[PATCH 2/3] ArmPlatformPkg: PrePeiCore: write early hello message to the serial port

["Oliver Steffen" <osteffen@redhat.com>]

From: Laszlo Ersek <lersek@redhat.com>

Print the early hello message to the serial port.

The FixedPcdGetSize() macro expands to an integer constant, therefore an
optimizing compiler can eliminate the new code, if the platform DSC
doesn't override the empty string (size=1) default of
PcdEarlyHelloMessage.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
---
 ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf  | 2 ++
 ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf | 2 ++
 ArmPlatformPkg/PrePeiCore/PrePeiCore.h          | 1 +
 ArmPlatformPkg/PrePeiCore/MainMPCore.c          | 7 +++++++
 ArmPlatformPkg/PrePeiCore/MainUniCore.c         | 7 +++++++
 5 files changed, 19 insertions(+)

diff --git a/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf b/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf
index a5b4722459d1..ea7b220bc831 100644
--- a/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf
+++ b/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf
@@ -66,6 +66,8 @@ [FixedPcd]
   gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize
   gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize
 
+  gArmPlatformTokenSpaceGuid.PcdEarlyHelloMessage
+
   gArmTokenSpaceGuid.PcdGicDistributorBase
   gArmTokenSpaceGuid.PcdGicInterruptInterfaceBase
   gArmTokenSpaceGuid.PcdGicSgiIntId
diff --git a/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf b/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
index 466a2b01c384..29fb8737cb2f 100644
--- a/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
+++ b/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
@@ -64,4 +64,6 @@ [FixedPcd]
   gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize
   gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize
 
+  gArmPlatformTokenSpaceGuid.PcdEarlyHelloMessage
+
   gEfiMdeModulePkgTokenSpaceGuid.PcdInitValueInTempStack
diff --git a/ArmPlatformPkg/PrePeiCore/PrePeiCore.h b/ArmPlatformPkg/PrePeiCore/PrePeiCore.h
index 0345dd7bdd2a..ae8302becda2 100644
--- a/ArmPlatformPkg/PrePeiCore/PrePeiCore.h
+++ b/ArmPlatformPkg/PrePeiCore/PrePeiCore.h
@@ -16,6 +16,7 @@
 #include <Library/DebugLib.h>
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
+#include <Library/SerialPortLib.h>
 
 #include <PiPei.h>
 #include <Ppi/TemporaryRamSupport.h>
diff --git a/ArmPlatformPkg/PrePeiCore/MainMPCore.c b/ArmPlatformPkg/PrePeiCore/MainMPCore.c
index b5d0d3a6442f..21c9d5f6da8f 100644
--- a/ArmPlatformPkg/PrePeiCore/MainMPCore.c
+++ b/ArmPlatformPkg/PrePeiCore/MainMPCore.c
@@ -116,6 +116,13 @@ PrimaryMain (
   UINTN                   TemporaryRamBase;
   UINTN                   TemporaryRamSize;
 
+  if (FixedPcdGetSize (PcdEarlyHelloMessage) > 1) {
+    SerialPortWrite (
+      FixedPcdGetPtr (PcdEarlyHelloMessage),
+      FixedPcdGetSize (PcdEarlyHelloMessage) - 1
+      );
+  }
+
   CreatePpiList (&PpiListSize, &PpiList);
 
   // Enable the GIC Distributor
diff --git a/ArmPlatformPkg/PrePeiCore/MainUniCore.c b/ArmPlatformPkg/PrePeiCore/MainUniCore.c
index 1c2580eb923b..37560540e14f 100644
--- a/ArmPlatformPkg/PrePeiCore/MainUniCore.c
+++ b/ArmPlatformPkg/PrePeiCore/MainUniCore.c
@@ -29,6 +29,13 @@ PrimaryMain (
   UINTN                   TemporaryRamBase;
   UINTN                   TemporaryRamSize;
 
+  if (FixedPcdGetSize (PcdEarlyHelloMessage) > 1) {
+    SerialPortWrite (
+      FixedPcdGetPtr (PcdEarlyHelloMessage),
+      FixedPcdGetSize (PcdEarlyHelloMessage) - 1
+      );
+  }
+
   CreatePpiList (&PpiListSize, &PpiList);
 
   // Adjust the Temporary Ram as the new Ppi List (Common + Platform Ppi Lists) is created at
-- 
2.37.1