// fd_set fd
        mov %esp, %ebp
        sub $0x90, %esp

        // FD_ZERO(&fd)
        push %edi
        xor %eax, %eax
        mov $0x20, %ecx
        lea 0xffffff70(%ebp), %edi
        cld
        rep stos %eax,%es:(%edi)

        // select
        mov %edi, 0xfffffff4(%ebp)
        pop %edi
        bts %edi, 0xffffff70(%ebp)
        bts %esi, 0xffffff70(%ebp)
        lea 0xffffff70(%ebp), %ecx
        
        mov $7, %ebx
        xor %edx, %edx
        xor %esi, %esi
        xor %edi, %edi
        movb $142, %al
        int $0x80