From 2b1bfcd5076ec877b558c3d6ae25079d6ef83564 Mon Sep 17 00:00:00 2001
From: kenlautner <85201046+kenlautner@users.noreply.github.com>
Date: Fri, 7 Jul 2023 10:55:25 -0700
Subject: [PATCH] Added logic to delete the Memory Type Information variable on
 a capsule update. (#271)

## Description

Added logic to delete the Memory Type Information variable on a capsule
update. This is because in rare circumstance where a new memory type is
added (or a memory type is removed) a capsule update will cause a
mismatch of memory types. Removing the variable and thus forcing a clean
memory bucket discovery solves this issue.

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- [ ] Impacts functionality?
- **Functionality** - Does the change ultimately impact how firmware
functions?
- Examples: Add a new library, publish a new PPI, update an algorithm,
...
- [ ] Impacts security?
- **Security** - Does the change have a direct security impact on an
application,
    flow, or firmware?
  - Examples: Crypto algorithm change, buffer overflow fix, parameter
    validation improvement, ...
- [ ] Breaking change?
- **Breaking change** - Will anyone consuming this change experience a
break
    in build or boot behavior?
- Examples: Add a new library class, move a module to a different repo,
call
    a function in a new library class in a pre-existing module, ...
- [ ] Includes tests?
  - **Tests** - Does the change include any explicit test code?
  - Examples: Unit tests, integration tests, robot tests, ...
- [ ] Includes documentation?
- **Documentation** - Does the change contain explicit documentation
additions
    outside direct code modifications (and comments)?
- Examples: Update readme file, add feature readme file, link to
documentation
    on an a separate Web page, ...

## How This Was Tested

Tested on a platform where there is a capsule update between two
versions of firmware with a different amount of memory types. Without
this change the transition from temp ram to permanent memory breaks but
with this change the device correctly goes to the default memory bucket
configuration and is able to boot.

## Integration Instructions

N/A
---
 .../PlatformBootManagerLib/BdsPlatform.c      | 21 +++++++++++++++++++
 .../PlatformBootManagerLib/BdsPlatform.h      |  1 +
 2 files changed, 22 insertions(+)

diff --git a/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.c b/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.c
index 9b41249d7f..e4735d5d26 100644
--- a/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.c
+++ b/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.c
@@ -349,6 +349,8 @@ PlatformBootManagerAfterConsole (
   )
 {
   EFI_STATUS  Status;
+  UINT32      Attributes;
+  UINTN       VariableSize = 0;
 
   //  EFI_INPUT_KEY                 Key;
 
@@ -388,6 +390,25 @@ PlatformBootManagerAfterConsole (
     case BOOT_ON_FLASH_UPDATE:
       EfiBootManagerConnectAll ();
       DEBUG ((DEBUG_INFO, "[%a] - signalling capsules are ready for processing\n", __FUNCTION__));
+      DEBUG ((DEBUG_INFO, "[%a] - Deleting Memory Type Information variable for capsule update\n", __FUNCTION__));
+      Status = gRT->GetVariable (
+                      EFI_MEMORY_TYPE_INFORMATION_VARIABLE_NAME,
+                      &gEfiMemoryTypeInformationGuid,
+                      &Attributes,
+                      &VariableSize,
+                      NULL
+                      );
+      if (Status == EFI_BUFFER_TOO_SMALL) {
+        Status = gRT->SetVariable (
+                        EFI_MEMORY_TYPE_INFORMATION_VARIABLE_NAME,
+                        &gEfiMemoryTypeInformationGuid,
+                        Attributes,
+                        0,
+                        NULL
+                        );
+        ASSERT_EFI_ERROR (Status);
+      }
+
       EfiEventGroupSignal (&gMuReadyToProcessCapsulesNotifyGuid);
       Status = ProcessCapsules ();
 
diff --git a/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.h b/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.h
index 621e22b98f..b9f2442f0a 100644
--- a/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.h
+++ b/MsCorePkg/Library/PlatformBootManagerLib/BdsPlatform.h
@@ -22,6 +22,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 #include <Guid/CapsuleVendor.h>
 
+#include <Guid/MemoryTypeInformation.h>
 #include <Guid/EventGroup.h>
 #include <Guid/GlobalVariable.h>
 #include <Guid/MemoryOverwriteControl.h>