diff --git a/embed/embed.mk b/embed/embed.mk
new file mode 100644
index 0000000000000..edcb9a5c23ff5
--- /dev/null
+++ b/embed/embed.mk
@@ -0,0 +1,31 @@
+# where embed object files go (they have a name prefix to prevent filename clashes)
+EMBED_BUILD = $(BUILD)/embed
+
+# embed object files
+EMBED_O_BASENAME = \
+	hal_gpio.o \
+
+# prepend the build destination prefix to the embed object files
+EMBED_O = $(addprefix $(EMBED_BUILD)/, $(EMBED_O_BASENAME))
+
+# Relative to the top of the mbed tree
+
+MBED_TOP     = $(TOP)/../mbed/libraries/mbed
+MBED_API     = $(MBED_TOP)/api
+MBED_COMMON  = $(MBED_TOP)/common
+MBED_HAL_INC = $(MBED_TOP)/hal
+MBED_HAL_SRC = $(MBED_TOP)/targets/hal/TARGET_STM/TARGET_STM32F4XX
+
+CFLAGS_EMBED = -I$(TOP)/embed -I$(MBED_API) -I$(MBED_HAL_INC) -I$(MBED_HAL_SRC)
+
+vpath %.c $(MBED_HAL_SRC)
+SRC_HAL = \
+	pinmap.c \
+	analogin_api.c \
+	gpio_api.c \
+
+vpath %.c $(MBED_COMMON)
+SRC_HAL += \
+	pinmap_common.c \
+	exit.c \
+
diff --git a/embed/hal.h b/embed/hal.h
new file mode 100644
index 0000000000000..33c7b99a57dfa
--- /dev/null
+++ b/embed/hal.h
@@ -0,0 +1,7 @@
+typedef struct {
+  const char *const_name;
+  machine_int_t const_val;
+} hal_int_const;
+
+void hal_target_init_Gpio_class(mp_obj_t gpio_class_type);
+
diff --git a/embed/hal_gpio.c b/embed/hal_gpio.c
new file mode 100644
index 0000000000000..59422d0d385ff
--- /dev/null
+++ b/embed/hal_gpio.c
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "runtime.h"
+#include "map.h"
+
+#include "gpio_api.h"
+#include "hal.h"
+#include "hal_gpio.h"
+
+static mp_obj_t gpio_obj_mode(mp_obj_t self_in, mp_obj_t mode_obj) {
+    hal_gpio_obj_t *self = self_in;
+    int mode = mp_obj_get_int(mode_obj);
+    gpio_mode(&self->gpio, mode);
+    return mp_const_none;
+}
+
+static mp_obj_t gpio_obj_dir(mp_obj_t self_in, mp_obj_t dir_obj) {
+    hal_gpio_obj_t *self = self_in;
+    int dir = mp_obj_get_int(dir_obj);
+    gpio_dir(&self->gpio, dir);
+    return mp_const_none;
+}
+
+static mp_obj_t gpio_obj_read(mp_obj_t self_in) {
+    hal_gpio_obj_t *self = self_in;
+    return MP_OBJ_NEW_SMALL_INT(gpio_read(&self->gpio));
+}
+
+static mp_obj_t gpio_obj_write(mp_obj_t self_in, mp_obj_t value_obj) {
+    hal_gpio_obj_t *self = self_in;
+    int value = mp_obj_get_int(value_obj);
+    gpio_dir(&self->gpio, value);
+    return mp_const_none;
+}
+
+static void gpio_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
+    hal_gpio_obj_t *self = self_in;
+    print(env, "<GPIO %u>", self->pin);
+}
+
+static MP_DEFINE_CONST_FUN_OBJ_2(gpio_obj_mode_obj,  gpio_obj_mode);
+static MP_DEFINE_CONST_FUN_OBJ_2(gpio_obj_dir_obj,   gpio_obj_dir);
+static MP_DEFINE_CONST_FUN_OBJ_1(gpio_obj_read_obj,  gpio_obj_read);
+static MP_DEFINE_CONST_FUN_OBJ_2(gpio_obj_write_obj, gpio_obj_write);
+
+static bool gpio_call_kwarg(mp_obj_t param, mp_obj_t key, mp_obj_t value) {
+    hal_gpio_obj_t *self = param;
+    mp_obj_t fn = rt_load_attr(self, mp_obj_str_get_qstr(key));
+    if (fn != MP_OBJ_NULL) {
+        rt_call_function_1(fn, value);
+    }
+    return true;
+}
+
+mp_obj_t hal_Gpio_init(uint n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+    hal_gpio_obj_t *self = args[0];
+    int pin = mp_obj_get_int(args[1]);
+    gpio_init(&self->gpio, pin, PIN_INPUT);
+    mp_map_walk(kwargs, gpio_call_kwarg, self);
+    return mp_const_none;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN_KW(hal_Gpio_init_obj, 2, 2, hal_Gpio_init);
+
+void hal_init_Gpio_class(mp_obj_t module_obj) {
+    mp_obj_t gpio_class_type = mp_obj_new_type("Gpio", mp_const_empty_tuple, mp_obj_new_dict(0));
+    ((mp_obj_type_t *)gpio_class_type)->print = gpio_obj_print;
+    rt_store_attr(gpio_class_type, QSTR_FROM_STR_STATIC("__init__"), (mp_obj_t)&hal_Gpio_init_obj);
+    rt_store_attr(gpio_class_type, QSTR_FROM_STR_STATIC("dir"), (mp_obj_t)&gpio_obj_dir_obj);
+    rt_store_attr(gpio_class_type, QSTR_FROM_STR_STATIC("mode"), (mp_obj_t)&gpio_obj_mode_obj);
+    rt_store_attr(gpio_class_type, QSTR_FROM_STR_STATIC("read"), (mp_obj_t)&gpio_obj_read_obj);
+    rt_store_attr(gpio_class_type, QSTR_FROM_STR_STATIC("write"), (mp_obj_t)&gpio_obj_write_obj);
+    rt_store_attr(module_obj, QSTR_FROM_STR_STATIC("Gpio"), gpio_class_type);
+
+    // Allow the target to add its own constants and methods
+    hal_target_init_Gpio_class(gpio_class_type);
+}
diff --git a/embed/hal_gpio.h b/embed/hal_gpio.h
new file mode 100644
index 0000000000000..d68ed40945081
--- /dev/null
+++ b/embed/hal_gpio.h
@@ -0,0 +1,8 @@
+typedef struct {
+    mp_obj_base_t base;
+    PinName pin;
+    gpio_t gpio;
+} hal_gpio_obj_t;
+
+void hal_init_Gpio_class(mp_obj_t module_obj);
+
diff --git a/py/map.c b/py/map.c
index 2bae8b28d74bb..44ec84752ed27 100644
--- a/py/map.c
+++ b/py/map.c
@@ -135,6 +135,21 @@ mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
     }
 }
 
