MdePkg/BaseRngLib: Add support for ARMv8.5 RNG instructions

Make BaseRngLib more generic by moving x86-specific functionality into
'Rand' and adding files under 'AArch64' to support the optional ARMv8.5
RNG instruction RNDR that is a part of FEAT_RNG.

Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

MdePkg/Library/BaseRngLib/AArch64/ArmReadIdIsar0.S

@@ -0,0 +1,31 @@
+#------------------------------------------------------------------------------
+#
+# ArmReadIdIsar0() for AArch64
+#
+# Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#------------------------------------------------------------------------------
+
+.text
+.p2align 2
+GCC_ASM_EXPORT(ArmReadIdIsar0)
+
+#/**
+#  Reads the ID_AA64ISAR0 Register.
+#
+#  @return The contents of the ID_AA64ISAR0 register.
+#
+#**/
+#UINT64
+#EFIAPI
+#ArmReadIdIsar0 (
+#  VOID
+#  );
+#
+ASM_PFX(ArmReadIdIsar0):
+  mrs  x0, id_aa64isar0_el1 // Read ID_AA64ISAR0 Register
+  ret
+
+

MdePkg/Library/BaseRngLib/AArch64/ArmReadIdIsar0.asm

@@ -0,0 +1,30 @@
+;------------------------------------------------------------------------------
+;
+; ArmReadIdIsar0() for AArch64
+;
+; Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+;
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+  EXPORT ArmReadIdIsar0
+  AREA BaseLib_LowLevel, CODE, READONLY
+
+;/**
+;  Reads the ID_AA64ISAR0 Register.
+;
+; @return The contents of the ID_AA64ISAR0 register.
+;
+;**/
+;UINT64
+;EFIAPI
+;ArmReadIdIsar0 (
+;  VOID
+;  );
+;
+ArmReadIdIsar0
+  mrs  x0, id_aa64isar0_el1 // Read ID_AA64ISAR0 Register
+  ret
+
+  END

MdePkg/Library/BaseRngLib/AArch64/ArmRng.S

@@ -0,0 +1,37 @@
+#------------------------------------------------------------------------------
+#
+# ArmRndr() for AArch64
+#
+# Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#------------------------------------------------------------------------------
+
+#include "BaseRngLibInternals.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):
+  mrs  x1, RNDR
+  str  x1, [x0]
+  cset x0, ne    // RNDR sets NZCV to 0b0100 on failure
+  ret

MdePkg/Library/BaseRngLib/AArch64/ArmRng.asm

@@ -0,0 +1,39 @@
+;------------------------------------------------------------------------------
+;
+; ArmRndr() for AArch64
+;
+; Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+;
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+#include "BaseRngLibInternals.h"
+
+  EXPORT ArmRndr
+  AREA BaseLib_LowLevel, CODE, READONLY
+
+
+;/**
+;  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
+;  );
+;
+ArmRndr
+  mrs  x1, RNDR
+  str  x1, [x0]
+  cset x0, ne    // RNDR sets NZCV to 0b0100 on failure
+  ret
+
+  END

MdePkg/Library/BaseRngLib/AArch64/ArmRng.h

@@ -0,0 +1,42 @@
+/** @file
+  Random number generator service that uses the RNDR instruction
+  to provide pseudorandom numbers.
+
+  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef ARM_RNG_H_
+#define ARM_RNG_H_
+
+/**
+  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
+  );
+
+/**
+  Reads the ID_AA64ISAR0 Register.
+
+  @return The contents of the ID_AA64ISAR0 register.
+
+**/
+UINT64
+EFIAPI
+ArmReadIdIsar0 (
+  VOID
+  );
+
+#endif /* ARM_RNG_H_ */

