NSA - RDRAND

I've been reading some stuff about all this mess and i've decided to check out the implementation of RDRand. I found this "we are architecturally guaranteed a reseed" a bit confusing , maybe someone with more experience in random number generation and encryption makes some sense out of it .. if you check the code there's a ASM call if the feature is supported and that's it. I found it curious

NSA - RDRAND
lxr.free-electrons.com

That's just the code in Linux that calls RDRAND.

Here is the actual instruction in VHDL:

  --
  -- copyright NSA, Top Secret//UMBRA
  -- 

  entity RDRAND is
  port(	
    RND: out rnd_long
  );
  end RDRAND;  

  architecture RDRAND of x64_op is
  begin
      
    RND