[BOOT:BOOTMGR] Begin work on BCD support

Added stub for BmOpenDataStore()

BOOT/ENVIRON/APP/BOOTMGR/bcd.c

@@ -0,0 +1,56 @@
+/*++
+
+Copyright (c) 2024, Quinn Stephens.
+Provided under the BSD 3-Clause license.
+
+Module Name:
+
+   bcd.c
+
+Abstract:
+
+   BCD (Boot Configuration Data, aka Boot Data Store) routines.
+
+--*/
+
+#include "bootlib.h"
+
+NTSTATUS
+BmOpenDataStore (
+    IN OUT PHANDLE DataStore
+    )
+
+/*++
+
+Routine Description:
+
+    Opens the boot configuration data store.
+
+Arguments:
+
+    DataStore - pointer to memory to put the data store handle in.
+
+Return Value:
+
+    STATUS_SUCCESS if successful,
+    Other NTSTATUS value on failure.
+
+--*/
+
+{
+    *DataStore = INVALID_HANDLE_VALUE;
+
+/*
+    NTSTATUS Status;
+    PBOOT_DEVICE Device;
+    PWSTR FilePath;
+    BOOLEAN FilePathSet;
+
+    Device = NULL;
+    FilePath = NULL;
+    FilePathSet = FALSE;
+
+    return BmGetDataStorePath(&Device, &FilePath, &FilePathSet);
+*/
+    return STATUS_SUCCESS;
+}

BOOT/ENVIRON/APP/BOOTMGR/bootmgr.c

@@ -41,6 +41,7 @@ Return Value:
 {
     NTSTATUS Status;
     BOOT_LIBRARY_PARAMETERS LibraryParameters;
+    HANDLE DataStore;
 
     LibraryParameters.Flags = 0;
 
@@ -53,6 +54,11 @@ Return Value:
         goto Exit;
     }
 
+    //
+    // Open the boot data store.
+    //
+    (VOID)BmOpenDataStore(&DataStore);
+
 Exit:
     BlDestroyLibrary();
     return Status;

BOOT/ENVIRON/INC/bootmgr.h

@@ -244,6 +244,11 @@ typedef struct {
     BOOT_DEVICE Device;
 } BCDE_DEVICE, *PBCDE_DEVICE;
 
+NTSTATUS
+BmOpenDataStore (
+    IN OUT PHANDLE DataStore
+    );
+
 NTSTATUS
 BmMain (
     IN PBOOT_INPUT_PARAMETERS InputParameters