MdePkg/Library/BaseRngLib/AArch64/Rndr.c

@@ -0,0 +1,139 @@
+/** @file
+  Random number generator service that uses the RNDR instruction
+  to provide pseudorandom numbers.
+
+  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/RngLib.h>
+
+#include "ArmRng.h"
+#include "BaseRngLibInternals.h"
+
+STATIC BOOLEAN mRndrSupported;
+
+//
+// Bit mask used to determine if RNDR instruction is supported.
+//
+#define RNDR_MASK                  ((UINT64)MAX_UINT16 << 60U)
+
+/**
+  The constructor function checks whether or not RNDR instruction is supported
+  by the host hardware.
+
+  The constructor function checks whether or not RNDR instruction is supported.
+  It will ASSERT() if RNDR instruction is not supported.
+  It will always return EFI_SUCCESS.
+
+  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+BaseRngLibConstructor (
+  VOID
+  )
+{
+  UINT64 Isar0;
+  //
+  // Determine RNDR support by examining bits 63:60 of the ISAR0 register returned by
+  // MSR. A non-zero value indicates that the processor supports the RNDR instruction.
+  //
+  Isar0 = ArmReadIdIsar0 ();
+  ASSERT ((Isar0 & RNDR_MASK) != 0);
+
+  mRndrSupported = ((Isar0 & RNDR_MASK) != 0);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Generates a 16-bit random number.
+
+  @param[out] Rand     Buffer pointer to store the 16-bit random value.
+
+  @retval TRUE         Random number generated successfully.
+  @retval FALSE        Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+ArchGetRandomNumber16 (
+  OUT     UINT16                    *Rand
+  )
+{
+  UINT64 Rand64;
+
+  if (ArchGetRandomNumber64 (&Rand64)) {
+    *Rand = Rand64 & MAX_UINT16;
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
+/**
+  Generates a 32-bit random number.
+
+  @param[out] Rand     Buffer pointer to store the 32-bit random value.
+
+  @retval TRUE         Random number generated successfully.
+  @retval FALSE        Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+ArchGetRandomNumber32 (
+  OUT     UINT32                    *Rand
+  )
+{
+  UINT64 Rand64;
+
+  if (ArchGetRandomNumber64 (&Rand64)) {
+    *Rand = Rand64 & MAX_UINT32;
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
+/**
+  Generates a 64-bit random number.
+
+  @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
+ArchGetRandomNumber64 (
+  OUT     UINT64                    *Rand
+  )
+{
+  return ArmRndr (Rand);
+}
+
+/**
+  Checks whether RNDR is supported.
+
+  @retval TRUE         RNDR is supported.
+  @retval FALSE        RNDR is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+ArchIsRngSupported (
+  VOID
+  )
+{
+  return mRndrSupported;
+}

MdePkg/Library/BaseRngLib/BaseRng.c

@@ -1,8 +1,10 @@
 /** @file
-  Random number generator services that uses RdRand instruction access
+  Random number generator services that uses CPU RNG instructions to
-  to provide high-quality random numbers.
+  provide random numbers.
 
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
 Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -10,46 +12,15 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
 
-//
+#include "BaseRngLibInternals.h"
-// Bit mask used to determine if RdRand instruction is supported.
-//
-#define RDRAND_MASK                  BIT30
 
 //
 // Limited retry number when valid random data is returned.
 // Uses the recommended value defined in Section 7.3.17 of "Intel 64 and IA-32
-// Architectures Software Developer's Mannual".
+// Architectures Software Developer's Manual".
 //
-#define RDRAND_RETRY_LIMIT           10
+#define GETRANDOM_RETRY_LIMIT           10
 
-/**
-  The constructor function checks whether or not RDRAND instruction is supported
-  by the host hardware.
-
-  The constructor function checks whether or not RDRAND instruction is supported.
-  It will ASSERT() if RDRAND instruction is not supported.
-  It will always return RETURN_SUCCESS.
-
-  @retval RETURN_SUCCESS   The constructor always returns EFI_SUCCESS.
-
-**/
-RETURN_STATUS
-EFIAPI
-BaseRngLibConstructor (
-  VOID
-  )
-{
-  UINT32  RegEcx;
-
-  //
-  // Determine RDRAND support by examining bit 30 of the ECX register returned by
-  // CPUID. A value of 1 indicates that processor support RDRAND instruction.
-  //
-  AsmCpuid (1, 0, 0, &RegEcx, 0);
-  ASSERT ((RegEcx & RDRAND_MASK) == RDRAND_MASK);
-
-  return RETURN_SUCCESS;
-}
 
 /**
   Generates a 16-bit random number.
@@ -72,11 +43,19 @@ GetRandomNumber16 (
 
   ASSERT (Rand != NULL);
 
+  if (Rand == NULL) {
+    return FALSE;
+  }
+
+  if (!ArchIsRngSupported ()) {
+    return FALSE;
+  }
+
   //
   // A loop to fetch a 16 bit random value with a retry count limit.
   //
-  for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {
+  for (Index = 0; Index < GETRANDOM_RETRY_LIMIT; Index++) {
-    if (AsmRdRand16 (Rand)) {
+    if (ArchGetRandomNumber16 (Rand)) {
       return TRUE;
     }
   }
@@ -105,11 +84,19 @@ GetRandomNumber32 (
 
   ASSERT (Rand != NULL);
 
+  if (Rand == NULL) {
+    return FALSE;
+  }
+
+  if (!ArchIsRngSupported ()) {
+    return FALSE;
+  }
+
   //
   // A loop to fetch a 32 bit random value with a retry count limit.
   //
-  for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {
+  for (Index = 0; Index < GETRANDOM_RETRY_LIMIT; Index++) {
-    if (AsmRdRand32 (Rand)) {
+    if (ArchGetRandomNumber32 (Rand)) {
       return TRUE;
     }
   }
@@ -138,11 +125,19 @@ GetRandomNumber64 (
 
