[PATCH 1/3] ArmPlatformPkg: introduce fixed PCD for early hello message

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

From: Laszlo Ersek <lersek@redhat.com>

Add a PCD for defining a hello message that gets printed to the serial port
very early in the boot process, regardless of debug masks. This is useful
for debugging boot problems (especially in virtual machines) and informs
interactive users that the firmware is running.

If a platform doesn't want this feature, it should stick with the default
empty string.

Singed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
---
 ArmPlatformPkg/ArmPlatformPkg.dec | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/ArmPlatformPkg/ArmPlatformPkg.dec b/ArmPlatformPkg/ArmPlatformPkg.dec
index dd6e78f62aa1..ac726417cbe7 100644
--- a/ArmPlatformPkg/ArmPlatformPkg.dec
+++ b/ArmPlatformPkg/ArmPlatformPkg.dec
@@ -122,6 +122,13 @@ [PcdsFixedAtBuild.common]
   ## If set, this will swap settings for HDLCD RED_SELECT and BLUE_SELECT registers
   gArmPlatformTokenSpaceGuid.PcdArmHdLcdSwapBlueRedSelect|FALSE|BOOLEAN|0x00000045
 
+  #
+  # Early hello message (ASCII string), printed to the serial port.
+  # If set to the empty string, nothing is printed.
+  # Otherwise, a trailing CRLF should be specified explicitly.
+  #
+  gArmPlatformTokenSpaceGuid.PcdEarlyHelloMessage|""|VOID*|0x00000100
+
 [PcdsFixedAtBuild.common,PcdsDynamic.common]
   ## PL031 RealTimeClock
   gArmPlatformTokenSpaceGuid.PcdPL031RtcBase|0x0|UINT32|0x00000024
-- 
2.37.1