Re: [LIP] syscall simulation!

On Thu, Feb 17, 2005 at 08:01:24PM -0800, sanjay panchal wrote:
> Here's the code snippet. 
> main()
> {
>     char hello[]="hello world\n";
>     __asm__ __volatile(
>          "xorl %%eax,%%eax\n\t"
>          "movl $4,%%eax\n\t"      /*$4 SYS_write*/    
>          "xorl %%ebx,%%ebx\n\t"
>          "movl $1,%%ebx\n\t"      /*$1 fd for stdout*/
>          "movl %0,%%ecx\n\t"      /*string */ 
>          "movl $12,%%edx\n\t"     /*strlength*/
>          "int $0x80\n\t"
>          ::"g" (hello)
>     );
>         printf("\n");
> }

Your xors are superfluous and the real issue is that ecx is 0 when you call
int 0x80. Try:

main()
{
    char hello[]="hello world\n";
    __asm__ __volatile(
         "movl $4,%%eax\n\t"      /*$4 SYS_write*/
         "movl $1,%%ebx\n\t"      /*$1 fd for stdout*/
         "movl $12,%%edx\n\t"     /*strlength*/
         "int $0x80\n\t"
         :: "c" (hello)
    );
        printf("\n");
}

	-Arun


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