Diff: arch/TARGET_NXP/lpc17_emac.c

Revision:

33:9de8bd8ca1c8

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/arch/TARGET_NXP/lpc17_emac.c	Thu May 26 09:00:26 2016 +0100
@@ -0,0 +1,1046 @@
+/**********************************************************************
+* $Id$		lpc17_emac.c			2011-11-20
+*//**
+* @file		lpc17_emac.c
+* @brief	LPC17 ethernet driver for LWIP
+* @version	1.0
+* @date		20. Nov. 2011
+* @author	NXP MCU SW Application Team
+*
+* Copyright(C) 2011, NXP Semiconductor
+* All rights reserved.
+*
+***********************************************************************
+* Software that is described herein is for illustrative purposes only
+* which provides customers with programming information regarding the
+* products. This software is supplied "AS IS" without any warranties.
+* NXP Semiconductors assumes no responsibility or liability for the
+* use of the software, conveys no license or title under any patent,
+* copyright, or mask work right to the product. NXP Semiconductors
+* reserves the right to make changes in the software without
+* notification. NXP Semiconductors also make no representation or
+* warranty that such application will be suitable for the specified
+* use without further testing or modification.
+**********************************************************************/
+
+#include "lwip/opt.h"
+#include "lwip/sys.h"
+#include "lwip/def.h"
+#include "lwip/mem.h"
+#include "lwip/pbuf.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "netif/etharp.h"
+#include "netif/ppp_oe.h"
+
+#include "lpc17xx_emac.h"
+#include "eth_arch.h"
+#include "lpc_emac_config.h"
+#include "lpc_phy.h"
+#include "sys_arch.h"
+
+#include "mbed_interface.h"
+#include <string.h>
+
+#ifndef LPC_EMAC_RMII
+#error LPC_EMAC_RMII is not defined!
+#endif
+
+#if LPC_NUM_BUFF_TXDESCS < 2
+#error LPC_NUM_BUFF_TXDESCS must be at least 2
+#endif
+
+#if LPC_NUM_BUFF_RXDESCS < 3
+#error LPC_NUM_BUFF_RXDESCS must be at least 3
+#endif
+
+/** @defgroup lwip17xx_emac_DRIVER	lpc17 EMAC driver for LWIP
+ * @ingroup lwip_emac
+ *
+ * @{
+ */
+
+#if NO_SYS == 0
+/** \brief  Driver transmit and receive thread priorities
+ *
+ * Thread priorities for receive thread and TX cleanup thread. Alter
+ * to prioritize receive or transmit bandwidth. In a heavily loaded
+ * system or with LEIP_DEBUG enabled, the priorities might be better
+ * the same. */
+#define RX_PRIORITY   (osPriorityNormal)
+#define TX_PRIORITY   (osPriorityNormal)
+
+/** \brief  Debug output formatter lock define
+ *
+ * When using FreeRTOS and with LWIP_DEBUG enabled, enabling this
+ * define will allow RX debug messages to not interleave with the
+ * TX messages (so they are actually readable). Not enabling this
+ * define when the system is under load will cause the output to
+ * be unreadable. There is a small tradeoff in performance for this
+ * so use it only for debug. */
+//#define LOCK_RX_THREAD
+
+/** \brief  Receive group interrupts
+ */
+#define RXINTGROUP (EMAC_INT_RX_OVERRUN | EMAC_INT_RX_ERR | EMAC_INT_RX_DONE)
+
+/** \brief  Transmit group interrupts
+ */
+#define TXINTGROUP (EMAC_INT_TX_UNDERRUN | EMAC_INT_TX_ERR | EMAC_INT_TX_DONE)
+
+/** \brief  Signal used for ethernet ISR to signal packet_rx() thread.
+ */
+#define RX_SIGNAL  1
+
+#else
+#define RXINTGROUP 0
+#define TXINTGROUP 0
+#endif
+
+ /** \brief  Structure of a TX/RX descriptor
+ */
+typedef struct
+{
+	volatile u32_t packet;        /**< Pointer to buffer */
+	volatile u32_t control;       /**< Control word */
+} LPC_TXRX_DESC_T;
+
+/** \brief  Structure of a RX status entry
+ */
+typedef struct
+{
+	volatile u32_t statusinfo;   /**< RX status word */
+	volatile u32_t statushashcrc; /**< RX hash CRC */
+} LPC_TXRX_STATUS_T;
+
+/* LPC EMAC driver data structure */
+struct lpc_enetdata {
+    /* prxs must be 8 byte aligned! */
+	LPC_TXRX_STATUS_T prxs[LPC_NUM_BUFF_RXDESCS]; /**< Pointer to RX statuses */
+	struct netif *netif;        /**< Reference back to LWIP parent netif */
+	LPC_TXRX_DESC_T ptxd[LPC_NUM_BUFF_TXDESCS];   /**< Pointer to TX descriptor list */
+	LPC_TXRX_STATUS_T ptxs[LPC_NUM_BUFF_TXDESCS]; /**< Pointer to TX statuses */
+	LPC_TXRX_DESC_T prxd[LPC_NUM_BUFF_RXDESCS];   /**< Pointer to RX descriptor list */
+	struct pbuf *rxb[LPC_NUM_BUFF_RXDESCS]; /**< RX pbuf pointer list, zero-copy mode */
