rndrrs

Random Number Reseed

RNDRRS <Xt>

Reads a random number and requests reseed.

Details

Reads a 64-bit random number from the hardware entropy source, writes it to Xt, and requests a reseed of the entropy generator. This instruction is AArch64-only and requires the FEAT_RNG extension. It may set the C flag to indicate entropy availability, similar to RNDR.

Pseudocode Operation

Xt ← HardwareRandomNumber()
RequestReseed(entropy_generator)
if entropy_available then
  C ← 0
else
  C ← 1
end if

Example

RNDRRS x3

Encoding

Binary Layout
11010101001
00011
0011
0010
011
Rt
 
Format System
Opcode 0xD53B2600
Extension FEAT_RNG

Operands

  • Xt
    Transfer 64-bit integer register (load/store)