#------------------------------------------------------------------------------
#
# ArmRndr() for AArch64
#
# Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
#------------------------------------------------------------------------------

#include "ArmRng.h"

.text
.p2align 2
GCC_ASM_EXPORT(ArmRndr)

#/**
#  Generates a random number using RNDR.
#  Returns TRUE on success; FALSE on failure.
#
#  @param[out] Rand     Buffer pointer to store the 64-bit random value.
#
#  @retval TRUE         Random number generated successfully.
#  @retval FALSE        Failed to generate the random number.
#
#**/
#BOOLEAN
#EFIAPI
#ArmRndr (
#  OUT UINT64 *Rand
#  );
#
ASM_PFX(ArmRndr):
  AARCH64_BTI(c)
  mrs  x1, RNDR
  str  x1, [x0]
  cset x0, ne    // RNDR sets NZCV to 0b0100 on failure
  ret