   ASSERT (Rand != NULL);
 
+  if (Rand == NULL) {
+    return FALSE;
+  }
+
+  if (!ArchIsRngSupported ()) {
+    return FALSE;
+  }
+
   //
   // A loop to fetch a 64 bit random value with a retry count limit.
   //
-  for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {
+  for (Index = 0; Index < GETRANDOM_RETRY_LIMIT; Index++) {
-    if (AsmRdRand64 (Rand)) {
+    if (ArchGetRandomNumber64 (Rand)) {
       return TRUE;
     }
   }
@@ -169,6 +164,14 @@ GetRandomNumber128 (
 {
   ASSERT (Rand != NULL);
 
+  if (Rand == NULL) {
+    return FALSE;
+  }
+
+  if (!ArchIsRngSupported ()) {
+    return FALSE;
+  }
+
   //
   // Read first 64 bits
   //

MdePkg/Library/BaseRngLib/BaseRngLib.inf

@@ -1,9 +1,10 @@
 ## @file
 #  Instance of RNG (Random Number Generator) Library.
 #
-#  BaseRng Library that uses CPU RdRand instruction access to provide
+#  BaseRng Library that uses CPU RNG instructions (e.g. RdRand) to
-#  high-quality random numbers.
+#  provide random numbers.
 #
+#  Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
 #  Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -22,11 +23,25 @@
   CONSTRUCTOR                    = BaseRngLibConstructor
 
 #
-#  VALID_ARCHITECTURES           = IA32 X64
+#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
 #
 
-[Sources.Ia32, Sources.X64]
+[Sources]
   BaseRng.c
+  BaseRngLibInternals.h
+
+[Sources.Ia32, Sources.X64]
+  Rand/RdRand.c
+
+[Sources.AARCH64]
+  AArch64/Rndr.c
+  AArch64/ArmRng.h
+
+  AArch64/ArmReadIdIsar0.S   | GCC
+  AArch64/ArmRng.S           | GCC
+
+  AArch64/ArmReadIdIsar0.asm | MSFT
+  AArch64/ArmRng.asm         | MSFT
 
 [Packages]
   MdePkg/MdePkg.dec

MdePkg/Library/BaseRngLib/BaseRngLib.uni

@@ -1,8 +1,8 @@
 // /** @file
 // Instance of RNG (Random Number Generator) Library.
 //
-// BaseRng Library that uses CPU RdRand instruction access to provide
+// BaseRng Library that uses CPU RNG instructions to provide
-// high-quality random numbers.
+// random numbers.
 //
 // Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
 //
@@ -13,5 +13,4 @@
 
 #string STR_MODULE_ABSTRACT             #language en-US "Instance of RNG Library"
 
-#string STR_MODULE_DESCRIPTION          #language en-US "BaseRng Library that uses CPU RdRand instruction access to provide high-quality random numbers"
+#string STR_MODULE_DESCRIPTION          #language en-US "BaseRng Library that uses CPU RNG instructions to provide random numbers"
-

MdePkg/Library/BaseRngLib/BaseRngLibInternals.h

@@ -0,0 +1,78 @@
+/** @file
+
+  Architecture specific interface to RNG functionality.
+
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef BASE_RNGLIB_INTERNALS_H_
+
+/**
+  Generates a 16-bit random number.
+
+  @param[out] Rand     Buffer pointer to store the 16-bit random value.
+
+  @retval TRUE         Random number generated successfully.
+  @retval FALSE        Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+ArchGetRandomNumber16 (
+  OUT UINT16 *Rand
+  );
+
+/**
+  Generates a 32-bit random number.
+
+  @param[out] Rand     Buffer pointer to store the 32-bit random value.
+
+  @retval TRUE         Random number generated successfully.
+  @retval FALSE        Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+ArchGetRandomNumber32 (
+  OUT UINT32 *Rand
+  );
+
+/**
+  Generates a 64-bit random number.
+
+  @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
+ArchGetRandomNumber64 (
+  OUT UINT64 *Rand
+  );
+
+/**
+  Checks whether the RNG instruction is supported.
+
+  @retval TRUE         RNG instruction is supported.
+  @retval FALSE        RNG instruction is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+ArchIsRngSupported (
+  VOID
+  );
+
+#if defined (MDE_CPU_AARCH64)
+
+// RNDR, Random Number
+#define RNDR      S3_3_C2_C4_0
+
+#endif
+
+#endif    // BASE_RNGLIB_INTERNALS_H_