+void mp_map_walk(mp_map_t *map, bool (*fn)(void *param, mp_obj_t key, mp_obj_t value), void *param) {
+    uint pos;
+    if (!map) {
+        return;
+    }
+    for (pos = 0; pos < map->alloc; pos++) {
+        mp_map_elem_t *elem = &map->table[pos];
+        if (elem->key != NULL) {
+            if (!fn(param, elem->key, elem->value)) {
+                return;
+            }
+        }
+    }
+}
+
 /******************************************************************************/
 /* set                                                                        */
 
diff --git a/py/map.h b/py/map.h
index 7acb5a98a7469..294876e9d8a5e 100644
--- a/py/map.h
+++ b/py/map.h
@@ -31,6 +31,7 @@ mp_map_t *mp_map_new(int n);
 void mp_map_deinit(mp_map_t *map);
 void mp_map_free(mp_map_t *map);
 mp_map_elem_t* mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t lookup_kind);
+void mp_map_walk(mp_map_t *map, bool (*fn)(mp_obj_t param, mp_obj_t key, mp_obj_t value), mp_obj_t param);
 void mp_map_clear(mp_map_t *map);
 
 void mp_set_init(mp_set_t *set, int n);
diff --git a/py/obj.h b/py/obj.h
index 9c6a354220861..2025fba7fed22 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -61,6 +61,7 @@ typedef struct _mp_obj_base_t mp_obj_base_t;
 #define MP_DEFINE_CONST_FUN_OBJ_3(obj_name, fun_name) MP_DEFINE_CONST_FUN_OBJ_VOID_PTR(obj_name, false, 3, 3, (mp_fun_3_t)fun_name)
 #define MP_DEFINE_CONST_FUN_OBJ_VAR(obj_name, n_args_min, fun_name) MP_DEFINE_CONST_FUN_OBJ_VOID_PTR(obj_name, false, n_args_min, (~((machine_uint_t)0)), (mp_fun_var_t)fun_name)
 #define MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(obj_name, n_args_min, n_args_max, fun_name) MP_DEFINE_CONST_FUN_OBJ_VOID_PTR(obj_name, false, n_args_min, n_args_max, (mp_fun_var_t)fun_name)
+#define MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN_KW(obj_name, n_args_min, n_args_max, fun_name) MP_DEFINE_CONST_FUN_OBJ_VOID_PTR(obj_name, true, n_args_min, n_args_max, (mp_fun_var_t)fun_name)
 #define MP_DEFINE_CONST_FUN_OBJ_KW(obj_name, n_args_min, fun_name) MP_DEFINE_CONST_FUN_OBJ_VOID_PTR(obj_name, true, n_args_min, (~((machine_uint_t)0)), (mp_fun_kw_t)fun_name)
 
