diff --git a/hal/explicit_pinmap.c b/hal/explicit_pinmap.c
new file mode 100644
index 0000000000..d341de2efa
--- /dev/null
+++ b/hal/explicit_pinmap.c
@@ -0,0 +1,83 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2019 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed_error.h"
+#include "spi_api.h"
+#include "pwmout_api.h"
+#include "analogin_api.h"
+#include "analogout_api.h"
+#include "i2c_api.h"
+#include "serial_api.h"
+
+
+/*
+ * This file provides default definitions of xxx_direct() functions for peripherals.
+ * in all cases standard init function is called, which won't give any ROM memory savings.
+ *
+ */
+
+#if DEVICE_SPI
+MBED_WEAK void spi_init_direct(spi_t *obj, const spi_pinmap_t *pinmap)
+{
+    spi_init(obj, pinmap->mosi_pin, pinmap->miso_pin, pinmap->sclk_pin, pinmap->ssel_pin);
+}
+#endif
+
+#if DEVICE_PWMOUT
+MBED_WEAK void pwmout_init_direct(pwmout_t *obj, const PinMap *pinmap)
+{
+    pwmout_init(obj, pinmap->pin);
+}
+#endif
+
+#if DEVICE_ANALOGIN
+MBED_WEAK void analogin_init_direct(analogin_t *obj, const PinMap *pinmap)
+{
+    printf("Pin: %d \r\n", pinmap->pin);
+    //wait_ns(5000);
+
+    analogin_init(obj, pinmap->pin);
+}
+#endif
+
+#if DEVICE_ANALOGOUT
+MBED_WEAK void analogout_init_direct(dac_t *obj, const PinMap *pinmap)
+{
+    analogout_init(obj, pinmap->pin);
+}
+#endif
+
+#if DEVICE_I2C
+MBED_WEAK void i2c_init_direct(i2c_t *obj, const i2c_pinmap_t *pinmap)
+{
+    i2c_init(obj, pinmap->sda_pin, pinmap->scl_pin);
+}
+#endif
+
+#if DEVICE_SERIAL
+MBED_WEAK void serial_init_direct(serial_t *obj, const serial_pinmap_t *pinmap)
+{
+    serial_init(obj, pinmap->tx_pin, pinmap->rx_pin);
+}
+
+#if DEVICE_SERIAL_FC
+MBED_WEAK void serial_set_flow_control_direct(serial_t *obj, FlowControl type, const serial_fc_pinmap_t *pinmap)
+{
+    serial_set_flow_control(obj, type, pinmap->rx_flow_pin, pinmap->tx_flow_pin);
+}
+#endif
+#endif