Re: [Qemu-devel] question about syscall

[Mulyadi Santosa <mulyadi.santosa@gmail.com>]

Hi

On Tue, Feb 10, 2009 at 2:23 AM, Antonio Ricci <ricciantonio@gmail.com> wrote:
> Hi Muladi,
>
> some times ago someone said me to do something like this:
>
> /****************************************************/
> a piece of code handling interrupt in translate.c:
> case 0xcd: /* int N */
>
>       val = ldub_code(s->pc++);
>       /* asia: start */
>       if (val == 0x80){
>         gen_op_handle_syscall();
>         break;
>       }
>
>       if (s->vm86 && s->iopl != 3) {
>           gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
>
>       } else {
>           gen_interrupt(s, val, pc_start - s->cs_base, s->pc - s->cs_base);
>       }
>       break;
>
> /*********************************************************/
>
>
> I can't understand why I have to intercept the case 0xcd. Can you explain
> me?

My guess is, 0xcd is the opcode of "int" instruction. Try to check
Intel instruction manual....

regards,

Mulyadi.