[PATCH 1/1] ArmPkg/PlatformBootManagerLib: Add path to boot UEFI Shell over UiApp

["PierreGondois" <pierre.gondois@arm.com>]

From: Pierre Gondois <pierre.gondois@arm.com>

The UEFI Shell is a non-active boot option, at the opposite of UiApp.
If no valid boot option is found, UiApp is selected. UiApp requires a
human interaction. When installing a new EDKII image in CIs or when
scripting is required, this is problematic.

If no valid boot option is discovered, add a path to directly go to
the UEFI Shell where the startup.nsh script is automatically executed.
The UEFI Shell is launched after connecting possible devices, but
before the reset that is meant to automatically make them visible.

The new PcdUefiShellDefaultBootEnable must be set to TRUE to enable
this behaviour. The Pcd is set to false by default.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 ArmPkg/ArmPkg.dec                             |  9 ++-
 .../PlatformBootManagerLib/PlatformBm.c       | 69 ++++++++++++++++++-
 .../PlatformBootManagerLib.inf                |  4 +-
 3 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/ArmPkg/ArmPkg.dec b/ArmPkg/ArmPkg.dec
index f17ba913e6de..2444457ae58a 100644
--- a/ArmPkg/ArmPkg.dec
+++ b/ArmPkg/ArmPkg.dec
@@ -2,7 +2,7 @@
 # ARM processor package.
 #
 # Copyright (c) 2009 - 2010, Apple Inc. All rights reserved.<BR>
-# Copyright (c) 2011 - 2022, ARM Limited. All rights reserved.
+# Copyright (c) 2011 - 2023, ARM Limited. All rights reserved.
 # Copyright (c) 2021, Ampere Computing LLC. All rights reserved.
 #
 #    SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -221,6 +221,13 @@ [PcdsFixedAtBuild.common]
   #
   gArmTokenSpaceGuid.PcdArmDmaDeviceOffset|0x0|UINT64|0x0000044
 
+  #
+  # Boot the Uefi Shell instead of UiApp when no valid boot option is found.
+  # This is useful in CI environment so that startup.nsh can be launched.
+  # The default value is FALSE.
+  #
+  gArmTokenSpaceGuid.PcdUefiShellDefaultBootEnable|FALSE|BOOLEAN|0x0000052
+
 [PcdsFixedAtBuild.common, PcdsPatchableInModule.common]
   gArmTokenSpaceGuid.PcdFdBaseAddress|0|UINT64|0x0000002B
   gArmTokenSpaceGuid.PcdFvBaseAddress|0|UINT64|0x0000002D
diff --git a/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c b/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c
index 2fb1a4aa4fb8..9bdc44d86b54 100644
--- a/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c
+++ b/ArmPkg/Library/PlatformBootManagerLib/PlatformBm.c
@@ -2,7 +2,7 @@
   Implementation for PlatformBootManagerLib library class interfaces.
 
   Copyright (C) 2015-2016, Red Hat, Inc.
-  Copyright (c) 2014 - 2021, ARM Ltd. All rights reserved.<BR>
+  Copyright (c) 2014 - 2023, Arm Ltd. All rights reserved.<BR>
   Copyright (c) 2004 - 2018, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
   Copyright (c) 2021, Semihalf All rights reserved.<BR>
@@ -470,6 +470,61 @@ PlatformRegisterFvBootOption (
   EfiBootManagerFreeLoadOptions (BootOptions, BootOptionCount);
 }
 
+/** Boot a Fv Boot Option.
+ *
+ * This function is useful for booting the UEFI Shell as it is loaded
+ * as a non active boot option.
+ *
+ * @param[in] FileGuid      The File GUID.
+ * @param[in] Description   String describing the Boot Option.
+ */
+STATIC
+VOID
+PlatformBootFvBootOption (
+  IN  CONST EFI_GUID  *FileGuid,
+  IN  CHAR16          *Description
+  )
+{
+  EFI_STATUS                         Status;
+  EFI_BOOT_MANAGER_LOAD_OPTION       NewOption;
+  MEDIA_FW_VOL_FILEPATH_DEVICE_PATH  FileNode;
+  EFI_LOADED_IMAGE_PROTOCOL          *LoadedImage;
+  EFI_DEVICE_PATH_PROTOCOL           *DevicePath;
+
+  Status = gBS->HandleProtocol (
+                  gImageHandle,
+                  &gEfiLoadedImageProtocolGuid,
+                  (VOID **)&LoadedImage
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  EfiInitializeFwVolDevicepathNode (&FileNode, FileGuid);
+  DevicePath = DevicePathFromHandle (LoadedImage->DeviceHandle);
+  ASSERT (DevicePath != NULL);
+  DevicePath = AppendDevicePathNode (
+                 DevicePath,
+                 (EFI_DEVICE_PATH_PROTOCOL *)&FileNode
+                 );
+  ASSERT (DevicePath != NULL);
+
+  Status = EfiBootManagerInitializeLoadOption (
+             &NewOption,
+             LoadOptionNumberUnassigned,
+             LoadOptionTypeBoot,
+             LOAD_OPTION_ACTIVE,
+             Description,
+             DevicePath,
+             NULL,
+             0
+             );
+  ASSERT_EFI_ERROR (Status);
+  FreePool (DevicePath);
+
+  for ( ; ;) {
+    EfiBootManagerBoot (&NewOption);
+  }
+}
+
 STATIC
 VOID
 GetPlatformOptions (
@@ -1075,6 +1130,18 @@ PlatformBootManagerUnableToBoot (
   EfiBootManagerConnectAll ();
   EfiBootManagerRefreshAllBootOption ();
 
+  //
+  // Boot the 'UEFI Shell'. If the Pcd is not set, the UEFI Shell is not
+  // an active boot option and must be manually selected through UiApp
+  // (at least during the fist boot).
+  //
+  if (FixedPcdGetBool (PcdUefiShellDefaultBootEnable)) {
+    PlatformBootFvBootOption (
+      &gUefiShellFileGuid,
+      L"UEFI Shell (default)"
+      );
+  }
+
   //
   // Record the updated number of boot configured boot options
   //
diff --git a/ArmPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf b/ArmPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
index 86751b45f82b..05ed46456cc4 100644
--- a/ArmPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
+++ b/ArmPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
@@ -2,7 +2,7 @@
 #  Implementation for PlatformBootManagerLib library class interfaces.
 #
 #  Copyright (C) 2015-2016, Red Hat, Inc.
-#  Copyright (c) 2014, ARM Ltd. All rights reserved.<BR>
+#  Copyright (c) 2014 - 2023, Arm Ltd. All rights reserved.<BR>
 #  Copyright (c) 2007 - 2014, Intel Corporation. All rights reserved.<BR>
 #  Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
 #
@@ -29,6 +29,7 @@ [Sources]
   PlatformBm.h
 
 [Packages]
+  ArmPkg/ArmPkg.dec
   EmbeddedPkg/EmbeddedPkg.dec
   MdeModulePkg/MdeModulePkg.dec
   MdePkg/MdePkg.dec
@@ -55,6 +56,7 @@ [FeaturePcd]
   gEfiMdePkgTokenSpaceGuid.PcdUgaConsumeSupport
 
 [FixedPcd]
+  gArmTokenSpaceGuid.PcdUefiShellDefaultBootEnable
   gEfiMdeModulePkgTokenSpaceGuid.PcdEmuVariableNvModeEnable
   gEfiMdeModulePkgTokenSpaceGuid.PcdFirmwareVersionString
   gEfiMdePkgTokenSpaceGuid.PcdUartDefaultBaudRate
-- 
2.25.1