[PATCH v6 2/7] MdeModulePkg: Introduce ExitBootServicesCallbackProtocol

["Dionna Glaze" <dionnaglaze@google.com>]

This introduces a callback after the time that the timer is disabled and before
the MemoryMap is finalized.

This callback is useful to make final changes to the memory map due to protocols
initiated (or not initiated) by the OS loader.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: "Min M. Xu" <min.m.xu@intel.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Andrew Fish <afish@apple.com>
Cc: "Michael D. Kinney" <michael.d.kinney@intel.com>

Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
---
 MdeModulePkg/Include/Protocol/ExitBootServicesCallback.h | 40 ++++++++++++++++++++
 MdeModulePkg/MdeModulePkg.dec                            |  3 ++
 2 files changed, 43 insertions(+)

diff --git a/MdeModulePkg/Include/Protocol/ExitBootServicesCallback.h b/MdeModulePkg/Include/Protocol/ExitBootServicesCallback.h
new file mode 100644
index 0000000000..5c9f973b79
--- /dev/null
+++ b/MdeModulePkg/Include/Protocol/ExitBootServicesCallback.h
@@ -0,0 +1,40 @@
+/** @file
+  The file provides the protocol that allows callbacks in ExitBootServices
+  immediately before TerminateMemoryMap.
+
+  Copyright (c) 2022, Google LLC. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+#ifndef EXIT_BOOT_SERVICES_CALLBACK_H_
+#define EXIT_BOOT_SERVICES_CALLBACK_H_
+
+/* This protocol is internal to EDK2 only */
+
+#define EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL_GUID   {0xf5684799,                                             0x9a33,                                                 0x40f7,                                                 {0xa1, 0x5c, 0x10, 0x8e, 0x0e, 0x6b, 0x45, 0x25}}
+
+typedef struct _EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL
+    EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL;
+
+/**
+  @param This A pointer to a EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL.
+
+  The returned status may only be EFI_SUCCESS or EFI_INVALID_PARAMETER.
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_TERMINATE_MEMORY_MAP_PREHOOK)(
+  IN  EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL  *This
+  );
+
+///
+/// The EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL allows callbacks in
+/// ExitBootServices immediately before TerminateMemoryMap.
+///
+struct _EDKII_EXIT_BOOT_SERVICES_CALLBACK_PROTOCOL {
+  EDKII_TERMINATE_MEMORY_MAP_PREHOOK  TerminateMemoryMapPrehook;
+  BOOLEAN                             Disabled;
+};
+
+extern EFI_GUID  gEdkiiExitBootServicesCallbackProtocolGuid;
+
+#endif
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 58e6ab0048..add4e304ca 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -677,6 +677,9 @@
   ## Include/Protocol/VariablePolicy.h
   gEdkiiVariablePolicyProtocolGuid = { 0x81D1675C, 0x86F6, 0x48DF, { 0xBD, 0x95, 0x9A, 0x6E, 0x4F, 0x09, 0x25, 0xC3 } }
 
+  ## Include/Protocol/ExitBootServicesCallback.h
+  gEdkiiExitBootServicesCallbackProtocolGuid = { 0xf5684799, 0x9a33, 0x40f7, {0xa1, 0x5c, 0x10, 0x8e, 0x0e, 0x6b, 0x45, 0x25 }}
+
 [PcdsFeatureFlag]
   ## Indicates if the platform can support update capsule across a system reset.<BR><BR>
   #   TRUE  - Supports update capsule across a system reset.<BR>
-- 
2.38.0.rc1.362.ged0d419d3c-goog