uint32_t rng_num;
    asm volatile("movl $100, %ecxnt"
                 "__trng_cpu_ret:nt"
                 "rdrand %%eaxnt"
                 "jnc .__trng_cpu_endnt"
                 "loop __trng_cpu_retnt"
                 ".__trng_cpu_fail:nt"
                 "movl $0, %%eaxnt"
                 ".__trng_cpu_end:nt"
                 "retnt"
                  : "=r" (rng_num)
                  :
                  :"%eax");

mov ecx, 100   ;number of retries
retry:
    rdrand eax
    jnc .done      ;carry flag is clear on success
    loop retry
.fail:
    ;no random number available
.done:
    ;random number is is EAX