+	u32_t rx_fill_desc_index; /**< RX descriptor next available index */
+	volatile u32_t rx_free_descs; /**< Count of free RX descriptors */
+	struct pbuf *txb[LPC_NUM_BUFF_TXDESCS]; /**< TX pbuf pointer list, zero-copy mode */
+	u32_t lpc_last_tx_idx; /**< TX last descriptor index, zero-copy mode */
+#if NO_SYS == 0
+	sys_thread_t RxThread; /**< RX receive thread data object pointer */
+	sys_sem_t TxCleanSem; /**< TX cleanup thread wakeup semaphore */
+	sys_mutex_t TXLockMutex; /**< TX critical section mutex */
+	sys_sem_t xTXDCountSem; /**< TX free buffer counting semaphore */
+#endif
+};
+
+#if defined(TARGET_LPC4088) || defined(TARGET_LPC4088_DM)
+#  if defined (__ICCARM__)
+#     define ETHMEM_SECTION
+#  elif defined(TOOLCHAIN_GCC_CR)
+#     define ETHMEM_SECTION __attribute__((section(".data.$RamPeriph32"), aligned))
+#  else
+#     define ETHMEM_SECTION __attribute__((section("AHBSRAM1"),aligned))
+#  endif
+#elif defined(TARGET_LPC1768)
+#  if defined(TOOLCHAIN_GCC_ARM)
+#     define ETHMEM_SECTION __attribute__((section("AHBSRAM1"),aligned))
+#  endif
+#endif
+
+#ifndef ETHMEM_SECTION
+#define ETHMEM_SECTION ALIGNED(8)
+#endif
+
+/** \brief  LPC EMAC driver work data
+ */
+ETHMEM_SECTION struct lpc_enetdata lpc_enetdata;
+
+/** \brief  Queues a pbuf into the RX descriptor list
+ *
+ *  \param[in] lpc_enetif Pointer to the drvier data structure
+ *  \param[in] p            Pointer to pbuf to queue
+ */
+static void lpc_rxqueue_pbuf(struct lpc_enetdata *lpc_enetif, struct pbuf *p)
+{
+	u32_t idx;
+
+	/* Get next free descriptor index */
+	idx = lpc_enetif->rx_fill_desc_index;
+
+	/* Setup descriptor and clear statuses */
+	lpc_enetif->prxd[idx].control = EMAC_RCTRL_INT | ((u32_t) (p->len - 1));
+	lpc_enetif->prxd[idx].packet = (u32_t) p->payload;
+	lpc_enetif->prxs[idx].statusinfo = 0xFFFFFFFF;
+	lpc_enetif->prxs[idx].statushashcrc = 0xFFFFFFFF;
+
+	/* Save pbuf pointer for push to network layer later */
+	lpc_enetif->rxb[idx] = p;
+
+	/* Wrap at end of descriptor list */
+	idx++;
+	if (idx >= LPC_NUM_BUFF_RXDESCS)
+		idx = 0;
+
+	/* Queue descriptor(s) */
+	lpc_enetif->rx_free_descs -= 1;
+	lpc_enetif->rx_fill_desc_index = idx;
+	LPC_EMAC->RxConsumeIndex = idx;
+
+	LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+		("lpc_rxqueue_pbuf: pbuf packet queued: %p (free desc=%d)\n", p,
+			lpc_enetif->rx_free_descs));
+}
+
+/** \brief  Attempt to allocate and requeue a new pbuf for RX
+ *
+ *  \param[in]     netif Pointer to the netif structure
+ *  \returns         1 if a packet was allocated and requeued, otherwise 0
+ */
+s32_t lpc_rx_queue(struct netif *netif)
+{
+	struct lpc_enetdata *lpc_enetif = netif->state;
+	struct pbuf *p;
+	s32_t queued = 0;
+
+	/* Attempt to requeue as many packets as possible */
+	while (lpc_enetif->rx_free_descs > 0) {
+		/* Allocate a pbuf from the pool. We need to allocate at the
+		   maximum size as we don't know the size of the yet to be
+		   received packet. */
+		p = pbuf_alloc(PBUF_RAW, (u16_t) EMAC_ETH_MAX_FLEN, PBUF_RAM);
+		if (p == NULL) {
+			LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+				("lpc_rx_queue: could not allocate RX pbuf (free desc=%d)\n",
+				lpc_enetif->rx_free_descs));
+			return queued;
+		}
+
+		/* pbufs allocated from the RAM pool should be non-chained. */
+		LWIP_ASSERT("lpc_rx_queue: pbuf is not contiguous (chained)",
+			pbuf_clen(p) <= 1);
+
+		/* Queue packet */
+		lpc_rxqueue_pbuf(lpc_enetif, p);
+
+		/* Update queued count */
+		queued++;
+	}
+
+	return queued;
+}
+
+/** \brief  Sets up the RX descriptor ring buffers.
+ *
+ *  This function sets up the descriptor list used for receive packets.
+ *
+ *  \param[in]  lpc_enetif  Pointer to driver data structure
+ *  \returns                   Always returns ERR_OK
+ */
+static err_t lpc_rx_setup(struct lpc_enetdata *lpc_enetif)
+{
+	/* Setup pointers to RX structures */
+	LPC_EMAC->RxDescriptor = (u32_t) &lpc_enetif->prxd[0];
+	LPC_EMAC->RxStatus = (u32_t) &lpc_enetif->prxs[0];
+	LPC_EMAC->RxDescriptorNumber = LPC_NUM_BUFF_RXDESCS - 1;
+
+	lpc_enetif->rx_free_descs = LPC_NUM_BUFF_RXDESCS;
+	lpc_enetif->rx_fill_desc_index = 0;
+
+	/* Build RX buffer and descriptors */
+	lpc_rx_queue(lpc_enetif->netif);
+
+	return ERR_OK;
+}
+
+/** \brief  Allocates a pbuf and returns the data from the incoming packet.
