Store last booted OS in NVRAM and make it default one on next boot

sdk/xtdk/bltypes.h

@@ -77,7 +77,7 @@ typedef PVOID (*PBL_GET_VIRTUAL_ADDRESS)(IN PXTBL_PAGE_MAPPING PageMap, IN PVOID
 typedef EFI_STATUS (*PBL_INITIALIZE_ENTROPY)(PULONGLONG RNGBuffer);
 typedef VOID (*PBL_INITIALIZE_PAGE_MAP)(OUT PXTBL_PAGE_MAPPING PageMap, IN SHORT PageMapLevel, IN PAGE_SIZE PageSize);
 typedef EFI_STATUS (*PBL_INSTALL_XT_PROTOCOL)(IN PVOID Interface, IN PEFI_GUID Guid);
-typedef EFI_STATUS (*PBL_INVOKE_BOOT_PROTOCOL)(IN PLIST_ENTRY OptionsList);
+typedef EFI_STATUS (*PBL_INVOKE_BOOT_PROTOCOL)(IN PWCHAR ShortName, IN PLIST_ENTRY OptionsList);
 typedef EFI_STATUS (*PBL_LOCATE_PROTOCOL_HANDLES)(OUT PEFI_HANDLE *Handles, OUT PUINT_PTR Count, IN PEFI_GUID ProtocolGuid);
 typedef EFI_STATUS (*PBL_LOAD_EFI_IMAGE)(IN PEFI_DEVICE_PATH_PROTOCOL DevicePath, IN PVOID ImageData, IN SIZE_T ImageSize, OUT PEFI_HANDLE ImageHandle);
 typedef EFI_STATUS (*PBL_MAP_EFI_MEMORY)(IN OUT PXTBL_PAGE_MAPPING PageMap, IN OUT PVOID *MemoryMapAddress, IN PBL_GET_MEMTYPE_ROUTINE GetMemoryTypeRoutine);
@@ -146,6 +146,7 @@ typedef struct _XTBL_BOOT_PARAMETERS
 typedef struct _XTBL_BOOTMENU_ITEM
 {
     PWCHAR EntryName;
+    PWCHAR ShortName;
     PLIST_ENTRY Options;
 } XTBL_BOOTMENU_ITEM, *PXTBL_BOOTMENU_ITEM;
 

xtldr/includes/xtldr.h

@@ -207,7 +207,8 @@ BlInstallProtocol(IN PVOID Interface,
 
 XTCDECL
 EFI_STATUS
-BlInvokeBootProtocol(IN PLIST_ENTRY OptionsList);
+BlInvokeBootProtocol(IN PWCHAR ShortName,
+                     IN PLIST_ENTRY OptionsList);
 
 XTCDECL
 EFI_STATUS

xtldr/textui.c

@@ -135,7 +135,8 @@ BlDisplayBootMenu()
                     BlConsolePrint(L"Booting '%S' now...\n", MenuEntries[HighligtedEntryId].EntryName);
 
                     /* Boot the highlighted (chosen) OS */
-                    Status = BlInvokeBootProtocol(MenuEntries[HighligtedEntryId].Options);
+                    Status = BlInvokeBootProtocol(MenuEntries[HighligtedEntryId].ShortName,
+                                                  MenuEntries[HighligtedEntryId].Options);
                     if(Status != STATUS_SUCCESS)
                     {
                         /* Failed to boot OS */
@@ -279,7 +280,8 @@ BlDisplayBootMenu()
                     TimeOut = -1;
 
                     /* Boot the highlighted (default) OS */
-                    Status = BlInvokeBootProtocol(MenuEntries[HighligtedEntryId].Options);
+                    Status = BlInvokeBootProtocol(MenuEntries[HighligtedEntryId].ShortName,
+                                                  MenuEntries[HighligtedEntryId].Options);
                     if(Status != STATUS_SUCCESS)
                     {
                         /* Failed to boot OS */

xtldr/xtldr.c

@@ -94,12 +94,14 @@ BlInitializeBootMenuList(OUT PXTBL_BOOTMENU_ITEM MenuEntries,
                          OUT PULONG EntriesCount,
                          OUT PULONG DefaultId)
 {
-    PWCHAR DefaultMenuEntry, MenuEntryName;
+    EFI_GUID VendorGuid = XT_BOOT_LOADER_PROTOCOL_GUID;
+    PWCHAR DefaultMenuEntry, LastBooted, MenuEntryName;
     PLIST_ENTRY MenuEntrySectionList, MenuEntryList;
     PXTBL_CONFIG_SECTION MenuEntrySection;
     PXTBL_CONFIG_ENTRY MenuEntryOption;
-    PXTBL_BOOTMENU_ITEM OsList;
     ULONG DefaultOS, NumberOfEntries;
+    PXTBL_BOOTMENU_ITEM OsList;
+    EFI_STATUS Status;
 
