diff --git a/build/tests/os/Makefile b/build/tests/os/Makefile
index 11093b5..9cbfef5 100644
--- a/build/tests/os/Makefile
+++ b/build/tests/os/Makefile
@@ -24,6 +24,7 @@ SUBDIRS =	alarm-1 \
 		sleep-1 \
                 svc-rsa \
                 svc-sha1 \
+		debugLED \
 
 #----------------------------------------------------------------------------
 
diff --git a/build/tests/os/debugLED/ARM7/Makefile b/build/tests/os/debugLED/ARM7/Makefile
new file mode 100644
index 0000000..df38b29
--- /dev/null
+++ b/build/tests/os/debugLED/ARM7/Makefile
@@ -0,0 +1,44 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  TwlSDK - OS - demos - debugLED
+# File:     Makefile
+#
+# Copyright 2007 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Log: $
+# $NoKeywords: $
+#----------------------------------------------------------------------------
+
+SUBDIRS		=
+
+
+#----------------------------------------------------------------------------
+
+#TWL_CODEGEN   =       THUMB
+TWL_PROC      =       ARM7
+
+TARGET_BIN	=	main.axf
+
+SRCS		=	main.c
+
+#SRCDIR		=	# using default
+#LCFILE		=	# using default
+
+include	$(TWLSDK_ROOT)/build/buildtools/commondefs
+
+
+#----------------------------------------------------------------------------
+
+do-build:		$(TARGETS)
+
+
+include	$(TWLSDK_ROOT)/build/buildtools/modulerules
+
+
+#===== End of Makefile =====
diff --git a/build/tests/os/debugLED/ARM7/src/main.c b/build/tests/os/debugLED/ARM7/src/main.c
new file mode 100644
index 0000000..8e41020
--- /dev/null
+++ b/build/tests/os/debugLED/ARM7/src/main.c
@@ -0,0 +1,45 @@
+/*---------------------------------------------------------------------------*
+  Project:  TwlSDK - OS - demos - debugLED
+  File:     main.c
+
+  Copyright 2007 Nintendo.  All rights reserved.
+
+  These coded instructions, statements, and computer programs contain
+  proprietary information of Nintendo of America Inc. and/or Nintendo
+  Company Ltd., and are protected by Federal copyright law.  They may
+  not be disclosed to third parties or copied or duplicated in any form,
+  in whole or in part, without the prior written consent of Nintendo.
+
+  $Log: main.c,v $
+  $NoKeywords: $
+ *---------------------------------------------------------------------------*/
+#include <twl.h>
+
+/*---------------------------------------------------------------------------*
+  Name:         TwlMain
+
+  Description:  main
+
+  Arguments:    None
+
+  Returns:      None
+ *---------------------------------------------------------------------------*/
+void TwlMain()
+{
+    int i;
+
+    OS_Init();
+
+    OS_Printf("ARM7 starts.\n");
+
+    OS_InitDebugLED();
+    for (i = 0; i < 0x100; i++)
+    {
+        OS_SetDebugLED((u8)i);
+        SVC_WaitByLoop(0x20000);
+    }
+
+    // done
+    OS_TPrintf("\nARM7 ends.\n");
+    OS_Terminate();
+}
diff --git a/build/tests/os/debugLED/ARM9/Makefile b/build/tests/os/debugLED/ARM9/Makefile
new file mode 100644
index 0000000..1a74b1a
--- /dev/null
+++ b/build/tests/os/debugLED/ARM9/Makefile
@@ -0,0 +1,43 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  TwlSDK - OS - demos - debugLED
+# File:     Makefile
+#
+# Copyright 2007 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Log: $
+# $NoKeywords: $
+#----------------------------------------------------------------------------
+
+SUBDIRS		=
+
+
+#----------------------------------------------------------------------------
+
+#TWL_CODEGEN   =       THUMB
+
+TARGET_BIN	=	main.axf
+
+SRCS		=	main.c
+
+#SRCDIR		=	# using default
+#LCFILE		=	# using default
+
+include	$(TWLSDK_ROOT)/build/buildtools/commondefs
+
+
+#----------------------------------------------------------------------------
+
+do-build:		$(TARGETS)
+
+
+include	$(TWLSDK_ROOT)/build/buildtools/modulerules
+
+
+#===== End of Makefile =====
diff --git a/build/tests/os/debugLED/ARM9/src/main.c b/build/tests/os/debugLED/ARM9/src/main.c
new file mode 100644
index 0000000..b441d05
--- /dev/null
+++ b/build/tests/os/debugLED/ARM9/src/main.c
@@ -0,0 +1,50 @@
+/*---------------------------------------------------------------------------*
+  Project:  TwlSDK - OS - demos - debugLED
+  File:     main.c
+
+  Copyright 2007 Nintendo.  All rights reserved.
+
+  These coded instructions, statements, and computer programs contain
+  proprietary information of Nintendo of America Inc. and/or Nintendo
+  Company Ltd., and are protected by Federal copyright law.  They may
+  not be disclosed to third parties or copied or duplicated in any form,
+  in whole or in part, without the prior written consent of Nintendo.
+
+  $Log: main.c,v $
+  $NoKeywords: $
+ *---------------------------------------------------------------------------*/
+#include <twl.h>
+
+//================================================================================
+static void dump(const char *str, void *ptr, u32 length)
+{
+    u8 *data = (u8*)ptr;
+    int i;
+    OS_TPrintf("\n[%s] (%d bytes):\n\t", str, length);
+    for (i = 0; i < length; i++) {
+        OS_TPrintf("%02X", *data++);
+        if ((i & 0xF) == 0xF) OS_TPrintf("\n\t");
+        else    OS_TPrintf(" ");
+    }
+    OS_TPrintf("\n");
+}
+
+/*---------------------------------------------------------------------------*
+  Name:         TwlMain
+
+  Description:  main
+
+  Arguments:    None
+
+  Returns:      None
+ *---------------------------------------------------------------------------*/
+void TwlMain()
+{
+    OS_Init();
+
+    OS_Printf("ARM9 starts.\n");
+
+    // done
+    OS_TPrintf("\nARM9 ends.\n");
+    OS_Terminate();
+}
diff --git a/build/tests/os/debugLED/Makefile b/build/tests/os/debugLED/Makefile
new file mode 100644
index 0000000..078ec37
--- /dev/null
+++ b/build/tests/os/debugLED/Makefile
@@ -0,0 +1,32 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  TwlSDK - build
+# File:     Makefile
+#
+# Copyright 2007 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Log: $
+# $NoKeywords: $
+#----------------------------------------------------------------------------
+
+include	$(TWLSDK_ROOT)/build/buildtools/commondefs
+
+
+#----------------------------------------------------------------------------
+
+SUBDIRS =	\
+            ARM7 \
+            ARM9 \
+
+#----------------------------------------------------------------------------
+
+include	$(TWLSDK_ROOT)/build/buildtools/modulerules
+
+
+#===== End of Makefile =====