[edk2-devel] PATCH v3 1/3 MdeModulePkg: TerminalDxe: set xterm resolution on mode change

["Paweł Poławski" <ppolawsk@redhat.com>]

From: Laszlo Ersek <lersek@redhat.com>

TerminalDxe driver can send xterm control sequences.
Reference: <http://rtfm.etla.org/xterm/ctlseq.html>

This way it can trigger client window resize (xterm,
gnome-terminal etc.) accordingly, to a specified number
of rows and columns. It improves user experience
when handling text mode based operations.

New PcdResizeXterm config switch has been added to enable
or disable this behaviour.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Pawel Polawski: Updated commit message for re-submission

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>

Signed-off-by: Paweł Poławski <ppolawsk@redhat.com>
---
 MdeModulePkg/MdeModulePkg.dec                               |  4 +++
 MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf  |  2 ++
 MdeModulePkg/Universal/Console/TerminalDxe/TerminalConOut.c | 29 ++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 9605c617b7a8..76007e0af42a 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -2107,6 +2107,10 @@ [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
   # @Prompt The shared bit mask when Intel Tdx is enabled.
   gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask|0x0|UINT64|0x10000025
 
+  ## Controls whether TerminalDxe outputs an XTerm resize sequence on terminal
+  #  mode change.
+  gEfiMdeModulePkgTokenSpaceGuid.PcdResizeXterm|FALSE|BOOLEAN|0x00010080
+
 [PcdsPatchableInModule]
   ## Specify memory size with page number for PEI code when
   #  Loading Module at Fixed Address feature is enabled.
diff --git a/MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf b/MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf
index b2a8aeba8510..eff625346539 100644
--- a/MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf
+++ b/MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf
@@ -55,6 +55,7 @@ [LibraryClasses]
   DebugLib
   PcdLib
   BaseLib
+  PrintLib
 
 [Guids]
   ## SOMETIMES_PRODUCES ## Variable:L"ConInDev"
@@ -87,6 +88,7 @@ [Protocols]
 [Pcd]
   gEfiMdePkgTokenSpaceGuid.PcdDefaultTerminalType           ## SOMETIMES_CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdErrorCodeSetVariable    ## CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdResizeXterm             ## CONSUMES
 
 # [Event]
 # # Relative timer event set by UnicodeToEfiKey(), used to be one 2 seconds input timeout.
diff --git a/MdeModulePkg/Universal/Console/TerminalDxe/TerminalConOut.c b/MdeModulePkg/Universal/Console/TerminalDxe/TerminalConOut.c
index 7809869e7d49..496849458db4 100644
--- a/MdeModulePkg/Universal/Console/TerminalDxe/TerminalConOut.c
+++ b/MdeModulePkg/Universal/Console/TerminalDxe/TerminalConOut.c
@@ -7,6 +7,8 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
+#include <Library/PrintLib.h>
+
 #include "Terminal.h"
 
 //
@@ -80,6 +82,15 @@ CHAR16  mSetCursorPositionString[] = { ESC, '[', '0', '0', ';', '0', '0', 'H', 0
 CHAR16  mCursorForwardString[]     = { ESC, '[', '0', '0', 'C', 0 };
 CHAR16  mCursorBackwardString[]    = { ESC, '[', '0', '0', 'D', 0 };
 
+//
+// Note that this is an ASCII format string, taking two INT32 arguments:
+// rows, columns.
+//
+// A %d (INT32) format specification can expand to at most 11 characters.
+//
+CHAR8  mResizeTextAreaFormatString[] = "\x1B[8;%d;%dt";
+#define RESIZE_SEQ_SIZE  (sizeof mResizeTextAreaFormatString + 2 * (11 - 2))
+
 //
 // Body of the ConOut functions
 //
@@ -498,6 +509,24 @@ TerminalConOutSetMode (
     return EFI_DEVICE_ERROR;
   }
 
+  if (PcdGetBool (PcdResizeXterm)) {
+    CHAR16  ResizeSequence[RESIZE_SEQ_SIZE];
+
+    UnicodeSPrintAsciiFormat (
+      ResizeSequence,
+      sizeof ResizeSequence,
+      mResizeTextAreaFormatString,
+      (INT32)TerminalDevice->TerminalConsoleModeData[ModeNumber].Rows,
+      (INT32)TerminalDevice->TerminalConsoleModeData[ModeNumber].Columns
+      );
+    TerminalDevice->OutputEscChar = TRUE;
+    Status                        = This->OutputString (This, ResizeSequence);
+    TerminalDevice->OutputEscChar = FALSE;
+    if (EFI_ERROR (Status)) {
+      return EFI_DEVICE_ERROR;
+    }
+  }
+
   This->Mode->Mode = (INT32)ModeNumber;
 
   Status = This->ClearScreen (This);
-- 
2.39.1