diff --git a/hif/src/sdio/hif_sdio_dev.c b/hif/src/sdio/hif_sdio_dev.c
index 9a4e284313df..9dd9d82c43df 100644
--- a/hif/src/sdio/hif_sdio_dev.c
+++ b/hif/src/sdio/hif_sdio_dev.c
@@ -40,7 +40,6 @@
 #include "if_sdio.h"
 #include "regtable_sdio.h"
 
-
 /**
  * hif_dev_alloc_rx_buffer() - allocate rx buffer.
  * @pDev: sdio device context
@@ -293,6 +292,40 @@ QDF_STATUS hif_dev_dsr_handler(void *context)
 	return status;
 }
 
+/** hif_dev_set_mailbox_swap() - Set the mailbox swap from firmware
+ * @pdev : The HIF layer object
+ *
+ * Return: none
+ */
+void hif_dev_set_mailbox_swap(struct hif_sdio_dev *pdev)
+{
+	struct hif_sdio_device *hif_device = hif_dev_from_hif(pdev);
+
+	HIF_ENTER();
+
+	hif_device->swap_mailbox = true;
+
+	HIF_EXIT();
+}
+
+/** hif_dev_get_mailbox_swap() - Get the mailbox swap setting
+ * @pdev : The HIF layer object
+ *
+ * Return: none
+ */
+bool hif_dev_get_mailbox_swap(struct hif_sdio_dev *pdev)
+{
+	struct hif_sdio_device *hif_device;
+
+	HIF_ENTER();
+
+	hif_device = hif_dev_from_hif(pdev);
+
+	HIF_EXIT();
+
+	return hif_device->swap_mailbox;
+}
+
 /**
  * hif_dev_setup() - set up sdio device.
  * @pDev: sdio device context
diff --git a/hif/src/sdio/hif_sdio_dev.h b/hif/src/sdio/hif_sdio_dev.h
index a5560fc0909a..077f50ed4af0 100644
--- a/hif/src/sdio/hif_sdio_dev.h
+++ b/hif/src/sdio/hif_sdio_dev.h
@@ -64,5 +64,9 @@ QDF_STATUS hif_dev_get_mbox_address(struct hif_sdio_dev *pdev,
 				    uint32_t config_len);
 
 void hif_dev_get_mbox_block_size(void *config);
+
+void hif_dev_set_mailbox_swap(struct hif_sdio_dev *pdev);
+
+bool hif_dev_get_mailbox_swap(struct hif_sdio_dev *pdev);
 #endif
 #endif /* HIF_SDIO_DEV_H_ */
diff --git a/hif/src/sdio/hif_sdio_internal.h b/hif/src/sdio/hif_sdio_internal.h
index b185244a6c7f..67c8ebfab7f1 100644
--- a/hif/src/sdio/hif_sdio_internal.h
+++ b/hif/src/sdio/hif_sdio_internal.h
@@ -25,6 +25,14 @@
 #include "htc_api.h"
 #include "hif_internal.h"
 
+#if defined(CONFIG_SDIO_TRANSFER_MAILBOX)
+#include <transfer/mailbox.h>
+#elif defined(CONFIG_SDIO_TRANSFER_ADMA)
+#error "Error - Not implemented yet"
+#else
+#error "Error - Invalid transfer method"
+#endif
+
 #define INVALID_MAILBOX_NUMBER 0xFF
 
 #define HIF_SDIO_RX_BUFFER_SIZE            1792
@@ -37,51 +45,6 @@
 
 #define ATH_DEBUG_MAX_MASK 32
 
-#define OTHER_INTS_ENABLED (INT_STATUS_ENABLE_ERROR_MASK |   \
-			    INT_STATUS_ENABLE_CPU_MASK   |   \
-			    INT_STATUS_ENABLE_COUNTER_MASK)
-
-/* HTC operational parameters */
-#define HTC_TARGET_RESPONSE_TIMEOUT        2000 /* in ms */
-#define HTC_TARGET_DEBUG_INTR_MASK         0x01
-#define HTC_TARGET_CREDIT_INTR_MASK        0xF0
-
-#define MAILBOX_COUNT 4
-#define MAILBOX_FOR_BLOCK_SIZE 1
-#define MAILBOX_USED_COUNT 2
-#if defined(SDIO_3_0)
-#define MAILBOX_LOOKAHEAD_SIZE_IN_WORD 2
-#else
-#define MAILBOX_LOOKAHEAD_SIZE_IN_WORD 1
-#endif
-#define AR6K_TARGET_DEBUG_INTR_MASK     0x01
-
-PREPACK struct MBOX_IRQ_PROC_REGISTERS {
-	uint8_t host_int_status;
-	uint8_t cpu_int_status;
-	uint8_t error_int_status;
-	uint8_t counter_int_status;
-	uint8_t mbox_frame;
-	uint8_t rx_lookahead_valid;
-	uint8_t host_int_status2;
-	uint8_t gmbox_rx_avail;
-	uint32_t rx_lookahead[MAILBOX_LOOKAHEAD_SIZE_IN_WORD * MAILBOX_COUNT];
-	uint32_t int_status_enable;
-} POSTPACK;
-
-PREPACK struct MBOX_IRQ_ENABLE_REGISTERS {
-	uint8_t int_status_enable;
-	uint8_t cpu_int_status_enable;
-	uint8_t error_status_enable;
-	uint8_t counter_int_status_enable;
-} POSTPACK;
-
-#define TOTAL_CREDIT_COUNTER_CNT 4
-
-PREPACK struct MBOX_COUNTER_REGISTERS {
-	uint32_t counter[TOTAL_CREDIT_COUNTER_CNT];
-} POSTPACK;
-
 #define SDIO_NUM_DATA_RX_BUFFERS  64
 #define SDIO_DATA_RX_SIZE         1664
 
@@ -90,9 +53,6 @@ struct hif_sdio_device {
 	qdf_spinlock_t Lock;
 	qdf_spinlock_t TxLock;
 	qdf_spinlock_t RxLock;
-	struct MBOX_IRQ_PROC_REGISTERS IrqProcRegisters;
-	struct MBOX_IRQ_ENABLE_REGISTERS IrqEnableRegisters;
-	struct MBOX_COUNTER_REGISTERS MailBoxCounterRegisters;
 	struct hif_msg_callbacks hif_callbacks;
 	struct hif_device_mbox_info MailBoxInfo;
 	uint32_t BlockSize;
@@ -105,6 +65,8 @@ struct hif_sdio_device {
 	int RecheckIRQStatusCnt;
 	uint32_t RecvStateFlags;
 	void *pTarget;
+	bool swap_mailbox;
+	struct devRegisters devRegisters;
 };
 
 #define LOCK_HIF_DEV(device)    qdf_spin_lock(&(device)->Lock)
diff --git a/hif/src/sdio/if_sdio.c b/hif/src/sdio/if_sdio.c
index 5808d4175fa5..0fefb9cb8d0c 100644
--- a/hif/src/sdio/if_sdio.c
+++ b/hif/src/sdio/if_sdio.c
@@ -43,12 +43,12 @@
 #include "pld_sdio.h"
 #include "targaddrs.h"
 #include "sdio_api.h"
+#include <hif_sdio_dev.h>
 #ifndef REMOVE_PKT_LOG
 #include "ol_txrx_types.h"
 #include "pktlog_ac_api.h"
 #include "pktlog_ac.h"
 #endif
-
 #ifndef ATH_BUS_PM
 #ifdef CONFIG_PM
 #define ATH_BUS_PM
@@ -500,7 +500,7 @@ void hif_sdio_set_mailbox_swap(struct hif_softc *hif_sc)
 	struct hif_sdio_softc *scn = HIF_GET_SDIO_SOFTC(hif_sc);
 	struct hif_sdio_dev *hif_device = scn->hif_handle;
 
-	hif_device->swap_mailbox = true;
+	hif_dev_set_mailbox_swap(hif_device);
 }
 
 /**
diff --git a/hif/src/sdio/native_sdio/include/hif_internal.h b/hif/src/sdio/native_sdio/include/hif_internal.h
index a25c87a8070b..315808979d09 100644
--- a/hif/src/sdio/native_sdio/include/hif_internal.h
+++ b/hif/src/sdio/native_sdio/include/hif_internal.h
@@ -218,7 +218,6 @@ struct hif_sdio_dev {
 	const struct sdio_device_id *id;
 	struct mmc_host *host;
 	void *htc_context;
-	bool swap_mailbox;
 };
 
 struct HIF_DEVICE_OS_DEVICE_INFO {
diff --git a/hif/src/sdio/transfer/mailbox.c b/hif/src/sdio/transfer/mailbox.c
index 6d2af373bd3c..89ebdc10dd83 100644
--- a/hif/src/sdio/transfer/mailbox.c
+++ b/hif/src/sdio/transfer/mailbox.c
@@ -225,7 +225,7 @@ QDF_STATUS hif_dev_map_service_to_pipe(struct hif_sdio_dev *pdev, uint16_t svc,
 
 	switch (svc) {
 	case HTT_DATA_MSG_SVC:
-		if (pdev->swap_mailbox) {
+		if (hif_dev_get_mailbox_swap(pdev)) {
 			*ul_pipe = 1;
 			*dl_pipe = 0;
 		} else {
@@ -249,7 +249,7 @@ QDF_STATUS hif_dev_map_service_to_pipe(struct hif_sdio_dev *pdev, uint16_t svc,
 		break;
 
 	case WMI_CONTROL_SVC:
-		if (pdev->swap_mailbox) {
+		if (hif_dev_get_mailbox_swap(pdev)) {
 			*ul_pipe = 3;
 			*dl_pipe = 2;
 		} else {
@@ -279,16 +279,16 @@ void hif_dev_mask_interrupts(struct hif_sdio_device *pdev)
 	HIF_ENTER();
 	/* Disable all interrupts */
 	LOCK_HIF_DEV(pdev);
-	pdev->IrqEnableRegisters.int_status_enable = 0;
-	pdev->IrqEnableRegisters.cpu_int_status_enable = 0;
-	pdev->IrqEnableRegisters.error_status_enable = 0;
-	pdev->IrqEnableRegisters.counter_int_status_enable = 0;
+	mboxEnaRegs(pdev).int_status_enable = 0;
+	mboxEnaRegs(pdev).cpu_int_status_enable = 0;
+	mboxEnaRegs(pdev).error_status_enable = 0;
+	mboxEnaRegs(pdev).counter_int_status_enable = 0;
 	UNLOCK_HIF_DEV(pdev);
 
 	/* always synchronous */
 	status = hif_read_write(pdev->HIFDevice,
 				INT_STATUS_ENABLE_ADDRESS,
-				(char *)&pdev->IrqEnableRegisters,
+				(char *)&mboxEnaRegs(pdev),
 				sizeof(struct MBOX_IRQ_ENABLE_REGISTERS),
 				HIF_WR_SYNC_BYTE_INC, NULL);
 
@@ -310,13 +310,13 @@ void hif_dev_unmask_interrupts(struct hif_sdio_device *pdev)
 	/* Enable all the interrupts except for the internal
 	 * AR6000 CPU interrupt
 	 */
-	pdev->IrqEnableRegisters.int_status_enable =
+	mboxEnaRegs(pdev).int_status_enable =
 		INT_STATUS_ENABLE_ERROR_SET(0x01) |
 		INT_STATUS_ENABLE_CPU_SET(0x01)
 		| INT_STATUS_ENABLE_COUNTER_SET(0x01);
 
 	/* enable 2 mboxs INT */
-	pdev->IrqEnableRegisters.int_status_enable |=
+	mboxEnaRegs(pdev).int_status_enable |=
 		INT_STATUS_ENABLE_MBOX_DATA_SET(0x01) |
 		INT_STATUS_ENABLE_MBOX_DATA_SET(0x02);
 
@@ -325,17 +325,17 @@ void hif_dev_unmask_interrupts(struct hif_sdio_device *pdev)
 	 * #0 is used for report assertion from target
 	 * #1 is used for inform host that credit arrived
 	 */
-	pdev->IrqEnableRegisters.cpu_int_status_enable = 0x03;
+	mboxEnaRegs(pdev).cpu_int_status_enable = 0x03;
 
 	/* Set up the Error Interrupt Status Register */
-	pdev->IrqEnableRegisters.error_status_enable =
+	mboxEnaRegs(pdev).error_status_enable =
 		(ERROR_STATUS_ENABLE_RX_UNDERFLOW_SET(0x01)
 		 | ERROR_STATUS_ENABLE_TX_OVERFLOW_SET(0x01)) >> 16;
 
 	/* Set up the Counter Interrupt Status Register
 	 * (only for debug interrupt to catch fatal errors)
 	 */
-	pdev->IrqEnableRegisters.counter_int_status_enable =
+	mboxEnaRegs(pdev).counter_int_status_enable =
 	(COUNTER_INT_STATUS_ENABLE_BIT_SET(AR6K_TARGET_DEBUG_INTR_MASK)) >> 24;
 
 	UNLOCK_HIF_DEV(pdev);
@@ -343,7 +343,7 @@ void hif_dev_unmask_interrupts(struct hif_sdio_device *pdev)
 	/* always synchronous */
 	status = hif_read_write(pdev->HIFDevice,
 				INT_STATUS_ENABLE_ADDRESS,
-				(char *)&pdev->IrqEnableRegisters,
+				(char *)&mboxEnaRegs(pdev),
 				sizeof(struct MBOX_IRQ_ENABLE_REGISTERS),
 				HIF_WR_SYNC_BYTE_INC,
 				NULL);
@@ -895,13 +895,13 @@ static QDF_STATUS hif_dev_service_cpu_interrupt(struct hif_sdio_device *pdev)
 	uint8_t reg_buffer[4];
 	uint8_t cpu_int_status;
 
-	cpu_int_status = pdev->IrqProcRegisters.cpu_int_status &
-			 pdev->IrqEnableRegisters.cpu_int_status_enable;
+	cpu_int_status = mboxProcRegs(pdev).cpu_int_status &
+			 mboxEnaRegs(pdev).cpu_int_status_enable;
 
 	HIF_ERROR("%s: 0x%x", __func__, (uint32_t)cpu_int_status);
 
 	/* Clear the interrupt */
-	pdev->IrqProcRegisters.cpu_int_status &= ~cpu_int_status;
+	mboxProcRegs(pdev).cpu_int_status &= ~cpu_int_status;
 
 	/*set up the register transfer buffer to hit the register
 	 * 4 times , this is done to make the access 4-byte aligned
@@ -954,7 +954,7 @@ static QDF_STATUS hif_dev_service_error_interrupt(struct hif_sdio_device *pdev)
 	uint8_t reg_buffer[4];
 	uint8_t error_int_status = 0;
 
-	error_int_status = pdev->IrqProcRegisters.error_int_status & 0x0F;
+	error_int_status = mboxProcRegs(pdev).error_int_status & 0x0F;
 	HIF_ERROR("%s: 0x%x", __func__, error_int_status);
 
 	if (ERROR_INT_STATUS_WAKEUP_GET(error_int_status))
@@ -967,7 +967,7 @@ static QDF_STATUS hif_dev_service_error_interrupt(struct hif_sdio_device *pdev)
 		HIF_ERROR("%s: Error : Tx Overflow", __func__);
 
 	/* Clear the interrupt */
-	pdev->IrqProcRegisters.error_int_status &= ~error_int_status;
+	mboxProcRegs(pdev).error_int_status &= ~error_int_status;
 
 	/* set up the register transfer buffer to hit the register
 	 * 4 times , this is done to make the access 4-byte
@@ -1033,8 +1033,8 @@ QDF_STATUS hif_dev_service_counter_interrupt(struct hif_sdio_device *pdev)
 
 	AR_DEBUG_PRINTF(ATH_DEBUG_IRQ, ("Counter Interrupt\n"));
 
-	counter_int_status = pdev->IrqProcRegisters.counter_int_status &
-			     pdev->IrqEnableRegisters.counter_int_status_enable;
+	counter_int_status = mboxProcRegs(pdev).counter_int_status &
+			     mboxEnaRegs(pdev).counter_int_status_enable;
 
 	AR_DEBUG_PRINTF(ATH_DEBUG_IRQ,
 			("Valid interrupt source in COUNTER_INT_STATUS: 0x%x\n",
@@ -1051,6 +1051,8 @@ QDF_STATUS hif_dev_service_counter_interrupt(struct hif_sdio_device *pdev)
 	return QDF_STATUS_SUCCESS;
 }
 