+ *
+ *  \param[in] netif the lwip network interface structure for this lpc_enetif
+ *  \return a pbuf filled with the received packet (including MAC header)
+ *         NULL on memory error
+ */
+static struct pbuf *lpc_low_level_input(struct netif *netif)
+{
+	struct lpc_enetdata *lpc_enetif = netif->state;
+	struct pbuf *p = NULL;
+	u32_t idx, length;
+	u16_t origLength;
+
+#ifdef LOCK_RX_THREAD
+#if NO_SYS == 0
+	/* Get exclusive access */
+	sys_mutex_lock(&lpc_enetif->TXLockMutex);
+#endif
+#endif
+
+	/* Monitor RX overrun status. This should never happen unless
+	   (possibly) the internal bus is behing held up by something.
+	   Unless your system is running at a very low clock speed or
+	   there are possibilities that the internal buses may be held
+	   up for a long time, this can probably safely be removed. */
+	if (LPC_EMAC->IntStatus & EMAC_INT_RX_OVERRUN) {
+		LINK_STATS_INC(link.err);
+		LINK_STATS_INC(link.drop);
+
+		/* Temporarily disable RX */
+		LPC_EMAC->MAC1 &= ~EMAC_MAC1_REC_EN;
+
+		/* Reset the RX side */
+		LPC_EMAC->MAC1 |= EMAC_MAC1_RES_RX;
+		LPC_EMAC->IntClear = EMAC_INT_RX_OVERRUN;
+
+		/* De-allocate all queued RX pbufs */
+		for (idx = 0; idx < LPC_NUM_BUFF_RXDESCS; idx++) {
+			if (lpc_enetif->rxb[idx] != NULL) {
+				pbuf_free(lpc_enetif->rxb[idx]);
+				lpc_enetif->rxb[idx] = NULL;
+			}
+		}
+
+		/* Start RX side again */
+		lpc_rx_setup(lpc_enetif);
+
+		/* Re-enable RX */
+		LPC_EMAC->MAC1 |= EMAC_MAC1_REC_EN;
+
+#ifdef LOCK_RX_THREAD
+#if NO_SYS == 0
+		sys_mutex_unlock(&lpc_enetif->TXLockMutex);
+#endif
+#endif
+
+		return NULL;
+	}
+
+	/* Determine if a frame has been received */
+	length = 0;
+	idx = LPC_EMAC->RxConsumeIndex;
+	if (LPC_EMAC->RxProduceIndex != idx) {
+		/* Handle errors */
+		if (lpc_enetif->prxs[idx].statusinfo & (EMAC_RINFO_CRC_ERR |
+			EMAC_RINFO_SYM_ERR | EMAC_RINFO_ALIGN_ERR | EMAC_RINFO_LEN_ERR)) {
+#if LINK_STATS
+			if (lpc_enetif->prxs[idx].statusinfo & (EMAC_RINFO_CRC_ERR |
+				EMAC_RINFO_SYM_ERR | EMAC_RINFO_ALIGN_ERR))
+				LINK_STATS_INC(link.chkerr);
+			if (lpc_enetif->prxs[idx].statusinfo & EMAC_RINFO_LEN_ERR)
+				LINK_STATS_INC(link.lenerr);
+#endif
+
+			/* Drop the frame */
+			LINK_STATS_INC(link.drop);
+
+			/* Re-queue the pbuf for receive */
+			lpc_enetif->rx_free_descs++;
+			p = lpc_enetif->rxb[idx];
+			lpc_enetif->rxb[idx] = NULL;
+			lpc_rxqueue_pbuf(lpc_enetif, p);
+
+			LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+				("lpc_low_level_input: Packet dropped with errors (0x%x)\n",
+				lpc_enetif->prxs[idx].statusinfo));
+
+			p = NULL;
+		} else {
+			/* A packet is waiting, get length */
+			length = (lpc_enetif->prxs[idx].statusinfo & 0x7FF) + 1;
+
+			/* Zero-copy */
+			p = lpc_enetif->rxb[idx];
+			origLength = p->len;
+			p->len = (u16_t) length;
+
+			/* Free pbuf from descriptor */
+			lpc_enetif->rxb[idx] = NULL;
+			lpc_enetif->rx_free_descs++;
+
+			/* Attempt to queue new buffer(s) */
+			if (lpc_rx_queue(lpc_enetif->netif) == 0) {
+    			/* Drop the frame due to OOM. */
+    			LINK_STATS_INC(link.drop);
+
+    			/* Re-queue the pbuf for receive */
+    			p->len = origLength;
+    			lpc_rxqueue_pbuf(lpc_enetif, p);
+
+    			LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+    				("lpc_low_level_input: Packet index %d dropped for OOM\n",
+    				idx));
+			
+#ifdef LOCK_RX_THREAD
+#if NO_SYS == 0
+        		sys_mutex_unlock(&lpc_enetif->TXLockMutex);
+#endif
+#endif
+
+		        return NULL;
+			}
+
+			LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+				("lpc_low_level_input: Packet received: %p, size %d (index=%d)\n",
+				p, length, idx));
+
+			/* Save size */
+			p->tot_len = (u16_t) length;
+			LINK_STATS_INC(link.recv);
+		}
+	}
+
+#ifdef LOCK_RX_THREAD
+#if NO_SYS == 0
+	sys_mutex_unlock(&lpc_enetif->TXLockMutex);
+#endif
+#endif
+
+	return p;
+}
+
+/** \brief  Attempt to read a packet from the EMAC interface.
