[PATCH v3 13/16] ArmPlatformPkg: Reserving framebuffer at build

[Girish Pathak <girish.pathak@arm.com>]

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

Currently framebuffer memory is either reserved in special VRAM or
dynamically allocated using boot services memory allocation functions.
When allocated using boot services calls the memory has to be allocated
as EfiBootServicesData. Unfortunately failures have been seen with this
case.  There is also an unfortunate lack of control on the placement of
the framebuffer.

This change introduces two PCDs, PcdArmLcdFrameBufferBase and
PcdArmLcdFrameBufferSize which enable build time reservation of the
framebuffer, 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.

This change has no impact on current code, only enables the option
of build time reservation of framebuffers.

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>
---
 ArmPlatformPkg/ArmPlatformPkg.dec | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ArmPlatformPkg/ArmPlatformPkg.dec b/ArmPlatformPkg/ArmPlatformPkg.dec
index 5231ea822f05c2f281a6190d6eae0fc7d0bc0cb3..5c702718a78a78e6c67ab407e198382e0a0df4be 100644
--- a/ArmPlatformPkg/ArmPlatformPkg.dec
+++ b/ArmPlatformPkg/ArmPlatformPkg.dec
@@ -93,6 +93,11 @@ [PcdsFixedAtBuild.common]
   gArmPlatformTokenSpaceGuid.PcdPL111LcdBase|0x0|UINT32|0x00000026
   gArmPlatformTokenSpaceGuid.PcdArmHdLcdBase|0x0|UINT32|0x00000027
 
+  ## Default size for display modes upto 1920x1080 (1920 * 1080 * 4 Bytes Per Pixel)
+  gArmPlatformTokenSpaceGuid.PcdArmLcdDdrFrameBufferSize|0x7E9000|UINT32|0x00000043
+  ## If set, framebuffer memory will be reserved and mapped in the system RAM
+  gArmPlatformTokenSpaceGuid.PcdArmLcdDdrFrameBufferBase|0x0|UINT64|0x00000044
+
   ## PL180 MCI
   gArmPlatformTokenSpaceGuid.PcdPL180SysMciRegAddress|0x00000000|UINT32|0x00000028
   gArmPlatformTokenSpaceGuid.PcdPL180MciBaseAddress|0x00000000|UINT32|0x00000029
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'