+#define RX_LOOAHEAD_GET(pdev, i) \
+	mboxProcRegs(pdev).rx_lookahead[MAILBOX_LOOKAHEAD_SIZE_IN_WORD * i]
 /**
  * hif_dev_process_pending_irqs() - process pending interrupts
  * @pDev: hif sdio device context
@@ -1065,10 +1067,10 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 {
 	QDF_STATUS status = QDF_STATUS_SUCCESS;
 	uint8_t host_int_status = 0;
-	uint32_t look_ahead[MAILBOX_USED_COUNT];
+	uint32_t l_ahead[MAILBOX_USED_COUNT];
 	int i;
 
-	qdf_mem_zero(&look_ahead, sizeof(look_ahead));
+	qdf_mem_zero(&l_ahead, sizeof(l_ahead));
 	AR_DEBUG_PRINTF(ATH_DEBUG_IRQ,
 			("+ProcessPendingIRQs: (dev: 0x%lX)\n",
 			 (unsigned long)pdev));
@@ -1080,7 +1082,7 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 	 * This is a fully schedulable context.
 	 */
 	do {
-		if (pdev->IrqEnableRegisters.int_status_enable == 0) {
+		if (mboxEnaRegs(pdev).int_status_enable == 0) {
 			/* interrupt enables have been cleared, do not try
 			 * to process any pending interrupts that
 			 * may result in more bus transactions.
@@ -1090,8 +1092,8 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 		}
 		status = hif_read_write(pdev->HIFDevice,
 					HOST_INT_STATUS_ADDRESS,
-					(uint8_t *)&pdev->IrqProcRegisters,
-					sizeof(pdev->IrqProcRegisters),
+					(uint8_t *)&mboxProcRegs(pdev),
+					sizeof(mboxProcRegs(pdev)),
 					HIF_RD_SYNC_BYTE_INC, NULL);
 
 		if (QDF_IS_STATUS_ERROR(status))
@@ -1099,37 +1101,33 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 
 		if (AR_DEBUG_LVL_CHECK(ATH_DEBUG_IRQ)) {
 			hif_dev_dump_registers(pdev,
-					       &pdev->IrqProcRegisters,
-					       &pdev->IrqEnableRegisters,
-					       &pdev->MailBoxCounterRegisters);
+					       &mboxProcRegs(pdev),
+					       &mboxEnaRegs(pdev),
+					       &mboxCountRegs(pdev));
 		}
 
 		/* Update only those registers that are enabled */
-		host_int_status = pdev->IrqProcRegisters.host_int_status
-				  & pdev->IrqEnableRegisters.int_status_enable;
+		host_int_status = mboxProcRegs(pdev).host_int_status
+				  & mboxEnaRegs(pdev).int_status_enable;
 
 		/* only look at mailbox status if the HIF layer did not
 		 * provide this function, on some HIF interfaces reading
 		 * the RX lookahead is not valid to do
 		 */
 		for (i = 0; i < MAILBOX_USED_COUNT; i++) {
-			look_ahead[i] = 0;
+			l_ahead[i] = 0;
 			if (host_int_status & (1 << i)) {
 				/* mask out pending mailbox value, we use
 				 * "lookAhead" as the real flag for
 				 * mailbox processing below
 				 */
 				host_int_status &= ~(1 << i);
-				if (pdev->IrqProcRegisters.
+				if (mboxProcRegs(pdev).
 				    rx_lookahead_valid & (1 << i)) {
 					/* mailbox has a message and the
 					 * look ahead is valid
 					 */
-					look_ahead[i] =
-						pdev->
-						IrqProcRegisters.rx_lookahead[
-						MAILBOX_LOOKAHEAD_SIZE_IN_WORD *
-						i];
+					l_ahead[i] = RX_LOOAHEAD_GET(pdev, i);
 				}
 			}
 		} /*end of for loop */
@@ -1142,7 +1140,7 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 			break;
 
 		for (i = 0; i < MAILBOX_USED_COUNT; i++) {
-			if (look_ahead[i] != 0) {
+			if (l_ahead[i] != 0) {
 				bLookAheadValid = true;
 				break;
 			}
@@ -1160,11 +1158,11 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 			for (i = 0; i < MAILBOX_USED_COUNT; i++) {
 				int fetched = 0;
 