+ *
+ *  \param[in] netif the lwip network interface structure for this lpc_enetif
+ */
+void lpc_enetif_input(struct netif *netif)
+{
+	struct eth_hdr *ethhdr;
+	struct pbuf *p;
+
+	/* move received packet into a new pbuf */
+	p = lpc_low_level_input(netif);
+	if (p == NULL)
+		return;
+
+	/* points to packet payload, which starts with an Ethernet header */
+	ethhdr = p->payload;
+
+	switch (htons(ethhdr->type)) {
+		case ETHTYPE_IP:
+		case ETHTYPE_ARP:
+#if PPPOE_SUPPORT
+		case ETHTYPE_PPPOEDISC:
+		case ETHTYPE_PPPOE:
+#endif /* PPPOE_SUPPORT */
+			/* full packet send to tcpip_thread to process */
+			if (netif->input(p, netif) != ERR_OK) {
+				LWIP_DEBUGF(NETIF_DEBUG, ("lpc_enetif_input: IP input error\n"));
+				/* Free buffer */
+				pbuf_free(p);
+			}
+			break;
+
+		default:
+			/* Return buffer */
+			pbuf_free(p);
+			break;
+	}
+}
+
+/** \brief  Determine if the passed address is usable for the ethernet
+ *          DMA controller.
+ *
+ *  \param[in] addr Address of packet to check for DMA safe operation
+ *  \return          1 if the packet address is not safe, otherwise 0
+ */
+static s32_t lpc_packet_addr_notsafe(void *addr) {
+	/* Check for legal address ranges */
+#if defined(TARGET_LPC1768)
+	if ((((u32_t) addr >= 0x2007C000) && ((u32_t) addr < 0x20083FFF))) {
+#elif defined(TARGET_LPC4088) || defined(TARGET_LPC4088_DM)
+	if ((((u32_t) addr >= 0x20000000) && ((u32_t) addr < 0x20007FFF))) {
+#endif
+	    return 0;
+	}
+	return 1;
+}
+
+/** \brief  Sets up the TX descriptor ring buffers.
+ *
+ *  This function sets up the descriptor list used for transmit packets.
+ *
+ *  \param[in]      lpc_enetif  Pointer to driver data structure
+ */
+static err_t lpc_tx_setup(struct lpc_enetdata *lpc_enetif)
+{
+	s32_t idx;
+
+	/* Build TX descriptors for local buffers */
+	for (idx = 0; idx < LPC_NUM_BUFF_TXDESCS; idx++) {
+		lpc_enetif->ptxd[idx].control = 0;
+		lpc_enetif->ptxs[idx].statusinfo = 0xFFFFFFFF;
+	}
+
+	/* Setup pointers to TX structures */
+	LPC_EMAC->TxDescriptor = (u32_t) &lpc_enetif->ptxd[0];
+	LPC_EMAC->TxStatus = (u32_t) &lpc_enetif->ptxs[0];
+	LPC_EMAC->TxDescriptorNumber = LPC_NUM_BUFF_TXDESCS - 1;
+
+	lpc_enetif->lpc_last_tx_idx = 0;
+
+	return ERR_OK;
+}
+
+/** \brief  Free TX buffers that are complete
+ *
+ *  \param[in] lpc_enetif  Pointer to driver data structure
+ *  \param[in] cidx  EMAC current descriptor comsumer index
+ */
+static void lpc_tx_reclaim_st(struct lpc_enetdata *lpc_enetif, u32_t cidx)
+{
+#if NO_SYS == 0
+	/* Get exclusive access */
+	sys_mutex_lock(&lpc_enetif->TXLockMutex);
+#endif
+
+	while (cidx != lpc_enetif->lpc_last_tx_idx) {
+		if (lpc_enetif->txb[lpc_enetif->lpc_last_tx_idx] != NULL) {
+			LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+				("lpc_tx_reclaim_st: Freeing packet %p (index %d)\n",
+				lpc_enetif->txb[lpc_enetif->lpc_last_tx_idx],
+				lpc_enetif->lpc_last_tx_idx));
+			pbuf_free(lpc_enetif->txb[lpc_enetif->lpc_last_tx_idx]);
+		 	lpc_enetif->txb[lpc_enetif->lpc_last_tx_idx] = NULL;
+		}
+
+#if NO_SYS == 0
+		osSemaphoreRelease(lpc_enetif->xTXDCountSem.id);
+#endif
+		lpc_enetif->lpc_last_tx_idx++;
+		if (lpc_enetif->lpc_last_tx_idx >= LPC_NUM_BUFF_TXDESCS)
+			lpc_enetif->lpc_last_tx_idx = 0;
+	}
+
+#if NO_SYS == 0
+	/* Restore access */
+	sys_mutex_unlock(&lpc_enetif->TXLockMutex);
+#endif
+}
+
+/** \brief  User call for freeingTX buffers that are complete
+ *
+ *  \param[in] netif the lwip network interface structure for this lpc_enetif
+ */
+void lpc_tx_reclaim(struct netif *netif)
+{
+	lpc_tx_reclaim_st((struct lpc_enetdata *) netif->state,
+		LPC_EMAC->TxConsumeIndex);
+}
+
+ /** \brief  Polls if an available TX descriptor is ready. Can be used to
+ *           determine if the low level transmit function will block.
+ *
+ *  \param[in] netif the lwip network interface structure for this lpc_enetif
+ *  \return 0 if no descriptors are read, or >0
+ */
+s32_t lpc_tx_ready(struct netif *netif)
+{
+	s32_t fb;
+	u32_t idx, cidx;
+
+	cidx = LPC_EMAC->TxConsumeIndex;
+	idx = LPC_EMAC->TxProduceIndex;
+
+	/* Determine number of free buffers */
+	if (idx == cidx)
+		fb = LPC_NUM_BUFF_TXDESCS;
+	else if (cidx > idx)
+		fb = (LPC_NUM_BUFF_TXDESCS - 1) -
+			((idx + LPC_NUM_BUFF_TXDESCS) - cidx);
+	else
+		fb = (LPC_NUM_BUFF_TXDESCS - 1) - (cidx - idx);
+
+	return fb;
+}
+
+/** \brief  Low level output of a packet. Never call this from an
+ *          interrupt context, as it may block until TX descriptors
+ *          become available.
+ *
+ *  \param[in] netif the lwip network interface structure for this lpc_enetif
+ *  \param[in] p the MAC packet to send (e.g. IP packet including MAC addresses and type)
+ *  \return ERR_OK if the packet could be sent or an err_t value if the packet couldn't be sent
+ */
+static err_t lpc_low_level_output(struct netif *netif, struct pbuf *p)
+{
+	struct lpc_enetdata *lpc_enetif = netif->state;
+	struct pbuf *q;
+	u8_t *dst;
+    u32_t idx, notdmasafe = 0;
+	struct pbuf *np;
+	s32_t dn;
+
+	/* Zero-copy TX buffers may be fragmented across mutliple payload
+	   chains. Determine the number of descriptors needed for the
+	   transfer. The pbuf chaining can be a mess! */
+	dn = (s32_t) pbuf_clen(p);
+
+	/* Test to make sure packet addresses are DMA safe. A DMA safe
+	   address is once that uses external memory or periphheral RAM.
+	   IRAM and FLASH are not safe! */
+	for (q = p; q != NULL; q = q->next)
+		notdmasafe += lpc_packet_addr_notsafe(q->payload);
+
+#if LPC_TX_PBUF_BOUNCE_EN==1
+	/* If the pbuf is not DMA safe, a new bounce buffer (pbuf) will be
+	   created that will be used instead. This requires an copy from the
+	   non-safe DMA region to the new pbuf */
+	if (notdmasafe) {
+		/* Allocate a pbuf in DMA memory */
+		np = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
+		if (np == NULL)
+			return ERR_MEM;
+
+		/* This buffer better be contiguous! */
+		LWIP_ASSERT("lpc_low_level_output: New transmit pbuf is chained",
+			(pbuf_clen(np) == 1));
+
+		/* Copy to DMA safe pbuf */
+		dst = (u8_t *) np->payload;
+	 	for(q = p; q != NULL; q = q->next) {
+			/* Copy the buffer to the descriptor's buffer */
+	  		MEMCPY(dst, (u8_t *) q->payload, q->len);
+		  dst += q->len;
+		}
+		np->len = p->tot_len;
+
+		LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+			("lpc_low_level_output: Switched to DMA safe buffer, old=%p, new=%p\n",
+			q, np));
+
+		/* use the new buffer for descrptor queueing. The original pbuf will
+		   be de-allocated outsuide this driver. */
+		p = np;
+		dn = 1;
+	}
+#else
+	if (notdmasafe)
+		LWIP_ASSERT("lpc_low_level_output: Not a DMA safe pbuf",
+			(notdmasafe == 0));
+#endif
+
+	/* Wait until enough descriptors are available for the transfer. */
+	/* THIS WILL BLOCK UNTIL THERE ARE ENOUGH DESCRIPTORS AVAILABLE */
+	while (dn > lpc_tx_ready(netif))
+#if NO_SYS == 0
+	    osSemaphoreWait(lpc_enetif->xTXDCountSem.id, osWaitForever);
+#else
+		osDelay(1);
+#endif
+
+	/* Get free TX buffer index */
+	idx = LPC_EMAC->TxProduceIndex;
+
+#if NO_SYS == 0
+	/* Get exclusive access */
+	sys_mutex_lock(&lpc_enetif->TXLockMutex);
+#endif
+
+	/* Prevent LWIP from de-allocating this pbuf. The driver will
+	   free it once it's been transmitted. */
+	if (!notdmasafe)
+		pbuf_ref(p);
+
+	/* Setup transfers */
+	q = p;
+	while (dn > 0) {
+		dn--;
+
+		/* Only save pointer to free on last descriptor */
+		if (dn == 0) {
+			/* Save size of packet and signal it's ready */
+			lpc_enetif->ptxd[idx].control = (q->len - 1) | EMAC_TCTRL_INT |
+				EMAC_TCTRL_LAST;
+            lpc_enetif->txb[idx] = p;
+		}
+		else {
+			/* Save size of packet, descriptor is not last */
+			lpc_enetif->ptxd[idx].control = (q->len - 1) | EMAC_TCTRL_INT;
+			lpc_enetif->txb[idx] = NULL;
+		}
+
+		LWIP_DEBUGF(UDP_LPC_EMAC | LWIP_DBG_TRACE,
+			("lpc_low_level_output: pbuf packet(%p) sent, chain#=%d,"
+			" size = %d (index=%d)\n", q->payload, dn, q->len, idx));
+
+		lpc_enetif->ptxd[idx].packet = (u32_t) q->payload;
+
+		q = q->next;
+
+		idx++;
+		if (idx >= LPC_NUM_BUFF_TXDESCS)
+			idx = 0;
+	}
+
+	LPC_EMAC->TxProduceIndex = idx;
+
+	LINK_STATS_INC(link.xmit);
+
+#if NO_SYS == 0
+	/* Restore access */
+	sys_mutex_unlock(&lpc_enetif->TXLockMutex);
+#endif
+
+	return ERR_OK;
+}
+
+/** \brief  LPC EMAC interrupt handler.
