ArmPkg/ArmPkg.dec: Redefined PcdSystemMemory(Base|Size) as UINT64

The System Memory region might be out of the 32-bit memory space.

This change has been validated on the FVP AArch64 model using 4GB
of DRAM at 0x8_0000_0000:

-  # System Memory (2GB)
-  gArmTokenSpaceGuid.PcdSystemMemoryBase|0x80000000
-  gArmTokenSpaceGuid.PcdSystemMemorySize|0x80000000
+  # System Memory (4GB)
+  gArmTokenSpaceGuid.PcdSystemMemoryBase|0x800000000
+  gArmTokenSpaceGuid.PcdSystemMemorySize|0x100000000

EFI Shell and Linux kernel boot successfully.

Note: This change has not been validated on AArch32. I expect some
early assembly code to not work.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>




git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15093 6f19259b-4bc3-4df7-8a09-765794883524

ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S

@@ -50,8 +50,8 @@ _SetSVCMode:
 // at the top of the DRAM)
 _SetupStackPosition:
   // Compute Top of System Memory
-  LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryBase), r1)
-  LoadConstantToReg (FixedPcdGet32(PcdSystemMemorySize), r2)
+  LoadConstantToReg (FixedPcdGet64 (PcdSystemMemoryBase), r1)
+  LoadConstantToReg (FixedPcdGet64 (PcdSystemMemorySize), r2)
   sub   r2, r2, #1
   add   r1, r1, r2      // r1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize