From: Poosapalli, Karunakar
Sent: Wednesday, August 9, 2023 9:59 AM
To: Yao, Jiewen; Gao, Liming; devel@edk2.groups.io
Subject: RE: [edk2-devel] [PATCH] SecurityPkg: DxeTcg2PhysicalPresenceLib for Clear Graphics Screen To unblock and Display TPM messages

From: Yao, Jiewen <jiewen.yao@intel.com>
Sent: Wednesday, August 9, 2023 4:44 AM
To: Poosapalli, Karunakar; Gao, Liming; devel@edk2.groups.io
Cc: Yao, Jiewen
Subject: RE: [edk2-devel] [PATCH] SecurityPkg: DxeTcg2PhysicalPresenceLib for Clear Graphics Screen To unblock and Display TPM messages

 

Thanks & Regards

Karunakar Poosapalli

Firmware Principal Engineer, Client BIOS

Customer BIOS | Dell Core BIOS

CPG Software Engineering | Dell Technologies

Mobile +91 9951902957

Karunakar_poosapalli@Dell.Com

[EXTERNAL EMAIL]

 

Can you please review and share your feedback?

 

 

 

Internal Use - Confidential

 

Patch review for Bugzilla -  https://bugzilla.tianocore.org/show_bug.cgi?id=4462 [bugzilla.tianocore.org]

 

From c537f9c5c9e02c54e27466b96fe33555afccd358 Mon Sep 17 00:00:00 2001

From: Karunakar Poosapalli karunakar_poosapalli@dell.com

Date: Sat, 22 Jul 2023 01:13:44 +0530

Subject: [PATCH] Patch - Enhance Tcg2 to clear graphics before printing the

messages on screen

 

[Background]

Tcg2UserConfirm() Function is used to display any user conformation messages on the console

Function Definition Full path - SecurityPkg\Library\DxeTcg2PhysicalPresenceLib\DxeTcg2PhysicalPresenceLib.c

 

[Issue]

In the current Tcg2UserConfirm() implementation, This function forms a destination string to be displayed on the console and directly Print the message on Console.

 

But there is no logic added to clear the graphics before printing the messages on the screen.

 

There are some scenarios where Tcg messages might have been blocked by some other GUI or messages on Console.

  1. When there are some messages or logos already displayed in the content on the console,

     TCG message will NOT be displayed or corrupted to the End user.

  2. There could be a Custom logo displaying on the screen which actually blocks the screen.

 

[Solution]

  1. As TCG user confirmation is the highest priority and it blocks the POST until the user

     presses the input key. Before TCG messages Print on the console, there should be logic

     added to clear the graphics screen

 

Cc: gaoliming gaoliming@byosoft.com.cn

Cc: Jiewen  Jiewen.yao@intel.com

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4462 [bugzilla.tianocore.org]

Signed-off-by: Karunakar Poosapalli karunakar_poosapalli@dell.com

---

.../DxeTcg2PhysicalPresenceLib.c              | 74 +++++++++++++++++++

.../DxeTcg2PhysicalPresenceLib.inf            |  1 +

2 files changed, 75 insertions(+)

 

diff --git a/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.c b/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.c

index de4f5e583d..bd486f3b5b 100644

--- a/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.c

+++ b/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.c

@@ -251,6 +251,74 @@ Tcg2ExecutePhysicalPresence (

   }

}

 

+/**

+  Clear Graphics Screen To unblock and Display TPM messages 

+

+  @param[in]  VOID

+  @retval     EFI_STATUS

+**/

+EFI_STATUS

+ClearGraphicsScreenToDisplayTpmMessages()

+{

+  EFI_GRAPHICS_OUTPUT_PROTOCOL *Gop;

+  EFI_STATUS Status;

+  EFI_HANDLE                              *HandleBuffer;

+  UINTN                                   NumberOfHandles;

+  UINTN                                   Index;

+  EFI_DEVICE_PATH_PROTOCOL                *GopDevicePath;

