ArmPsciResetSystemLib: read PSCI method in constructor

As this library is used in the implementation of a Runtime Service,
make sure to access dynamic PCDs only in the constructor.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16108 6f19259b-4bc3-4df7-8a09-765794883524

ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.c

@@ -25,6 +25,18 @@
 
 #include <IndustryStandard/ArmStdSmc.h>
 
+STATIC UINT32 mArmPsciMethod;
+
+RETURN_STATUS
+EFIAPI
+ArmPsciResetSystemLibConstructor (
+  VOID
+  )
+{
+  mArmPsciMethod = PcdGet32 (PcdArmPsciMethod);
+  return RETURN_SUCCESS;
+}
+
 /**
   Resets the entire platform.
 
@@ -69,7 +81,7 @@ LibResetSystem (
     return EFI_UNSUPPORTED;
   }
 
-  switch (PcdGet32 (PcdArmPsciMethod)) {
+  switch (mArmPsciMethod) {
   case 1:
     ArmCallHvc (&ArmHvcArgs);
     break;

ArmPkg/Library/ArmPsciResetSystemLib/ArmPsciResetSystemLib.inf

@@ -21,6 +21,7 @@
   MODULE_TYPE                    = BASE
   VERSION_STRING                 = 1.0
   LIBRARY_CLASS                  = EfiResetSystemLib
+  CONSTRUCTOR                    = ArmPsciResetSystemLibConstructor
 
 [Sources]
   ArmPsciResetSystemLib.c