diff --git a/keyboard/ghpad/Makefile.lufa b/keyboard/ghpad/Makefile
similarity index 96%
rename from keyboard/ghpad/Makefile.lufa
rename to keyboard/ghpad/Makefile
index 16bd46ca..4b76788c 100644
--- a/keyboard/ghpad/Makefile.lufa
+++ b/keyboard/ghpad/Makefile
@@ -48,10 +48,17 @@ TOP_DIR = ../..
 TARGET_DIR = .
 
 # project specific files
-SRC +=	keymap.c \
+SRC =	keymap_common.c \
 	matrix.c \
 	led.c
 
+ifdef KEYMAP
+    SRC := keymap_$(KEYMAP).c $(SRC)
+else
+    SRC := keymap_4x6.c $(SRC)
+endif
+
+
 CONFIG_H = config.h
 
 
@@ -93,7 +100,7 @@ ARCH = AVR8
 F_USB = $(F_CPU)
 
 # Interrupt driven control endpoint task(+60)
-#OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
 
 
 # Boot Section Size in *bytes*
@@ -131,7 +138,3 @@ VPATH += $(TOP_DIR)
 include $(TOP_DIR)/protocol/lufa.mk
 include $(TOP_DIR)/common.mk
 include $(TOP_DIR)/rules.mk
-
-plain: OPT_DEFS += -DKEYMAP_PLAIN
-plain: all
-
diff --git a/keyboard/ghpad/keymap.c b/keyboard/ghpad/keymap.c
deleted file mode 100644
index 3b0a272a..00000000
--- a/keyboard/ghpad/keymap.c
+++ /dev/null
@@ -1,157 +0,0 @@
-/*
-Copyright 2012,2013 Jun Wako <wakojun@gmail.com>
-
-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://www.gnu.org/licenses/>.
-*/
-#include <stdint.h>
-#include <stdbool.h>
-#include <avr/pgmspace.h>
-#include "keycode.h"
-#include "action.h"
-#include "action_macro.h"
-#include "report.h"
-#include "host.h"
-#include "print.h"
-#include "debug.h"
-#include "keymap.h"
-#include "keymap_ex.h"
-
-
-/* GHPad keymap definition macro
- */
-#define KEYMAP( \
-    K0A, K0B, K0C, K0D, \
-    K1A, K1B, K1C, K1D, \
-    K2A, K2B, K2C, K2D, \
-    K3A, K3B, K3C, K3D, \
-    K4A, K4B, K4C, K4D, \
-    K5A, K5B, K5C, K5D  \
-) { \
-    { KC_##K0A, KC_##K0B, KC_##K0C, KC_##K0D }, \
-    { KC_##K1A, KC_##K1B, KC_##K1C, KC_##K1D }, \
-    { KC_##K2A, KC_##K2B, KC_##K2C, KC_##K2D }, \
-    { KC_##K3A, KC_##K3B, KC_##K3C, KC_##K3D }, \
-    { KC_##K4A, KC_##K4B, KC_##K4C, KC_##K4D }, \
-    { KC_##K5A, KC_##K5B, KC_##K5C, KC_##K5D }  \
-}
-
-#if defined(KEYMAP_PLAIN)
-    #include "keymap_plain.h"
-#else
-#ifdef KEYMAP_SECTION_ENABLE
-const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] __attribute__ ((section (".keymap.keymaps"))) = {
-#else
-static const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] PROGMEM = {
-#endif
-    /* Keymap 0: Default Layer
-     * ,---------------.
-     * |Num|/  |*  |-  |
-     * |---+---+---+---|
-     * |7  |8  |9  |+  |
-     * |---+---+---|   |
-     * |4  |5  |6  |   |
-     * |---+---+---+---|
-     * |1  |2  |3  |Ent|
-     * |---+---+---|   |
-     * |0  |Up |.  |   |
-     * |---+---+---+---|
-     * |Lef|Dow|Rig|Fn0|
-     * `---------------'
-     */
-    [0] = KEYMAP(
-        NLCK,PSLS,PAST,PMNS, \
-        P7,  P8,  P9,  PPLS, \
-        P4,  P5,  P6,  NO,   \
-        P1,  P2,  P3,  PENT, \
-        P0,  UP,  PDOT,NO,   \
-        LEFT,DOWN,RGHT,FN0),
-    /* Keymap 1: */
-    [1] = KEYMAP(
-        TRNS,TRNS,TRNS,TRNS, \
-        TRNS,TRNS,TRNS,TRNS, \
-        TRNS,TRNS,TRNS,TRNS, \
-        TRNS,TRNS,TRNS,TRNS, \
-        TRNS,TRNS,TRNS,TRNS, \
-        TRNS,TRNS,TRNS,TRNS),
-};
-
-/*
- * Fn action definition
- */
-#ifdef KEYMAP_SECTION_ENABLE
-const uint16_t fn_actions[] __attribute__ ((section (".keymap.fn_actions"))) = {
-#else
-static const uint16_t fn_actions[] PROGMEM = {
-#endif
-    [0] = ACTION_LAYER_MOMENTARY(1)
-};
-#endif
-
-#define KEYMAPS_SIZE    (sizeof(keymaps) / sizeof(keymaps[0]))
-#define FN_ACTIONS_SIZE (sizeof(fn_actions) / sizeof(fn_actions[0]))
-
-#ifdef KEYMAP_EX_ENABLE
