[PATCH v3 18/21] SecurityPkg/RngDxe: Add debug warning for NULL PcdCpuRngSupportedAlgorithm

["PierreGondois" <pierre.gondois@arm.com>]

From: Pierre Gondois <pierre.gondois@arm.com>

PcdCpuRngSupportedAlgorithm should allow to identify the the algorithm
used by the RNDR CPU instruction to generate a random number.
Add a debug warning if the Pcd is not set.

Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
---
 .../RandomNumberGenerator/RngDxe/AArch64/RngDxe.c      | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c b/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c
index ee3f1ee78434..ffa32a29dc6a 100644
--- a/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c
+++ b/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c
@@ -63,6 +63,16 @@ RngInitAvailableAlgoArray (
       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)
-- 
2.25.1