OvmfPkg/PlatformBootManagerCommonLib: Set UiApp as an optional boot option

Introduce gUiAppFileGuid: it has the same value of UiApp guid defined in
the .inf file. This is used to register UiApp as a boot entry in the
BootManagerMenu.

This registration is done in PlatformBootManagerBeforeConsole because
it must be done before the hotkeys are registered. This is because
in a system with hotkeys still bound to UiApp, but with firmware disabled,
you can still boot into the latter by hitting ESC or F2 during boot.

UiApp can be enabled/disabled using fw_cfg option FirmwareSetupSupport

Signed-off-by: Luigi Leonardi <leonardi@redhat.com>

Author: luigix25

OvmfPkg/Library/PlatformBootManagerLibLight/PlatformBm.c

@@ -777,6 +777,7 @@ PlatformBootManagerBeforeConsole (
   UINT16         FrontPageTimeout;
   RETURN_STATUS  PcdStatus;
   EFI_STATUS     Status;
+  BOOLEAN        FirmwareSetupEnabled;
 
   //
   // Signal EndOfDxe PI Event
@@ -877,6 +878,22 @@ PlatformBootManagerBeforeConsole (
     Status
     ));
 
+  Status = QemuFwCfgParseBool (
+             "opt/org.tianocore/FirmwareSetupSupport",
+             &FirmwareSetupEnabled
+             );
+
+  if (RETURN_ERROR (Status)) {
+    FirmwareSetupEnabled = TRUE;
+  }
+
+  PlatformRegisterFvBootOption (
+    &gUiAppFileGuid,
+    L"EFI Firmware Setup",
+    LOAD_OPTION_ACTIVE | LOAD_OPTION_CATEGORY_APP,
+    FirmwareSetupEnabled
+    );
+
   //
   // Register platform-specific boot options and keyboard shortcuts.
   //

OvmfPkg/Library/PlatformBootManagerLibLight/PlatformBootManagerLib.inf

@@ -71,6 +71,7 @@
   gEfiGlobalVariableGuid
   gRootBridgesConnectedEventGroupGuid
   gUefiShellFileGuid
+  gUiAppFileGuid
 
 [Protocols]
   gEfiFirmwareVolume2ProtocolGuid