-const uint8_t* keymaps_pointer(void) {
-    return (const uint8_t*)keymaps;
-}
-
-const uint16_t* fn_actions_pointer(void) {
-    return fn_actions;
-}
-
-uint16_t keys_count(void) {
-    return KEYMAPS_SIZE * MATRIX_ROWS * MATRIX_COLS;
-}
-
-uint16_t fn_actions_count(void) {
-    return FN_ACTIONS_SIZE;
-}
-#endif
-
-/* translates key to keycode */
-uint8_t keymap_key_to_keycode(uint8_t layer, key_t key)
-{
-    if (layer < KEYMAPS_SIZE) {
-#ifndef KEYMAP_EX_ENABLE
-        return pgm_read_byte(&keymaps[(layer)][(key.row)][(key.col)]);
-#else
-        return eeconfig_read_keymap_key(layer, key.row, key.col);
-#endif
-    } else {
-        // XXX: this may cuaes bootlaoder_jump inconsistent fail.
-        //debug("key_to_keycode: base "); debug_dec(layer); debug(" is invalid.\n");
-        // fall back to layer 0
-#ifndef KEYMAP_EX_ENABLE
-        return pgm_read_byte(&keymaps[0][(key.row)][(key.col)]);
-#else
-        return eeconfig_read_keymap_key(0, key.row, key.col);
-#endif
-    }
-}
-
-/* translates Fn keycode to action */
-action_t keymap_fn_to_action(uint8_t keycode)
-{
-    action_t action;
-    if (FN_INDEX(keycode) < FN_ACTIONS_SIZE) {
-#ifndef KEYMAP_EX_ENABLE
-        action.code = pgm_read_word(&fn_actions[FN_INDEX(keycode)]);
-#else
-        action.code = eeconfig_read_keymap_fn_action(FN_INDEX(keycode));
-#endif
-    } else {
-        action.code = ACTION_NO;
-    }
-    return action;
-}
diff --git a/keyboard/ghpad/keymap_plain.h b/keyboard/ghpad/keymap_4x6.c
similarity index 53%
rename from keyboard/ghpad/keymap_plain.h
rename to keyboard/ghpad/keymap_4x6.c
index b4e2aad3..c70ff7a7 100644
--- a/keyboard/ghpad/keymap_plain.h
+++ b/keyboard/ghpad/keymap_4x6.c
@@ -1,7 +1,10 @@
+#include "keymap_common.h"
+
+// 4x6 Keypad
 #ifdef KEYMAP_SECTION_ENABLE
-const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] __attribute__ ((section (".keymap.keymaps"))) = {
+const uint8_t keymaps[KEYMAPS_COUNT][MATRIX_ROWS][MATRIX_COLS] __attribute__ ((section (".keymap.keymaps"))) = {
 #else
-static const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] PROGMEM = {
+const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] PROGMEM = {
 #endif
     /* Keymap 0: Default Layer
      * ,---------------.
@@ -31,8 +34,18 @@ static const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] PROGMEM = {
  * Fn action definition
  */
 #ifdef KEYMAP_SECTION_ENABLE
-const uint16_t fn_actions[] __attribute__ ((section (".keymap.fn_actions"))) = {
+const uint16_t fn_actions[FN_ACTIONS_COUNT] __attribute__ ((section (".keymap.fn_actions"))) = {
 #else
-static const uint16_t fn_actions[] PROGMEM = {
+const uint16_t fn_actions[] PROGMEM = {
 #endif
 };
+
+#ifdef KEYMAP_EX_ENABLE
+uint16_t keys_count(void) {
+    return sizeof(keymaps) / sizeof(keymaps[0]) * MATRIX_ROWS * MATRIX_COLS;
+}
+
+uint16_t fn_actions_count(void) {
+    return sizeof(fn_actions) / sizeof(fn_actions[0]);
+}
+#endif
diff --git a/keyboard/ghpad/keymap_arrow.c b/keyboard/ghpad/keymap_arrow.c
new file mode 100644
index 00000000..5e00ace3
--- /dev/null
+++ b/keyboard/ghpad/keymap_arrow.c
@@ -0,0 +1,60 @@
+#include "keymap_common.h"
+
+// Keypad with Arrow
+#ifdef KEYMAP_SECTION_ENABLE
+const uint8_t keymaps[KEYMAPS_COUNT][MATRIX_ROWS][MATRIX_COLS] __attribute__ ((section (".keymap.keymaps"))) = {
+#else
+const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS] PROGMEM = {
+#endif
+    /* Keymap 0: Default Layer
+     * ,---------------.
+     * |Num|/  |*  |-  |
+     * |---+---+---+---|
+     * |7  |8  |9  |+  |
+     * |---+---+---|   |
