From b6efc505e4d6eb2055a39afd0a1ee67846a1e5f9 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@kernel.org>
Date: Sun, 25 Sep 2022 17:22:04 +0200
Subject: [PATCH] ArmVirtPkg/ArmVirtQemu: omit PCD PEIM unless TPM support is
 enabled

The TPM discovery code relies on a dynamic PCD to communicate the TPM
base address to other components. But no other code relies on dynamic
PCDs in the PEI phase so let's drop the PCD PEIM when TPM support is not
enabled.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 ArmVirtPkg/ArmVirtQemu.dsc | 22 +++++++++++++++++-----
 ArmVirtPkg/ArmVirtQemu.fdf |  2 +-
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/ArmVirtPkg/ArmVirtQemu.dsc b/ArmVirtPkg/ArmVirtQemu.dsc
index e3686c7ee3..fbd9270db5 100644
--- a/ArmVirtPkg/ArmVirtQemu.dsc
+++ b/ArmVirtPkg/ArmVirtQemu.dsc
@@ -288,10 +288,15 @@
   #
   # TPM2 support
   #
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress|0x0
 !if $(TPM2_ENABLE) == TRUE
+  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress|0x0
   gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid|{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
   gEfiSecurityPkgTokenSpaceGuid.PcdTpm2HashMask|0
+!else
+[PcdsPatchableInModule]
+  # make this PCD patchable instead of dynamic when TPM support is not enabled
+  # this permits setting the PCD in unreachable code without pulling in dynamic PCD support
+  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress|0x0
 !endif
 
 [PcdsDynamicHii]
@@ -304,6 +309,13 @@
 
   gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|L"Timeout"|gEfiGlobalVariableGuid|0x0|5
 
+[LibraryClasses.common.PEI_CORE, LibraryClasses.common.PEIM]
+!if $(TPM2_ENABLE) == TRUE
+  PcdLib|MdePkg/Library/PeiPcdLib/PeiPcdLib.inf
+!else
+  PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
+!endif
+
 ################################################################################
 #
 # Components Section - list of all EDK II Modules needed by this Platform
@@ -315,10 +327,6 @@
   #
   ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
   MdeModulePkg/Core/Pei/PeiMain.inf
-  MdeModulePkg/Universal/PCD/Pei/Pcd.inf {
-    <LibraryClasses>
-      PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
-  }
   ArmPlatformPkg/PlatformPei/PlatformPeim.inf
   ArmVirtPkg/MemoryInitPei/MemoryInitPeim.inf {
     <LibraryClasses>
@@ -329,6 +337,10 @@
   ArmPkg/Drivers/CpuPei/CpuPei.inf
 
 !if $(TPM2_ENABLE) == TRUE
+  MdeModulePkg/Universal/PCD/Pei/Pcd.inf {
+    <LibraryClasses>
+      PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
+  }
   MdeModulePkg/Universal/ResetSystemPei/ResetSystemPei.inf {
     <LibraryClasses>
       ResetSystemLib|ArmVirtPkg/Library/ArmVirtPsciResetSystemPeiLib/ArmVirtPsciResetSystemPeiLib.inf
diff --git a/ArmVirtPkg/ArmVirtQemu.fdf b/ArmVirtPkg/ArmVirtQemu.fdf
index c85e36b185..764f652afd 100644
--- a/ArmVirtPkg/ArmVirtQemu.fdf
+++ b/ArmVirtPkg/ArmVirtQemu.fdf
@@ -109,10 +109,10 @@ READ_LOCK_STATUS   = TRUE
   INF ArmPlatformPkg/PlatformPei/PlatformPeim.inf
   INF ArmVirtPkg/MemoryInitPei/MemoryInitPeim.inf
   INF ArmPkg/Drivers/CpuPei/CpuPei.inf
-  INF MdeModulePkg/Universal/PCD/Pei/Pcd.inf
   INF MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf
 
 !if $(TPM2_ENABLE) == TRUE
+  INF MdeModulePkg/Universal/PCD/Pei/Pcd.inf
   INF MdeModulePkg/Universal/ResetSystemPei/ResetSystemPei.inf
   INF OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
   INF SecurityPkg/Tcg/Tcg2Pei/Tcg2Pei.inf