+

+  DEBUG((DEBUG_INFO, "ClearGraphicsScreenToDisplayTpmMessages Entry...\n"));

+

+  Status = gBS->LocateHandleBuffer (

+            ByProtocol,

+            &gEfiGraphicsOutputProtocolGuid,

+            NULL,

+            &NumberOfHandles,

+            &HandleBuffer

+            );

+  DEBUG((DEBUG_INFO, "LocateHandleBuffer Status = %r, NumberOfHandles = %x\n", Status, NumberOfHandles));

+

+  if (EFI_ERROR (Status))

+  {

+    return Status;

+  }

+ 

+  for (Index = 0; Index < NumberOfHandles; Index++)

+    {

+      Status = gBS->HandleProtocol (

+                HandleBuffer[Index],

+                &gEfiDevicePathProtocolGuid,

+                (VOID *)&GopDevicePath

+                );

+      DEBUG((DEBUG_INFO, "HandleProtocol GopDevicePath Status = %r, Index = %x\n", Status, Index));

+      if (EFI_ERROR (Status))

+        {

+          continue;

+        }

+

+      Status = gBS->HandleProtocol (

+                HandleBuffer[Index],

+                &gEfiGraphicsOutputProtocolGuid,

+                (VOID **) &Gop

+                );

+      DEBUG((DEBUG_INFO, "HandleProtocol Gop Status = %r, Index = %x\n", Status, Index));

+      if (EFI_ERROR(Status))

+        {

+            continue;

+        }

+

+      // Clear the graphics screen to black

+      Status = Gop->Blt(Gop, NULL, EfiBltVideoFill, 0, 0, 0, 0, Gop->Mode->Info->HorizontalResolution, Gop->Mode->Info->VerticalResolution, 0);

+      DEBUG((DEBUG_INFO, "Gop->Blt Status = %r, Index = %x\n", Status, Index));

+      if (EFI_ERROR(Status)) {

+        continue;

+      }

+    }

+

+  gBS->FreePool (HandleBuffer);

+  DEBUG((DEBUG_INFO, "ClearGraphicsScreenToDisplayTpmMessages Exit...\n"));

+  return Status;

+}

/**

   Read the specified key for user confirmation.

 

@@ -576,6 +644,12 @@ Tcg2UserConfirm (

   BufSize -= StrSize (ConfirmText);

   UnicodeSPrint (ConfirmText + StrLen (ConfirmText), BufSize, TmpStr1, TmpStr2);

 

+  //

+  //Clear Graphics Screen To unblock and Display TPM messages

+  //

+  Status = ClearGraphicsScreenToDisplayTpmMessages();

+  DEBUG((DEBUG_INFO, "ClearGraphicsScreenToDisplayTpmMessages Status = %r\n", Status));

+

   DstStr[80] = L'\0';

   for (Index = 0; Index < StrLen (ConfirmText); Index += 80) {

     StrnCpyS (DstStr, sizeof (DstStr) / sizeof (CHAR16), ConfirmText + Index, sizeof (DstStr) / sizeof (CHAR16) - 1);

diff --git a/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.inf b/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.inf

index e1c7c20d52..de423cfd13 100644

--- a/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.inf

+++ b/SecurityPkg/Library/DxeTcg2PhysicalPresenceLib/DxeTcg2PhysicalPresenceLib.inf

@@ -54,6 +54,7 @@

[Protocols]

   gEfiTcg2ProtocolGuid                 ## SOMETIMES_CONSUMES

   gEdkiiVariableLockProtocolGuid       ## SOMETIMES_CONSUMES

+  gEfiGraphicsOutputProtocolGuid       ## CONSUMES

 

 [Pcd]

   gEfiSecurityPkgTokenSpaceGuid.PcdTcg2PhysicalPresenceFlags       ## SOMETIMES_CONSUMES

--

2.17.0.windows.1

 

 

Internal Use - Confidential