rndr

Random Number

RNDR <Xt>

Reads a random number from hardware entropy source.

Details

Reads a 64-bit random number from the system's hardware entropy source and writes it to Xt. This instruction is AArch64-only and requires the FEAT_RNG extension. It does not modify condition flags and may set the C flag to indicate failure (entropy unavailable), depending on implementation.

Pseudocode Operation

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

Example

RNDR x3

Encoding

Binary Layout
11010101001
00011
0011
0010
010
Rt
 
Format System
Opcode 0xD53B2400
Extension FEAT_RNG

Operands

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