diff --git a/hll/DrawPluginManager.c b/hll/DrawPluginManager.c
new file mode 100644
index 0000000..58cb689
--- /dev/null
+++ b/hll/DrawPluginManager.c
@@ -0,0 +1,26 @@
+/* Copyright (C) 2019 Nunuhara Cabbage <nunuhara@haniwa.technology>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://gnu.org/licenses/>.
+ */
+
+#include "hll.h"
+
+hll_warn_unimplemented(DrawPluginManager, Load, 1);
+hll_warn_unimplemented(DrawPluginManager, IsLoad, 1);
+
+hll_deflib(DrawPluginManager) {
+	hll_export(Load),
+	hll_export(IsLoad),
+	NULL
+};
diff --git a/meson.build b/meson.build
index fb16538..d7531e7 100644
--- a/meson.build
+++ b/meson.build
@@ -17,7 +17,8 @@ xsystem4 = ['ald.c',
             'system4.c',
             'vm.c',
 ]
-hll_libs = ['hll/Math.c',
+hll_libs = ['hll/DrawPluginManager.c',
+            'hll/Math.c',
             'hll/MsgLogManager.c',
             'hll/OutputLog.c',
             'hll/SACT2.c',
diff --git a/vm.c b/vm.c
index b569993..5bef789 100644
--- a/vm.c
+++ b/vm.c
@@ -367,6 +367,7 @@ static void system_call(int32_t code)
 		break;
 	default:
 		WARNING("Unimplemented syscall: 0x%X", code);
+		vm_stack_trace();
 	}
 }
 
@@ -1069,12 +1070,14 @@ static void vm_execute(void)
 	}
 }
 
+extern struct library lib_DrawPluginManager;
 extern struct library lib_Math;
 extern struct library lib_MsgLogManager;
 extern struct library lib_OutputLog;
 extern struct library lib_SACT2;
 
 struct library *libraries[] = {
+	&lib_DrawPluginManager,
 	&lib_Math,
 	&lib_MsgLogManager,
 	&lib_OutputLog,