ArmPlatformPkg: Introduce ArmPlatformGlobalVariableLib

This library hides where the 'XIP' Global Variable are located in the memory.
It is expected the Sec/PrePi modules define the Global Variable area through
the GlobalVariable HOB.

The ArmPlatformGlobalVariableLib library allows access to global variables by
their offsets in this region.




git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12420 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 76 insertions, 0 deletions

diff --git a/ArmPlatformPkg/Library/ArmPlatformGlobalVariableLib/PrePi/PrePiArmPlatformGlobalVariableLib.c b/ArmPlatformPkg/Library/ArmPlatformGlobalVariableLib/PrePi/PrePiArmPlatformGlobalVariableLib.c
new file mode 100644
index 0000000000..3d050bd150
--- /dev/null
+++ b/ArmPlatformPkg/Library/ArmPlatformGlobalVariableLib/PrePi/PrePiArmPlatformGlobalVariableLib.c
@@ -0,0 +1,76 @@
+/** @file
+*
+*  Copyright (c) 2011, ARM Limited. All rights reserved.
+*
+*  This program and the accompanying materials
+*  are licensed and made available under the terms and conditions of the BSD License
+*  which accompanies this distribution.  The full text of the license may be found at
+*  http://opensource.org/licenses/bsd-license.php
+*
+*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+*
+**/
+
+#include <Uefi.h>
+#include <Library/ArmPlatformGlobalVariableLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/PcdLib.h>
+
+#define IS_XIP() ((PcdGet32 (PcdFdBaseAddress) > (PcdGet32 (PcdSystemMemoryBase) + PcdGet32 (PcdSystemMemorySize))) || \
+                  ((PcdGet32 (PcdFdBaseAddress) + PcdGet32 (PcdFdSize)) < PcdGet32 (PcdSystemMemoryBase)))
+
+// Declared by ArmPlatformPkg/PrePi Module
+extern UINTN mGlobalVariableBase;
+
+VOID
+ArmPlatformGetGlobalVariable (
+  IN  UINTN     VariableOffset,
+  IN  UINTN     VariableSize,
+  OUT VOID*     Variable
+  )
+{
+  UINTN  GlobalVariableBase;
+
+  if (IS_XIP()) {
+    // In Case of XIP, we expect the Primary Stack at the top of the System Memory
+    GlobalVariableBase = PcdGet32 (PcdSystemMemoryBase) + PcdGet32 (PcdSystemMemorySize) - PcdGet32 (PcdPeiGlobalVariableSize);
+  } else {
+    GlobalVariableBase = mGlobalVariableBase;
+  }
+
+  if (VariableSize == 4) {
+    *(UINT32*)Variable = ReadUnaligned32 ((CONST UINT32*)(GlobalVariableBase + VariableOffset));
+  } else if (VariableSize == 8) {
+    *(UINT32*)Variable = ReadUnaligned64 ((CONST UINT64*)(GlobalVariableBase + VariableOffset));
+  } else {
+    CopyMem (Variable, (VOID*)(GlobalVariableBase + VariableOffset), VariableSize);
+  }
+}
+
+VOID
+ArmPlatformSetGlobalVariable (
+  IN  UINTN     VariableOffset,
+  IN  UINTN     VariableSize,
+  OUT VOID*     Variable
+  )
+{
+  UINTN  GlobalVariableBase;
+
+  if (IS_XIP()) {
+    // In Case of XIP, we expect the Primary Stack at the top of the System Memory
+    GlobalVariableBase = PcdGet32 (PcdSystemMemoryBase) + PcdGet32 (PcdSystemMemorySize) - PcdGet32 (PcdPeiGlobalVariableSize);
+  } else {
+    GlobalVariableBase = mGlobalVariableBase;
+  }
+
+  if (VariableSize == 4) {
+    WriteUnaligned32 ((UINT32*)(GlobalVariableBase + VariableOffset), *(UINT32*)Variable);
+  } else if (VariableSize == 8) {
+    WriteUnaligned64 ((UINT64*)(GlobalVariableBase + VariableOffset), *(UINT64*)Variable);
+  } else {
+    CopyMem ((VOID*)(GlobalVariableBase + VariableOffset), Variable, VariableSize);
+  }
+}
+