SecurityPkg/RngDxe: Add Arm support of RngDxe

Bugzilla: 3668 (https://bugzilla.tianocore.org/show_bug.cgi?id=3668)

Add RngDxe support for Arm. This implementation uses the ArmTrngLib
to support the RawAlgorithm and doens't support the RNDR instruction.

To re-use the RngGetRNG(), RngGetInfo() and FreeAvailableAlgorithms()
functions, create Arm/AArch64 files which implement the arch specific
function GetAvailableAlgorithms(). Indeed, FEAT_RNG instruction is not
supported on Arm.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Acked-by: Jiewen Yao <jiewen.yao@intel.com>

SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/AArch64Algo.c

@@ -0,0 +1,72 @@
+/** @file
+  Aarch64 specific code.
+
+  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/ArmTrngLib.h>
+
+#include "RngDxeInternals.h"
+
+// Maximum number of Rng algorithms.
+#define RNG_AVAILABLE_ALGO_MAX  2
+
+/** Allocate and initialize mAvailableAlgoArray with the available
+    Rng algorithms. Also update mAvailableAlgoArrayCount.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_OUT_OF_RESOURCES    Could not allocate memory.
+**/
+EFI_STATUS
+EFIAPI
+GetAvailableAlgorithms (
+  VOID
+  )
+{
+  UINT64  DummyRand;
+  UINT16  MajorRevision;
+  UINT16  MinorRevision;
+
+  // Rng algorithms 2 times, one for the allocation, one to populate.
+  mAvailableAlgoArray = AllocateZeroPool (RNG_AVAILABLE_ALGO_MAX);
+  if (mAvailableAlgoArray == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // Check RngGetBytes() before advertising PcdCpuRngSupportedAlgorithm.
+  if (!EFI_ERROR (RngGetBytes (sizeof (DummyRand), (UINT8 *)&DummyRand))) {
+    CopyMem (
+      &mAvailableAlgoArray[mAvailableAlgoArrayCount],
+      PcdGetPtr (PcdCpuRngSupportedAlgorithm),
+      sizeof (EFI_RNG_ALGORITHM)
+      );
+    mAvailableAlgoArrayCount++;
+
+    DEBUG_CODE_BEGIN ();
+    if (IsZeroGuid (PcdGetPtr (PcdCpuRngSupportedAlgorithm))) {
+      DEBUG ((
+        DEBUG_WARN,
+        "PcdCpuRngSupportedAlgorithm should be a non-zero GUID\n"
+        ));
+    }
+
+    DEBUG_CODE_END ();
+  }
+
+  // Raw algorithm (Trng)
+  if (!EFI_ERROR (GetArmTrngVersion (&MajorRevision, &MinorRevision))) {
+    CopyMem (
+      &mAvailableAlgoArray[mAvailableAlgoArrayCount],
+      &gEfiRngAlgorithmRaw,
+      sizeof (EFI_RNG_ALGORITHM)
+      );
+    mAvailableAlgoArrayCount++;
+  }
+
+  return EFI_SUCCESS;
+}

SecurityPkg/RandomNumberGenerator/RngDxe/Arm/ArmAlgo.c

@@ -0,0 +1,51 @@
+/** @file
+  Arm specific code.
+
+  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/ArmTrngLib.h>
+
+#include "RngDxeInternals.h"
+
+// Maximum number of Rng algorithms.
+#define RNG_AVAILABLE_ALGO_MAX  1
+
+/** Allocate and initialize mAvailableAlgoArray with the available
+    Rng algorithms. Also update mAvailableAlgoArrayCount.
+
+  @retval EFI_SUCCESS             The function completed successfully.
+  @retval EFI_OUT_OF_RESOURCES    Could not allocate memory.
+**/
+EFI_STATUS
+EFIAPI
+GetAvailableAlgorithms (
+  VOID
+  )
+{
+  UINT16  MajorRevision;
+  UINT16  MinorRevision;
+
+  // Rng algorithms 2 times, one for the allocation, one to populate.
+  mAvailableAlgoArray = AllocateZeroPool (RNG_AVAILABLE_ALGO_MAX);
+  if (mAvailableAlgoArray == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // Raw algorithm (Trng)
+  if (!EFI_ERROR (GetArmTrngVersion (&MajorRevision, &MinorRevision))) {
+    CopyMem (
+      &mAvailableAlgoArray[mAvailableAlgoArrayCount],
+      &gEfiRngAlgorithmRaw,
+      sizeof (EFI_RNG_ALGORITHM)
+      );
+    mAvailableAlgoArrayCount++;
+  }
+
+  return EFI_SUCCESS;
+}

SecurityPkg/RandomNumberGenerator/RngDxe/ArmRngDxe.c

@@ -28,70 +28,10 @@
 #include <Library/MemoryAllocationLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/RngLib.h>
-#include <Library/DebugLib.h>
-#include <Library/ArmTrngLib.h>
 #include <Protocol/Rng.h>
 
 #include "RngDxeInternals.h"
 
-// Maximum number of Rng algorithms.
-#define RNG_AVAILABLE_ALGO_MAX  2
-
-/** Allocate and initialize mAvailableAlgoArray with the available
-    Rng algorithms. Also update mAvailableAlgoArrayCount.
-
-  @retval EFI_SUCCESS             The function completed successfully.
-  @retval EFI_OUT_OF_RESOURCES    Could not allocate memory.
-**/
-EFI_STATUS
-EFIAPI
-GetAvailableAlgorithms (
-  VOID
-  )
-{
-  UINT64  DummyRand;
-  UINT16  MajorRevision;
-  UINT16  MinorRevision;
-
-  // Rng algorithms 2 times, one for the allocation, one to populate.
-  mAvailableAlgoArray = AllocateZeroPool (RNG_AVAILABLE_ALGO_MAX);
-  if (mAvailableAlgoArray == NULL) {
-    return EFI_OUT_OF_RESOURCES;
-  }
-
-  // Check RngGetBytes() before advertising PcdCpuRngSupportedAlgorithm.
-  if (!EFI_ERROR (RngGetBytes (sizeof (DummyRand), (UINT8 *)&DummyRand))) {
-    CopyMem (
-      &mAvailableAlgoArray[mAvailableAlgoArrayCount],
-      PcdGetPtr (PcdCpuRngSupportedAlgorithm),
-      sizeof (EFI_RNG_ALGORITHM)
-      );
-    mAvailableAlgoArrayCount++;
-
-    DEBUG_CODE_BEGIN ();
-    if (IsZeroGuid (PcdGetPtr (PcdCpuRngSupportedAlgorithm))) {
-      DEBUG ((
-        DEBUG_WARN,
-        "PcdCpuRngSupportedAlgorithm should be a non-zero GUID\n"
-        ));
-    }
-
-    DEBUG_CODE_END ();
-  }
-
-  // Raw algorithm (Trng)
-  if (!EFI_ERROR (GetArmTrngVersion (&MajorRevision, &MinorRevision))) {
-    CopyMem (
-      &mAvailableAlgoArray[mAvailableAlgoArrayCount],
-      &gEfiRngAlgorithmRaw,
-      sizeof (EFI_RNG_ALGORITHM)
-      );
-    mAvailableAlgoArrayCount++;
-  }
-
-  return EFI_SUCCESS;
-}
-
 /** Free mAvailableAlgoArray.
 **/
 VOID

SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf

@@ -28,7 +28,7 @@
 #
 # The following information is for reference only and not required by the build tools.
 #
-#  VALID_ARCHITECTURES           = IA32 X64 AARCH64
+#  VALID_ARCHITECTURES           = IA32 X64 AARCH64 ARM
 #
 
 [Sources.common]
@@ -41,10 +41,16 @@
   Rand/AesCore.c
   Rand/AesCore.h
 
-[Sources.AARCH64]
+[Sources.AARCH64, Sources.ARM]
   ArmRngDxe.c
   ArmTrng.c
 
+[Sources.AARCH64]
+  AArch64/AArch64Algo.c
+
+[Sources.ARM]
+  Arm/ArmAlgo.c
+
 [Packages]
   MdeModulePkg/MdeModulePkg.dec
   MdePkg/MdePkg.dec
@@ -59,7 +65,7 @@
   TimerLib
   RngLib
 
-[LibraryClasses.AARCH64]
+[LibraryClasses.AARCH64, LibraryClasses.ARM]
   ArmTrngLib
 
 [Guids]

SecurityPkg/SecurityPkg.dsc

@@ -291,7 +291,7 @@
   SecurityPkg/EnrollFromDefaultKeysApp/EnrollFromDefaultKeysApp.inf
   SecurityPkg/VariableAuthenticated/SecureBootDefaultKeysDxe/SecureBootDefaultKeysDxe.inf
 
-[Components.IA32, Components.X64, Components.AARCH64]
+[Components.IA32, Components.X64, Components.AARCH64, Components.ARM]
   #
   # Random Number Generator
   #