+     * |4  |5  |6  |   |
+     * |---+---+---+---|
+     * |1  |2  |3  |Ent|
+     * |---+---+---|   |
+     * |0  |Up |.  |   |
+     * |---+---+---+---|
+     * |Lef|Dow|Rig|Fn0|
+     * `---------------'
+     */
+    [0] = KEYMAP(
+        NLCK,PSLS,PAST,PMNS, \
+        P7,  P8,  P9,  PPLS, \
+        P4,  P5,  P6,  NO,   \
+        P1,  P2,  P3,  PENT, \
+        P0,  UP,  PDOT,NO,   \
+        LEFT,DOWN,RGHT,FN0),
+    /* Keymap 1: */
+    [1] = KEYMAP(
+        TRNS,TRNS,TRNS,TRNS, \
+        TRNS,TRNS,TRNS,TRNS, \
+        TRNS,TRNS,TRNS,TRNS, \
+        TRNS,TRNS,TRNS,TRNS, \
+        TRNS,TRNS,TRNS,TRNS, \
+        TRNS,TRNS,TRNS,TRNS),
+};
+
+/*
+ * Fn action definition
+ */
+#ifdef KEYMAP_SECTION_ENABLE
+const uint16_t fn_actions[FN_ACTIONS_COUNT] __attribute__ ((section (".keymap.fn_actions"))) = {
+#else
+const uint16_t fn_actions[] PROGMEM = {
+#endif
+    [0] = ACTION_LAYER_MOMENTARY(1)
+};
+
+#ifdef KEYMAP_EX_ENABLE
+uint16_t keys_count(void) {
+    return sizeof(keymaps) / sizeof(keymaps[0]) * MATRIX_ROWS * MATRIX_COLS;
+}
+
+uint16_t fn_actions_count(void) {
+    return sizeof(fn_actions) / sizeof(fn_actions[0]);
+}
+#endif
diff --git a/keyboard/ghpad/keymap_common.c b/keyboard/ghpad/keymap_common.c
new file mode 100644
index 00000000..ae934eea
--- /dev/null
+++ b/keyboard/ghpad/keymap_common.c
@@ -0,0 +1,49 @@
+/*
+Copyright 2012,2013 Jun Wako <wakojun@gmail.com>
+
+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://www.gnu.org/licenses/>.
+*/
+#include "keymap_common.h"
+
+/* translates key to keycode */
+uint8_t keymap_key_to_keycode(uint8_t layer, key_t key)
+{
+#ifndef KEYMAP_EX_ENABLE
+    return pgm_read_byte(&keymaps[(layer)][(key.row)][(key.col)]);
+#else
+    return eeconfig_read_keymap_key(layer, key.row, key.col);
+#endif
+}
+
+/* translates Fn keycode to action */
+action_t keymap_fn_to_action(uint8_t keycode)
+{
+    return (action_t) {
+#ifndef KEYMAP_EX_ENABLE
+        .code = pgm_read_word(&fn_actions[FN_INDEX(keycode)])
+#else
+        .code = eeconfig_read_keymap_fn_action(FN_INDEX(keycode))
+#endif
+    };
+}
+
+#ifdef KEYMAP_EX_ENABLE
+const uint8_t* keymaps_pointer(void) {
+    return (const uint8_t*)keymaps;
+}
+
+const uint16_t* fn_actions_pointer(void) {
+    return fn_actions;
+}
+#endif
diff --git a/keyboard/ghpad/keymap_common.h b/keyboard/ghpad/keymap_common.h
new file mode 100644
index 00000000..32f4019f
--- /dev/null
+++ b/keyboard/ghpad/keymap_common.h
@@ -0,0 +1,54 @@
+/*
+Copyright 2012,2013 Jun Wako <wakojun@gmail.com>
+
+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://www.gnu.org/licenses/>.
+*/
+#ifndef KEYMAP_COMMON_H
+#define KEYMAP_COMMON_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/pgmspace.h>
+#include "keycode.h"
+#include "action.h"
+#include "action_macro.h"
+#include "report.h"
+#include "host.h"
+#include "print.h"
+#include "debug.h"
+#include "keymap.h"
+#include "keymap_ex.h"
+
+extern const uint8_t keymaps[][MATRIX_ROWS][MATRIX_COLS];
+extern const uint16_t fn_actions[];
+
+/* GHPad keymap definition macro
+ */
+#define KEYMAP( \
+    K0A, K0B, K0C, K0D, \
+    K1A, K1B, K1C, K1D, \
+    K2A, K2B, K2C, K2D, \
+    K3A, K3B, K3C, K3D, \
+    K4A, K4B, K4C, K4D, \
+    K5A, K5B, K5C, K5D  \
+) { \
+    { KC_##K0A, KC_##K0B, KC_##K0C, KC_##K0D }, \
+    { KC_##K1A, KC_##K1B, KC_##K1C, KC_##K1D }, \
+    { KC_##K2A, KC_##K2B, KC_##K2C, KC_##K2D }, \
+    { KC_##K3A, KC_##K3B, KC_##K3C, KC_##K3D }, \
+    { KC_##K4A, KC_##K4B, KC_##K4C, KC_##K4D }, \
+    { KC_##K5A, KC_##K5B, KC_##K5C, KC_##K5D }  \
+}
+
+#endif