[BOOT] Add boot library stubs

BOOT/ENVIRON/INC/bootlib.h

@@ -0,0 +1,37 @@
+/*++
+
+Copyright (c) 2024, Quinn Stephens.
+Provided under the BSD 3-Clause license.
+
+Module Name:
+
+   bootlib.h
+
+Abstract:
+
+   Boot library definitions.
+
+--*/
+
+#ifndef _BOOTLIB_H
+#define _BOOTLIB_H
+
+#include <nt.h>
+#include "bootmgr.h"
+
+typedef struct {
+    ULONG Flags;
+} BOOT_LIBRARY_PARAMETERS, *PBOOT_LIBRARY_PARAMETERS;
+
+NTSTATUS
+BlInitializeLibrary (
+    IN PBOOT_INPUT_PARAMETERS InputParameters,
+    IN PBOOT_LIBRARY_PARAMETERS LibraryParameters
+    );
+
+NTSTATUS
+BlDestroyLibrary (
+    VOID
+    );
+
+#endif

BOOT/ENVIRON/INC/ntdef.h

@@ -50,6 +50,9 @@ Abstract:
     #define NTAPI
 #endif
 
+#undef NULL
+#define NULL ((VOID *)0)
+
 //
 // Basic types.
 //