     /* Set default values */
     DefaultOS = 0;
@@ -109,6 +111,20 @@ BlInitializeBootMenuList(OUT PXTBL_BOOTMENU_ITEM MenuEntries,
     /* Get default menu entry from configuration */
     DefaultMenuEntry = BlGetConfigValue(L"DEFAULT");
 
+    /* Check if configuration allows to use last booted OS */
+    if(RtlCompareWideStringInsensitive(BlGetConfigValue(L"KEEPLASTBOOT"), L"TRUE", 0) == 0)
+    {
+        /* Attempt to get last booted Operating System from NVRAM */
+        Status = BlGetEfiVariable(&VendorGuid, L"XtLdrLastBootOS", (PVOID*)&LastBooted);
+        if(Status == STATUS_EFI_SUCCESS)
+        {
+            /* Set default menu entry to last booted OS */
+            DefaultMenuEntry = LastBooted;
+        }
+        BlDebugPrint(L"Last booted OS: '%S' - '%S'\n", LastBooted, DefaultMenuEntry);
+        BlSleepExecution(5000);
+    }
+
     /* Iterate through all menu sections */
     MenuEntrySectionList = BlpMenuList->Flink;
     while(MenuEntrySectionList != BlpMenuList)
@@ -146,6 +162,7 @@ BlInitializeBootMenuList(OUT PXTBL_BOOTMENU_ITEM MenuEntries,
 
         /* Add OS to the boot menu list */
         OsList[NumberOfEntries].EntryName = MenuEntryName;
+        OsList[NumberOfEntries].ShortName = MenuEntrySection->SectionName;
         OsList[NumberOfEntries].Options = &MenuEntrySection->Options;
 
         /* Get next menu entry */
@@ -162,6 +179,9 @@ BlInitializeBootMenuList(OUT PXTBL_BOOTMENU_ITEM MenuEntries,
 /**
  * Loads all necessary modules and invokes boot protocol.
  *
+ * @param ShortName
+ *        Supplies a pointer to a short name of the chosen boot menu entry.
+ *
  * @param OptionsList
  *        Supplies a pointer to list of options associated with chosen boot menu entry.
  *
@@ -171,8 +191,10 @@ BlInitializeBootMenuList(OUT PXTBL_BOOTMENU_ITEM MenuEntries,
  */
 XTCDECL
 EFI_STATUS
-BlInvokeBootProtocol(IN PLIST_ENTRY OptionsList)
+BlInvokeBootProtocol(IN PWCHAR ShortName,
+                     IN PLIST_ENTRY OptionsList)
 {
+    EFI_GUID VendorGuid = XT_BOOT_LOADER_PROTOCOL_GUID;
     XTBL_BOOT_PARAMETERS BootParameters;
     PXTBL_BOOT_PROTOCOL BootProtocol;
     PLIST_ENTRY OptionsListEntry;
@@ -289,6 +311,21 @@ BlInvokeBootProtocol(IN PLIST_ENTRY OptionsList)
         return Status;
     }
 
+    /* Check if chosen operating system should be saved */
+    if(RtlCompareWideStringInsensitive(BlGetConfigValue(L"KEEPLASTBOOT"), L"TRUE", 0) == 0)
+    {
+        /* Save chosen operating system in NVRAM */
+        Status = BlSetEfiVariable(&VendorGuid, L"XtLdrLastBootOS", (PVOID)ShortName, RtlWideStringLength(ShortName, 0) * sizeof(WCHAR));
+        if(Status != STATUS_EFI_SUCCESS)
+        {
+            /* Failed to save chosen Operating System */
+            BlDebugPrint(L"WARNING: Failed to save chosen Operating System in NVRAM (Status Code: 0x%zX)\n", Status);
+        }
+
+        BlDebugPrint(L"Now setting OS: '%S'\n", ShortName);
+        BlSleepExecution(5000);
+    }
+
     /* Boot Operating System */
     return BootProtocol->BootSystem(&BootParameters);
 }