MdeModulePkg/BdsDxe: fall back to a Boot Manager Menu loop before hanging

Under the following scenario:

- no UEFI bootable application available anywhere in the system,
- ... not even for the default platform recovery option,
- no shell is built into the firmware image,
- but UiApp is available in the firmware image,

we should preferably not just hang in BdsEntry() with:

   DEBUG ((EFI_D_ERROR, "[Bds] Unable to boot!\n"));
   CpuDeadLoop ();

while the user sits at the TianoCore logo page, wondering what's going on.
Print an informative message to the console, wait for a keypress, and then
return to the Boot Manager Menu forever.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1515418
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=513
Suggested-by: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>

diff --git a/MdeModulePkg/Universal/BdsDxe/BdsEntry.c b/MdeModulePkg/Universal/BdsDxe/BdsEntry.c
index dccc4909021967cf1bf2cbf4409aaf4cfbc6a3b0..2b24755ac368696f7fd57c7917dcd64614d225ac 100644 (file)
--- a/MdeModulePkg/Universal/BdsDxe/BdsEntry.c
+++ b/MdeModulePkg/Universal/BdsDxe/BdsEntry.c
@@ -685,6 +685,55 @@ BdsAllocateMemoryForPerformanceData (
   }\r
 }\r
 \r
+/**\r
+  Enter an infinite loop of calling the Boot Manager Menu.\r
+\r
+  This is a last resort alternative to BdsEntry() giving up for good. This\r
+  function never returns.\r
+\r
+  @param[in] BootManagerMenu  The EFI_BOOT_MANAGER_LOAD_OPTION located and/or\r
+                              created by the EfiBootManagerGetBootManagerMenu()\r
+                              call in BdsEntry().\r
+**/\r
+VOID\r
+BdsBootManagerMenuLoop (\r
+  IN EFI_BOOT_MANAGER_LOAD_OPTION *BootManagerMenu\r
+  )\r
+{\r
+  EFI_INPUT_KEY Key;\r
+\r
+  //\r
+  // Normally BdsDxe does not print anything to the system console, but this is\r
+  // a last resort -- the end-user will likely not see any DEBUG messages\r
+  // logged in this situation.\r
+  //\r
+  // AsciiPrint() will NULL-check gST->ConOut internally. We check gST->ConIn\r
+  // here to see if it makes sense to request and wait for a keypress.\r
+  //\r
+  if (gST->ConIn != NULL) {\r
+    AsciiPrint (\r
+      "%a: No bootable option or device was found.\n"\r
+      "%a: Press any key to enter the Boot Manager Menu.\n",\r
+      gEfiCallerBaseName,\r
+      gEfiCallerBaseName\r
+      );\r
+    BdsWaitForSingleEvent (gST->ConIn->WaitForKey, 0);\r
+\r
+    //\r
+    // Drain any queued keys.\r
+    //\r
+    while (!EFI_ERROR (gST->ConIn->ReadKeyStroke (gST->ConIn, &Key))) {\r
+      //\r
+      // just throw away Key\r
+      //\r
+    }\r
+  }\r
+\r
+  for (;;) {\r
+    EfiBootManagerBoot (BootManagerMenu);\r
+  }\r
+}\r
+\r
 /**\r
 \r
   Service routine for BdsInstance->Entry(). Devices are connected, the\r
@@ -1088,16 +1137,19 @@ BdsEntry (
     } while (BootSuccess);\r
   }\r
 \r
-  if (BootManagerMenuStatus != EFI_NOT_FOUND) {\r
-    EfiBootManagerFreeLoadOption (&BootManagerMenu);\r
-  }\r
-\r
   if (!BootSuccess) {\r
     LoadOptions = EfiBootManagerGetLoadOptions (&LoadOptionCount, LoadOptionTypePlatformRecovery);\r
     ProcessLoadOptions (LoadOptions, LoadOptionCount);\r
     EfiBootManagerFreeLoadOptions (LoadOptions, LoadOptionCount);\r
   }\r
 \r
+  //\r
+  // If BootManagerMenu is available, fall back to it indefinitely.\r
+  //\r
+  if (BootManagerMenuStatus != EFI_NOT_FOUND) {\r
+    BdsBootManagerMenuLoop (&BootManagerMenu);\r
+  }\r
+\r
   DEBUG ((EFI_D_ERROR, "[Bds] Unable to boot!\n"));\r
   CpuDeadLoop ();\r
 }\r