as and ld, or you can do that yourself):   
      
       gcc prog.s -oprog   
      
   Now you can play with the ASM instructions in prog.s, but starting from   
   something that works.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)