+ *
+ *  This function handles the transmit, receive, and error interrupt of
+ *  the LPC177x_8x. This is meant to be used when NO_SYS=0.
+ */
+void ENET_IRQHandler(void)
+{
+#if NO_SYS == 1
+	/* Interrupts are not used without an RTOS */
+    NVIC_DisableIRQ(ENET_IRQn);
+#else
+	uint32_t ints;
+
+	/* Interrupts are of 2 groups - transmit or receive. Based on the
+	   interrupt, kick off the receive or transmit (cleanup) task */
+
+	/* Get pending interrupts */
+	ints = LPC_EMAC->IntStatus;
+
+	if (ints & RXINTGROUP) {
+        /* RX group interrupt(s): Give signal to wakeup RX receive task.*/
+        osSignalSet(lpc_enetdata.RxThread->id, RX_SIGNAL);
+    }
+
+    if (ints & TXINTGROUP) {
+        /* TX group interrupt(s): Give semaphore to wakeup TX cleanup task. */
+        sys_sem_signal(&lpc_enetdata.TxCleanSem);
+    }
+
+	/* Clear pending interrupts */
+	LPC_EMAC->IntClear = ints;
+#endif
+}
+
+#if NO_SYS == 0
+/** \brief  Packet reception task
+ *
+ * This task is called when a packet is received. It will
+ * pass the packet to the LWIP core.
+ *
+ *  \param[in] pvParameters Not used yet
+ */
+static void packet_rx(void* pvParameters) {
+    struct lpc_enetdata *lpc_enetif = pvParameters;
+
+    while (1) {
+        /* Wait for receive task to wakeup */
+        osSignalWait(RX_SIGNAL, osWaitForever);
+
+        /* Process packets until all empty */
+        while (LPC_EMAC->RxConsumeIndex != LPC_EMAC->RxProduceIndex)
+            lpc_enetif_input(lpc_enetif->netif);
+    }
+}
+
+/** \brief  Transmit cleanup task
+ *
+ * This task is called when a transmit interrupt occurs and
+ * reclaims the pbuf and descriptor used for the packet once
+ * the packet has been transferred.
+ *
+ *  \param[in] pvParameters Not used yet
+ */
+static void packet_tx(void* pvParameters) {
+    struct lpc_enetdata *lpc_enetif = pvParameters;
+    s32_t idx;
+
+    while (1) {
+        /* Wait for transmit cleanup task to wakeup */
+        sys_arch_sem_wait(&lpc_enetif->TxCleanSem, 0);
+
+        /* Error handling for TX underruns. This should never happen unless
+           something is holding the bus or the clocks are going too slow. It
+            can probably be safely removed. */
+        if (LPC_EMAC->IntStatus & EMAC_INT_TX_UNDERRUN) {
+            LINK_STATS_INC(link.err);
+            LINK_STATS_INC(link.drop);
+
+#if NO_SYS == 0
+            /* Get exclusive access */
+            sys_mutex_lock(&lpc_enetif->TXLockMutex);
+#endif
+            /* Reset the TX side */
+            LPC_EMAC->MAC1 |= EMAC_MAC1_RES_TX;
+            LPC_EMAC->IntClear = EMAC_INT_TX_UNDERRUN;
+
+            /* De-allocate all queued TX pbufs */
+            for (idx = 0; idx < LPC_NUM_BUFF_TXDESCS; idx++) {
+                if (lpc_enetif->txb[idx] != NULL) {
+                    pbuf_free(lpc_enetif->txb[idx]);
+                    lpc_enetif->txb[idx] = NULL;
+                }
+            }
+
+#if NO_SYS == 0
+            /* Restore access */
+            sys_mutex_unlock(&lpc_enetif->TXLockMutex);
+#endif
+            /* Start TX side again */
+            lpc_tx_setup(lpc_enetif);
+        } else {
+            /* Free TX buffers that are done sending */
+            lpc_tx_reclaim(lpc_enetdata.netif);
+        }
+    }
+}
+#endif
+
+/** \brief  Low level init of the MAC and PHY.
