MdePkg: Add Random Number Generator (RNG) PPI

(cherry picked from commit de5c119)

REF:tianocore#10529

Adds a new PPI that serves the same purpose as EFI_RNG_PROTOCOL in
DXE. This PPI can be produced by a PEIM to provide a dynamic interface
to RNG services in PEI.

Signed-off-by: Michael Kubacki <[email protected]>
(cherry picked from commit de5c119)

Change-Id: I5da2fd339552908f044ebf5b5d2c8b2fd90a665b

MdePkg/Include/Ppi/Rng.h

@@ -0,0 +1,27 @@
+/** @file
+  The Random Number Generator (RNG) PPI is used to provide random bits for use
+  in PEIMs, or entropy for seeding other random number generators. The PPI was
+  introduced in the PI 1.9 Specification.
+
+  Copyright (c) Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef RNG_PPI_H_
+#define RNG_PPI_H_
+
+#include <Guid/Rng.h>
+
+///
+/// Global ID for the Random Number Generator PPI
+///
+#define RNG_PPI_GUID \
+  { \
+    0xeaed0a7e, 0x1a70, 0x4c2b, { 0x85, 0x58, 0x37, 0x17, 0x74, 0x56, 0xd8, 0x06 } \
+  }
+
+typedef EFI_RNG_INTERFACE RNG_PPI;
+
+extern EFI_GUID  gEfiRngPpiGuid;
+
+#endif

MdePkg/MdePkg.dec

@@ -1086,6 +1086,9 @@
   ## Include/Ppi/DelayedDispatch.h
   gEfiPeiDelayedDispatchPpiGuid  = { 0x869c711d, 0x649c, 0x44fe, { 0x8b, 0x9e, 0x2c, 0xbb, 0x29, 0x11, 0xc3, 0xe6 }}
 
+  ## Include/Ppi/Rng.h
+  gEfiRngPpiGuid                 = { 0xeaed0a7e, 0x1a70, 0x4c2b, { 0x85, 0x58, 0x37, 0x17, 0x74, 0x56, 0xd8, 0x06 }}
+
 [Protocols]
   ## Include/Protocol/MemoryAccept.h
   gEdkiiMemoryAcceptProtocolGuid = { 0x38c74800, 0x5590, 0x4db4, { 0xa0, 0xf3, 0x67, 0x5d, 0x9b, 0x8e, 0x80, 0x26 }}