-				if (look_ahead[i] == 0)
+				if (l_ahead[i] == 0)
 					continue;
 				AR_DEBUG_PRINTF(ATH_DEBUG_IRQ,
 						("mbox[%d],lookahead:0x%X\n",
-						i, look_ahead[i]));
+						i, l_ahead[i]));
 				/* Mailbox Interrupt, the HTC layer may issue
 				 * async requests to empty the mailbox...
 				 * When emptying the recv mailbox we use the
@@ -1176,7 +1174,7 @@ QDF_STATUS hif_dev_process_pending_irqs(struct hif_sdio_device *pdev,
 				 */
 				status = hif_dev_recv_message_pending_handler(
 							pdev, i,
-							&look_ahead
+							&l_ahead
 							[i], 1,
 							async_processing,
 							&fetched);
diff --git a/hif/src/sdio/transfer/mailbox.h b/hif/src/sdio/transfer/mailbox.h
index 2228b120bdcd..0771ec1d6bfb 100644
--- a/hif/src/sdio/transfer/mailbox.h
+++ b/hif/src/sdio/transfer/mailbox.h
@@ -88,5 +88,4 @@ struct devRegisters {
 #define DEV_REGISTERS_SIZE	(sizeof(struct MBOX_IRQ_PROC_REGISTERS) + \
 				 sizeof(struct MBOX_IRQ_ENABLE_REGISTERS) + \
 				 sizeof(struct MBOX_COUNTER_REGISTERS))
-
 #endif /* _MAILBOX_H_ */
diff --git a/hif/src/sdio/transfer/transfer.c b/hif/src/sdio/transfer/transfer.c
index 622173335189..2587b8b34e2d 100644
--- a/hif/src/sdio/transfer/transfer.c
+++ b/hif/src/sdio/transfer/transfer.c
@@ -90,7 +90,7 @@ QDF_STATUS hif_dev_send_buffer(struct hif_sdio_device *pdev, uint32_t xfer_id,
 	QDF_STATUS status;
 	unsigned char *pData;
 	struct hif_sendContext *sctx;
-	uint32_t request = HIF_WR_ASYNC_BLOCK_INC;
+	uint32_t request = hif_get_send_buffer_flags(pdev);
 	uint32_t padded_length, addr = 0;
 	int frag_count = 0, i, count, head_len;
 
diff --git a/hif/src/sdio/transfer/transfer.h b/hif/src/sdio/transfer/transfer.h
index cbeb19a4f941..6dc6bd4e2df0 100644
--- a/hif/src/sdio/transfer/transfer.h
+++ b/hif/src/sdio/transfer/transfer.h
@@ -41,6 +41,12 @@
 #include <a_debug.h>
 #include "hif_sdio_internal.h"
 
+#if defined(CONFIG_SDIO_TRANSFER_MAILBOX) && defined(CONFIG_SDIO_TRANSFER_ADMA)
+#error "-----------------------------------------------"
+#error "Error - Both transfer methods cannot be enabled"
+#error "-----------------------------------------------"
+#endif
+
 #define NBUF_ALLOC_FAIL_WAIT_TIME 100
 /* high nibble */
 #define BUNDLE_COUNT_HIGH(f) (((f) & 0x0C) << 2)
@@ -84,4 +90,18 @@ QDF_STATUS hif_dev_process_recv_header(struct hif_sdio_device *pdev,
 				       HTC_PACKET *packet,
 				       uint32_t *next_look_aheads,
 				       int *num_look_aheads);
+#ifdef CONFIG_SDIO_TRANSFER_MAILBOX
+static inline uint32_t hif_get_send_buffer_flags(struct hif_sdio_device *pdev)
+{
+	if (pdev)
+		return (uint32_t)HIF_WR_ASYNC_BLOCK_INC;
+
+	HIF_ERROR("%s: hif obj is null. Not populating xfer flags", __func__);
+
+	return 0;
+}
+#elif defined(CONFIG_SDIO_TRANSFER_ADMA)
+#error "Error - Not implemented yet"
+#endif
+
 #endif /* __TRANSFER_H__ */