[PATCH edk2-platforms v2 14/18] ARM/VExpressPkg: Reserving framebuffer at build

[evan.lloyd@arm.com]

From: Girish Pathak <girish.pathak at arm.com>

This change uses two PCDs, PcdArmLcdFrameBufferBase and
PcdArmLcdFrameBufferSize introduced in correspondiong EDK2 patch to
reserve framebuffer in DRAM if these values are defined in platform
specific DSC file, avoiding the need to allocate dynamically.
This allows the framebuffer to appear as "I/O memory" outside of the
normal RAM map, which is similar to the "VRAM" case.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Girish Pathak <girish.pathak@arm.com>
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
---
 Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/ArmVExpressLib.inf |  4 +++-
 Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/RTSMMem.c          | 20 ++++++++++++++++++--
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/ArmVExpressLib.inf b/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/ArmVExpressLib.inf
index 4cbd2ff4b4faf11ccd4fe30117708d7cc4c1bf0e..c70c4ce64826174e6d15611de640ad3b902835b9 100644
--- a/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/ArmVExpressLib.inf
+++ b/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/ArmVExpressLib.inf
@@ -1,5 +1,5 @@
 #/* @file
-#  Copyright (c) 2011-2014, ARM Limited. All rights reserved.
+#  Copyright (c) 2011-2017, 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
@@ -57,6 +57,8 @@ [FixedPcd]
   gArmTokenSpaceGuid.PcdArmPrimaryCore
 
   gArmPlatformTokenSpaceGuid.PcdCoreCount
+  gArmPlatformTokenSpaceGuid.PcdArmLcdDdrFrameBufferBase
+  gArmPlatformTokenSpaceGuid.PcdArmLcdDdrFrameBufferSize
 
 [Ppis]
   gArmMpCoreInfoPpiGuid
diff --git a/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/RTSMMem.c b/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/RTSMMem.c
index 6379e81751fca5e7972c5c30f305be65fd1ae71d..1e8f3205312ebf30fa1666130bc944261384359a 100644
--- a/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/RTSMMem.c
+++ b/Platform/ARM/VExpressPkg/Library/ArmVExpressLibRTSM/RTSMMem.c
@@ -1,6 +1,6 @@
 /** @file
 *
-*  Copyright (c) 2011-2016, ARM Limited. All rights reserved.
+*  Copyright (c) 2011-2017, 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
@@ -20,8 +20,10 @@
 #include <Library/MemoryAllocationLib.h>
 #include <ArmPlatform.h>
 
+#define FRAME_BUFFER_DESCRIPTOR ((FixedPcdGet64 (PcdArmLcdDdrFrameBufferBase) != 0) ? 1 : 0)
+
 // Number of Virtual Memory Map Descriptors
-#define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS          9
+#define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS (9 + FRAME_BUFFER_DESCRIPTOR)
 
 // DDR attributes
 #define DDR_ATTRIBUTES_CACHED   ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK
@@ -142,6 +144,20 @@ ArmPlatformGetVirtualMemoryMap (
   //
   VirtualMemoryTable[Index].Attributes = ARM_MEMORY_REGION_ATTRIBUTE_UNCACHED_UNBUFFERED;
 
+  // Map region for the frame buffer in the system RAM
+#if (FixedPcdGet32 (PcdArmLcdDdrFrameBufferSize) != 0)
+  VirtualMemoryTable[++Index].PhysicalBase = FixedPcdGet64 (PcdArmLcdDdrFrameBufferBase);
+  VirtualMemoryTable[Index].VirtualBase = FixedPcdGet64 (PcdArmLcdDdrFrameBufferBase);
+  VirtualMemoryTable[Index].Length = FixedPcdGet32 (PcdArmLcdDdrFrameBufferSize);
+  // Map as Normal Non-Cacheable memory, so that we can use the accelerated
+  // SetMem/CopyMem routines that may use unaligned accesses or
+  // DC ZVA instructions. If mapped as device memory, these routine may cause
+  // alignment faults.
+  // NOTE: The attribute value is misleading, it indicates memory map type as
+  // an un-cached, un-buffered but allows buffering and reordering.
+  VirtualMemoryTable[Index].Attributes = ARM_MEMORY_REGION_ATTRIBUTE_UNCACHED_UNBUFFERED;
+#endif
+
   // Map sparse memory region if present
   if (HasSparseMemory) {
     VirtualMemoryTable[++Index].PhysicalBase = SparseMemoryBase;
-- 
Guid("CE165669-3EF3-493F-B85D-6190EE5B9759")