+ *
+ *  \param[in]      netif  Pointer to LWIP netif structure
+ */
+static err_t low_level_init(struct netif *netif)
+{
+	struct lpc_enetdata *lpc_enetif = netif->state;
+	err_t err = ERR_OK;
+
+	/* Enable MII clocking */
+	LPC_SC->PCONP |= CLKPWR_PCONP_PCENET;
+
+#if defined(TARGET_LPC1768)
+	LPC_PINCON->PINSEL2 = 0x50150105;                  /* Enable P1 Ethernet Pins. */
+	LPC_PINCON->PINSEL3 = (LPC_PINCON->PINSEL3 & ~0x0000000F) | 0x00000005;
+#elif defined(TARGET_LPC4088) || defined(TARGET_LPC4088_DM)
+  LPC_IOCON->P1_0  &= ~0x07;    /*  ENET I/O config */
+  LPC_IOCON->P1_0  |= 0x01;     /* ENET_TXD0 */
+  LPC_IOCON->P1_1  &= ~0x07;
+  LPC_IOCON->P1_1  |= 0x01;     /* ENET_TXD1 */
+  LPC_IOCON->P1_4  &= ~0x07;
+  LPC_IOCON->P1_4  |= 0x01;     /* ENET_TXEN */
+  LPC_IOCON->P1_8  &= ~0x07;
+  LPC_IOCON->P1_8  |= 0x01;     /* ENET_CRS */
+  LPC_IOCON->P1_9  &= ~0x07;
+  LPC_IOCON->P1_9  |= 0x01;     /* ENET_RXD0 */
+  LPC_IOCON->P1_10 &= ~0x07;
+  LPC_IOCON->P1_10 |= 0x01;     /* ENET_RXD1 */
+  LPC_IOCON->P1_14 &= ~0x07;
+  LPC_IOCON->P1_14 |= 0x01;     /* ENET_RX_ER */
+  LPC_IOCON->P1_15 &= ~0x07;
+  LPC_IOCON->P1_15 |= 0x01;     /* ENET_REF_CLK */
+  LPC_IOCON->P1_16 &= ~0x07;    /* ENET/PHY I/O config */
+  LPC_IOCON->P1_16 |= 0x01;     /* ENET_MDC */
+  LPC_IOCON->P1_17 &= ~0x07;
+  LPC_IOCON->P1_17 |= 0x01;     /* ENET_MDIO */
+#endif
+
+	/* Reset all MAC logic */
+	LPC_EMAC->MAC1 = EMAC_MAC1_RES_TX | EMAC_MAC1_RES_MCS_TX |
+		EMAC_MAC1_RES_RX | EMAC_MAC1_RES_MCS_RX | EMAC_MAC1_SIM_RES |
+		EMAC_MAC1_SOFT_RES;
+	LPC_EMAC->Command = EMAC_CR_REG_RES | EMAC_CR_TX_RES | EMAC_CR_RX_RES |
+		EMAC_CR_PASS_RUNT_FRM;
+	osDelay(10);
+
+	/* Initial MAC initialization */
+	LPC_EMAC->MAC1 = EMAC_MAC1_PASS_ALL;
+	LPC_EMAC->MAC2 = EMAC_MAC2_CRC_EN | EMAC_MAC2_PAD_EN |
+		EMAC_MAC2_VLAN_PAD_EN;
+	LPC_EMAC->MAXF = EMAC_ETH_MAX_FLEN;
+
+	/* Set RMII management clock rate to lowest speed */
+	LPC_EMAC->MCFG = EMAC_MCFG_CLK_SEL(11) | EMAC_MCFG_RES_MII;
+	LPC_EMAC->MCFG &= ~EMAC_MCFG_RES_MII;
+
+	/* Maximum number of retries, 0x37 collision window, gap */
+	LPC_EMAC->CLRT = EMAC_CLRT_DEF;
+	LPC_EMAC->IPGR = EMAC_IPGR_P1_DEF | EMAC_IPGR_P2_DEF;
+
+#if LPC_EMAC_RMII
+	/* RMII setup */
+	LPC_EMAC->Command = EMAC_CR_PASS_RUNT_FRM | EMAC_CR_RMII;
+#else
+	/* MII setup */
+	LPC_EMAC->CR = EMAC_CR_PASS_RUNT_FRM;
+#endif
+
+	/* Initialize the PHY and reset */
+    err = lpc_phy_init(netif, LPC_EMAC_RMII);
+	if (err != ERR_OK)
+ 		return err;
+
+	/* Save station address */
+	LPC_EMAC->SA2 = (u32_t) netif->hwaddr[0] |
+		(((u32_t) netif->hwaddr[1]) << 8);
+	LPC_EMAC->SA1 = (u32_t) netif->hwaddr[2] |
+		(((u32_t) netif->hwaddr[3]) << 8);
+	LPC_EMAC->SA0 = (u32_t) netif->hwaddr[4] |
+		(((u32_t) netif->hwaddr[5]) << 8);
+
+	/* Setup transmit and receive descriptors */
+	if (lpc_tx_setup(lpc_enetif) != ERR_OK)
+		return ERR_BUF;
+	if (lpc_rx_setup(lpc_enetif) != ERR_OK)
+		return ERR_BUF;
+
+	/* Enable packet reception */
+#if IP_SOF_BROADCAST_RECV
+	LPC_EMAC->RxFilterCtrl = EMAC_RFC_PERFECT_EN | EMAC_RFC_BCAST_EN | EMAC_RFC_MCAST_EN;
+#else
+	LPC_EMAC->RxFilterCtrl = EMAC_RFC_PERFECT_EN;
+#endif
+
+	/* Clear and enable rx/tx interrupts */
+	LPC_EMAC->IntClear = 0xFFFF;
+	LPC_EMAC->IntEnable = RXINTGROUP | TXINTGROUP;
+
+	/* Enable RX and TX */
+	LPC_EMAC->Command |= EMAC_CR_RX_EN | EMAC_CR_TX_EN;
+	LPC_EMAC->MAC1 |= EMAC_MAC1_REC_EN;
+
+	return err;
+}
+
+/* This function provides a method for the PHY to setup the EMAC
+   for the PHY negotiated duplex mode */
+void lpc_emac_set_duplex(int full_duplex)
+{
+	if (full_duplex) {
+		LPC_EMAC->MAC2    |= EMAC_MAC2_FULL_DUP;
+		LPC_EMAC->Command |= EMAC_CR_FULL_DUP;
+		LPC_EMAC->IPGT     = EMAC_IPGT_FULL_DUP;
+	} else {
+		LPC_EMAC->MAC2    &= ~EMAC_MAC2_FULL_DUP;
+		LPC_EMAC->Command &= ~EMAC_CR_FULL_DUP;
+		LPC_EMAC->IPGT = EMAC_IPGT_HALF_DUP;
+	}
+}
+
+/* This function provides a method for the PHY to setup the EMAC
+   for the PHY negotiated bit rate */
+void lpc_emac_set_speed(int mbs_100)
+{
+	if (mbs_100)
+		LPC_EMAC->SUPP = EMAC_SUPP_SPEED;
+	else
+		LPC_EMAC->SUPP = 0;
+}
+
+/**
+ * This function is the ethernet packet send function. It calls
+ * etharp_output after checking link status.
