ArmPlatform/ArmPlatformLib: Introduced ArmPlatformPeiBootAction()

This function allows platform to do any specific actions prior to
the start the PEI phase.
For instance, this function could be used by some platforms to initialize clocks that
are required at the early stage of the PEI phase.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
Acked-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@14347 6f19259b-4bc3-4df7-8a09-765794883524

ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm

@@ -22,6 +22,7 @@
   IMPORT  ArmPlatformGetCorePosition
   IMPORT  ArmPlatformIsPrimaryCore
   IMPORT  ArmReadMpidr
+  IMPORT  ArmPlatformPeiBootAction
   EXPORT  _ModuleEntryPoint
   
   PRESERVE8
@@ -30,6 +31,9 @@
 StartupAddr        DCD      CEntryPoint
 
 _ModuleEntryPoint
+  // Do early platform specific actions
+  bl    ArmPlatformPeiBootAction
+
   // Identify CPU ID
   bl    ArmReadMpidr
   // Keep a copy of the MpId register value