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 <= x"4e5341746f524e44";
end RDRAND;