 // These macros are used to declare and define constant staticmethond and classmethod objects
diff --git a/stm/Makefile b/stm/Makefile
index 12fd0d9662a7e..6dc6bf61d7c65 100644
--- a/stm/Makefile
+++ b/stm/Makefile
@@ -5,6 +5,7 @@ QSTR_DEFS = qstrdefsport.h
 
 # include py core make definitions
 include ../py/py.mk
+include ../embed/embed.mk
 
 CMSIS_DIR=cmsis
 STMPERIPH_DIR=stmperiph
@@ -23,6 +24,7 @@ CFLAGS += -I$(STMUSBD_DIR)
 CFLAGS += -I$(STMUSBH_DIR)
 CFLAGS += -I$(FATFS_DIR)
 #CFLAGS += -I$(CC3K_DIR)
+CFLAGS += $(CFLAGS_EMBED)
 
 #Debugging/Optimization
 ifeq ($(DEBUG), 1)
@@ -63,6 +65,7 @@ SRC_C = \
 	adc.c \
 	rtc.c \
 	file.c \
+	hal_target_gpio.c \
 #	pybwlan.c \
 
 SRC_S = \
@@ -145,11 +148,16 @@ SRC_CC3K = $(addprefix $(CC3K_DIR)/,\
 	pybcc3k.c \
 	)
 
-OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o) $(SRC_S:.s=.o) $(SRC_STMPERIPH:.c=.o) $(SRC_STMUSB:.c=.o))
+OBJ = $(PY_O) $(EMBED_O)
+OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o) $(SRC_S:.s=.o) $(SRC_STMPERIPH:.c=.o) $(SRC_STMUSB:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_STMUSBD:.c=.o))
 #OBJ += $(addprefix $(BUILD)/, $(SRC_STMUSBH:.c=.o))
 OBJ += $(addprefix $(BUILD)/, $(SRC_FATFS:.c=.o))
 #OBJ += $(addprefix $(BUILD)/, $(SRC_CC3K:.c=.o))
+OBJ += $(addprefix $(BUILD)/hal/, $(SRC_HAL:.c=.o))
+
+$(BUILD)/hal/%.o: %.c
+	$(compile_c)
 
