OvmfPkg/PlatformDebugLibIoPort: Add new APIs

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1395

Add new APIs' implementation (DebugVPrint, DebugBPrint)
in the DebugLib instance. These APIs would expose print
routines with VaList parameter and BaseList parameter.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>

OvmfPkg/Library/PlatformDebugLibIoPort/DebugLib.c

@@ -2,7 +2,7 @@
   Base Debug library instance for QEMU debug port.
   It uses PrintLib to send debug messages to a fixed I/O port.
 
-  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2012, Red Hat, Inc.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -29,6 +29,12 @@
 //
 #define MAX_DEBUG_MESSAGE_LENGTH  0x100
 
+//
+// VA_LIST can not initialize to NULL for all compiler, so we use this to
+// indicate a null VA_LIST
+//
+VA_LIST     mVaListNull;
+
 /**
   Prints a debug message to the debug output device if the specified error level is enabled.
 
@@ -51,9 +57,41 @@ DebugPrint (
   IN  CONST CHAR8  *Format,
   ...
   )
+{
+  VA_LIST         Marker;
+
+  VA_START (Marker, Format);
+  DebugVPrint (ErrorLevel, Format, Marker);
+  VA_END (Marker);
+}
+
+
+/**
+  Prints a debug message to the debug output device if the specified
+  error level is enabled base on Null-terminated format string and a
+  VA_LIST argument list or a BASE_LIST argument list.
+
+  If any bit in ErrorLevel is also set in DebugPrintErrorLevelLib function
+  GetDebugPrintErrorLevel (), then print the message specified by Format and
+  the associated variable argument list to the debug output device.
+
+  If Format is NULL, then ASSERT().
+
+  @param  ErrorLevel      The error level of the debug message.
+  @param  Format          Format string for the debug message to print.
+  @param  VaListMarker    VA_LIST marker for the variable argument list.
+  @param  BaseListMarker  BASE_LIST marker for the variable argument list.
+
+**/
+VOID
+DebugPrintMarker (
+  IN  UINTN         ErrorLevel,
+  IN  CONST CHAR8   *Format,
+  IN  VA_LIST       VaListMarker,
+  IN  BASE_LIST     BaseListMarker
+  )
 {
   CHAR8    Buffer[MAX_DEBUG_MESSAGE_LENGTH];
-  VA_LIST  Marker;
   UINTN    Length;
 
   //
@@ -72,9 +110,11 @@ DebugPrint (
   //
   // Convert the DEBUG() message to an ASCII String
   //
-  VA_START (Marker, Format);
+  if (BaseListMarker == NULL) {
-  Length = AsciiVSPrint (Buffer, sizeof (Buffer), Format, Marker);
+    Length = AsciiVSPrint (Buffer, sizeof (Buffer), Format, VaListMarker);
-  VA_END (Marker);
+  } else {
+    Length = AsciiBSPrint (Buffer, sizeof (Buffer), Format, BaseListMarker);
+  }
 
   //
   // Send the print string to the debug I/O port
@@ -83,6 +123,62 @@ DebugPrint (
 }
 
 
+/**
+  Prints a debug message to the debug output device if the specified
+  error level is enabled.
+
+  If any bit in ErrorLevel is also set in DebugPrintErrorLevelLib function
+  GetDebugPrintErrorLevel (), then print the message specified by Format and
+  the associated variable argument list to the debug output device.
+
+  If Format is NULL, then ASSERT().
+
+  @param  ErrorLevel    The error level of the debug message.
+  @param  Format        Format string for the debug message to print.
+  @param  VaListMarker  VA_LIST marker for the variable argument list.
+
+**/
+VOID
+EFIAPI
+DebugVPrint (
+  IN  UINTN         ErrorLevel,
+  IN  CONST CHAR8   *Format,
+  IN  VA_LIST       VaListMarker
+  )
+{
+  DebugPrintMarker (ErrorLevel, Format, VaListMarker, NULL);
+}
+
+
+/**
+  Prints a debug message to the debug output device if the specified
+  error level is enabled.
+  This function use BASE_LIST which would provide a more compatible
+  service than VA_LIST.
+
+  If any bit in ErrorLevel is also set in DebugPrintErrorLevelLib function
+  GetDebugPrintErrorLevel (), then print the message specified by Format and
+  the associated variable argument list to the debug output device.
+
+  If Format is NULL, then ASSERT().
+
+  @param  ErrorLevel      The error level of the debug message.
+  @param  Format          Format string for the debug message to print.
+  @param  BaseListMarker  BASE_LIST marker for the variable argument list.
+
+**/
+VOID
+EFIAPI
+DebugBPrint (
+  IN  UINTN         ErrorLevel,
+  IN  CONST CHAR8   *Format,
+  IN  BASE_LIST     BaseListMarker
+  )
+{
+  DebugPrintMarker (ErrorLevel, Format, mVaListNull, BaseListMarker);
+}
+
+
 /**
   Prints an assert message containing a filename, line number, and description.
   This may be followed by a breakpoint or a dead loop.