MdePkg/Library/BaseRngLib/Rand/RdRand.c

@@ -0,0 +1,131 @@
+/** @file
+  Random number generator services that uses RdRand instruction access
+  to provide high-quality random numbers.
+
+Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
+Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+
+#include "BaseRngLibInternals.h"
+
+//
+// Bit mask used to determine if RdRand instruction is supported.
+//
+#define RDRAND_MASK                  BIT30
+
+
+STATIC BOOLEAN mRdRandSupported;
+
+/**
+  The constructor function checks whether or not RDRAND instruction is supported
+  by the host hardware.
+
+  The constructor function checks whether or not RDRAND instruction is supported.
+  It will ASSERT() if RDRAND instruction is not supported.
+  It will always return EFI_SUCCESS.
+
+  @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+BaseRngLibConstructor (
+  VOID
+  )
+{
+  UINT32  RegEcx;
+
+  //
+  // Determine RDRAND support by examining bit 30 of the ECX register returned by
+  // CPUID. A value of 1 indicates that processor support RDRAND instruction.
+  //
+  AsmCpuid (1, 0, 0, &RegEcx, 0);
+  ASSERT ((RegEcx & RDRAND_MASK) == RDRAND_MASK);
+
+  mRdRandSupported = ((RegEcx & RDRAND_MASK) == RDRAND_MASK);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Generates a 16-bit random number.
+
+  @param[out] Rand     Buffer pointer to store the 16-bit random value.
+
+  @retval TRUE         Random number generated successfully.
+  @retval FALSE        Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+ArchGetRandomNumber16 (
+  OUT     UINT16                    *Rand
+  )
+{
+  return AsmRdRand16 (Rand);
+}
+
+/**
+  Generates a 32-bit random number.
+
+  @param[out] Rand     Buffer pointer to store the 32-bit random value.
+
+  @retval TRUE         Random number generated successfully.
+  @retval FALSE        Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+ArchGetRandomNumber32 (
+  OUT     UINT32                    *Rand
+  )
+{
+  return AsmRdRand32 (Rand);
+}
+
+/**
+  Generates a 64-bit random number.
+
+  @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
+ArchGetRandomNumber64 (
+  OUT     UINT64                    *Rand
+  )
+{
+  return AsmRdRand64 (Rand);
+}
+
+/**
+  Checks whether RDRAND is supported.
+
+  @retval TRUE         RDRAND is supported.
+  @retval FALSE        RDRAND is not supported.
+
+**/
+BOOLEAN
+EFIAPI
+ArchIsRngSupported (
+  VOID
+  )
+{
+  /*
+     Existing software depends on this always returning TRUE, so for
+     now hard-code it.
+
+     return mRdRandSupported;
+  */
+  return TRUE;
+}

MdePkg/MdePkg.dec

@@ -267,6 +267,11 @@
   #
   RegisterFilterLib|Include/Library/RegisterFilterLib.h
 
+[LibraryClasses.IA32, LibraryClasses.X64, LibraryClasses.AARCH64]
+  ##  @libraryclass  Provides services to generate random number.
+  #
+  RngLib|Include/Library/RngLib.h
+
 [LibraryClasses.IA32, LibraryClasses.X64]
   ##  @libraryclass  Abstracts both S/W SMI generation and detection.
   ##
@@ -288,10 +293,6 @@
   #
   SmmPeriodicSmiLib|Include/Library/SmmPeriodicSmiLib.h
 
-  ##  @libraryclass  Provides services to generate random number.
-  #
-  RngLib|Include/Library/RngLib.h
-
   ##  @libraryclass  Provides services to log the SMI handler registration.
   SmiHandlerProfileLib|Include/Library/SmiHandlerProfileLib.h
 

MdePkg/MdePkg.dsc

@@ -145,6 +145,9 @@
   MdePkg/Test/UnitTest/Library/BaseSafeIntLib/TestBaseSafeIntLibSmm.inf
   MdePkg/Test/UnitTest/Library/BaseSafeIntLib/TestBaseSafeIntLibUefiShell.inf
 
+[Components.IA32, Components.X64, Components.AARCH64]
+  MdePkg/Library/BaseRngLib/BaseRngLib.inf
+
 [Components.IA32, Components.X64]
   MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsic.inf
   MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsicSev.inf
@@ -168,7 +171,6 @@
   MdePkg/Library/BaseS3StallLib/BaseS3StallLib.inf
   MdePkg/Library/SmmMemLib/SmmMemLib.inf
   MdePkg/Library/SmmIoLib/SmmIoLib.inf
-  MdePkg/Library/BaseRngLib/BaseRngLib.inf
   MdePkg/Library/SmmPciExpressLib/SmmPciExpressLib.inf
   MdePkg/Library/SmiHandlerProfileLibNull/SmiHandlerProfileLibNull.inf
   MdePkg/Library/MmServicesTableLib/MmServicesTableLib.inf