 all: $(BUILD) $(BUILD)/flash.dfu
 
diff --git a/stm/cmsis/cmsis.h b/stm/cmsis/cmsis.h
new file mode 100644
index 0000000000000..863efb3794f01
--- /dev/null
+++ b/stm/cmsis/cmsis.h
@@ -0,0 +1,14 @@
+/* mbed Microcontroller Library - CMSIS
+ * Copyright (C) 2009-2011 ARM Limited. All rights reserved.
+ * 
+ * A generic CMSIS include header, pulling in STM32F407 specifics
+ */
+
+#ifndef MBED_CMSIS_H
+#define MBED_CMSIS_H
+
+#include "stm32f4xx.h"
+#include "cmsis_nvic.h"
+
+#endif
+
diff --git a/stm/cmsis/cmsis_nvic.h b/stm/cmsis/cmsis_nvic.h
new file mode 100644
index 0000000000000..c259328d4ed04
--- /dev/null
+++ b/stm/cmsis/cmsis_nvic.h
@@ -0,0 +1,26 @@
+/* mbed Microcontroller Library - cmsis_nvic
+ * Copyright (c) 2009-2011 ARM Limited. All rights reserved.
+ *
+ * CMSIS-style functionality to support dynamic vectors
+ */
+
+#ifndef MBED_CMSIS_NVIC_H
+#define MBED_CMSIS_NVIC_H
+
+#define NVIC_NUM_VECTORS      (16 + 81)   // CORE + MCU Peripherals
+#define NVIC_USER_IRQ_OFFSET  16
+
+#include "cmsis.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void NVIC_SetVector(IRQn_Type IRQn, uint32_t vector);
+uint32_t NVIC_GetVector(IRQn_Type IRQn);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/stm/hal_target_gpio.c b/stm/hal_target_gpio.c
new file mode 100644
index 0000000000000..ee18d6f0512e3
--- /dev/null
+++ b/stm/hal_target_gpio.c
@@ -0,0 +1,50 @@
+#include <string.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "runtime.h"
+
+#include "gpio_api.h"
+#include "hal.h"
+#include "hal_gpio.h"
+
+const static hal_int_const target_gpio_const[] = {
+  { "DIR_INPUT",        0 },
+  { "DIR_OUTPUT",       1 },
+
+  { "PUD_NONE",         0 },
+  { "PUD_UP",           1 },
+  { "PUD_DOWN",         2 },
+  { "PUD_OPEN_DRAIN",   3 },
+
+  { "SPEED_LOW",        0 },
+  { "SPEED_MEDIUM",     1 },
+  { "SPEED_FAST",       2 },
+  { "SPEED_HIGH",       3 },
+
+  { NULL, 0 }
+};
+
+static mp_obj_t gpio_obj_speed(mp_obj_t self_in, mp_obj_t speed_obj) {
+    hal_gpio_obj_t *self = self_in;
+    int speed = mp_obj_get_int(speed_obj) & 3;
+
+    uint32_t port_index = (uint32_t) self->pin >> 4;
+    GPIO_TypeDef *port_reg = (GPIO_TypeDef *) (GPIOA_BASE + (port_index << 10));
+
+    int pin_shift = (self->pin & 0x0f) << 1;
+    port_reg->OSPEEDR = (port_reg->OSPEEDR & ~(3 << pin_shift)) | (speed << pin_shift);
+
+    return mp_const_none;
+}
+
+static MP_DEFINE_CONST_FUN_OBJ_2(gpio_obj_speed_obj,  gpio_obj_speed);
+
+void hal_target_init_Gpio_class(mp_obj_t gpio_class_type) {
+    for (const hal_int_const *c = target_gpio_const; c->const_name != NULL; c++) {
+        rt_store_attr(gpio_class_type, qstr_from_str(c->const_name), MP_OBJ_NEW_SMALL_INT(c->const_val));
+    }
+    rt_store_attr(gpio_class_type, QSTR_FROM_STR_STATIC("speed"), (mp_obj_t)&gpio_obj_speed_obj);
+}
diff --git a/stm/main.c b/stm/main.c
index 90fdab3d22375..2ae607ee35b2a 100644
--- a/stm/main.c
+++ b/stm/main.c
@@ -45,6 +45,9 @@
 #include "adc.h"
 #include "rtc.h"
 #include "file.h"
+#include "gpio_api.h"
+#include "hal.h"
+#include "hal_gpio.h"
 
 int errno;
 
@@ -72,6 +75,11 @@ void __fatal_error(const char *msg) {
     }
 }
 
+// mbed_die is provided for the mbed hal routines
+void mbed_die(void) {
+    __fatal_error("mbed_die");
+}
+
 static mp_obj_t pyb_config_source_dir = MP_OBJ_NULL;
 static mp_obj_t pyb_config_main = MP_OBJ_NULL;
 
@@ -319,7 +327,7 @@ int readline(vstr_t *line, const char *prompt) {
                 return 1;
             } else if (c == 27) {
                 escape = true;
-            } else if (c == 127) {
+            } else if (c == 127 || c == 8) {
                 if (vstr_len(line) > len) {
                     vstr_cut_tail(line, 1);
                     stdout_tx_str("\b \b");
@@ -670,6 +678,7 @@ int main(void) {
         rt_store_attr(m, MP_QSTR_Usart, rt_make_function_n(2, pyb_Usart));
         rt_store_attr(m, qstr_from_str("ADC_all"), (mp_obj_t)&pyb_ADC_all_obj);
         rt_store_attr(m, MP_QSTR_ADC, (mp_obj_t)&pyb_ADC_obj);
+        hal_target_init_Gpio_class(m);
         rt_store_name(MP_QSTR_pyb, m);
 
         rt_store_name(MP_QSTR_open, rt_make_function_n(2, pyb_io_open));
diff --git a/stm/qstrdefsport.h b/stm/qstrdefsport.h
index 4fbcb1e5a4e42..7c4af293515d4 100644
--- a/stm/qstrdefsport.h
+++ b/stm/qstrdefsport.h
@@ -23,7 +23,9 @@ Q(rand)
 Q(Led)
 Q(Servo)
 Q(I2C)
+Q(Gpio)
 Q(gpio)
 Q(Usart)
 Q(ADC)
+Q(Adc)
 Q(open)