+ *
+ * \param[in] netif the lwip network interface structure for this lpc_enetif
+ * \param[in] q Pointer to pbug to send
+ * \param[in] ipaddr IP address
+ * \return ERR_OK or error code
+ */
+err_t lpc_etharp_output(struct netif *netif, struct pbuf *q,
+	ip_addr_t *ipaddr)
+{
+	/* Only send packet is link is up */
+	if (netif->flags & NETIF_FLAG_LINK_UP)
+		return etharp_output(netif, q, ipaddr);
+
+	return ERR_CONN;
+}
+
+#if NO_SYS == 0
+/* periodic PHY status update */
+void phy_update(void const *nif) {
+    lpc_phy_sts_sm((struct netif*)nif);
+}
+osTimerDef(phy_update, phy_update);
+#endif
+
+/**
+ * Should be called at the beginning of the program to set up the
+ * network interface.
+ *
+ * This function should be passed as a parameter to netif_add().
+ *
+ * @param[in] netif the lwip network interface structure for this lpc_enetif
+ * @return ERR_OK if the loopif is initialized
+ *         ERR_MEM if private data couldn't be allocated
+ *         any other err_t on error
+ */
+err_t eth_arch_enetif_init(struct netif *netif)
+{
+	err_t err;
+
+	LWIP_ASSERT("netif != NULL", (netif != NULL));
+
+	lpc_enetdata.netif = netif;
+
+	/* set MAC hardware address */
+#if (MBED_MAC_ADDRESS_SUM != MBED_MAC_ADDR_INTERFACE)
+	netif->hwaddr[0] = MBED_MAC_ADDR_0;
+	netif->hwaddr[1] = MBED_MAC_ADDR_1;
+	netif->hwaddr[2] = MBED_MAC_ADDR_2;
+	netif->hwaddr[3] = MBED_MAC_ADDR_3;
+	netif->hwaddr[4] = MBED_MAC_ADDR_4;
+	netif->hwaddr[5] = MBED_MAC_ADDR_5;
+#else
+	mbed_mac_address((char *)netif->hwaddr);
+#endif
+	netif->hwaddr_len = ETHARP_HWADDR_LEN;
+
+ 	/* maximum transfer unit */
+	netif->mtu = 1500;
+
+	/* device capabilities */
+	netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET | NETIF_FLAG_IGMP;
+
+	/* Initialize the hardware */
+	netif->state = &lpc_enetdata;
+	err = low_level_init(netif);
+	if (err != ERR_OK)
+		return err;
+
+#if LWIP_NETIF_HOSTNAME
+	/* Initialize interface hostname */
+	netif->hostname = "lwiplpc";
+#endif /* LWIP_NETIF_HOSTNAME */
+
+	netif->name[0] = 'e';
+	netif->name[1] = 'n';
+
+	netif->output = lpc_etharp_output;
+	netif->linkoutput = lpc_low_level_output;
+
+    /* CMSIS-RTOS, start tasks */
+#if NO_SYS == 0
+#ifdef CMSIS_OS_RTX
+    memset(lpc_enetdata.xTXDCountSem.data, 0, sizeof(lpc_enetdata.xTXDCountSem.data));
+    lpc_enetdata.xTXDCountSem.def.semaphore = lpc_enetdata.xTXDCountSem.data;
+#endif
+    lpc_enetdata.xTXDCountSem.id = osSemaphoreCreate(&lpc_enetdata.xTXDCountSem.def, LPC_NUM_BUFF_TXDESCS);
+	LWIP_ASSERT("xTXDCountSem creation error", (lpc_enetdata.xTXDCountSem.id != NULL));
+
+	err = sys_mutex_new(&lpc_enetdata.TXLockMutex);
+	LWIP_ASSERT("TXLockMutex creation error", (err == ERR_OK));
+
+	/* Packet receive task */
+	lpc_enetdata.RxThread = sys_thread_new("receive_thread", packet_rx, netif->state, DEFAULT_THREAD_STACKSIZE, RX_PRIORITY);
+	LWIP_ASSERT("RxThread creation error", (lpc_enetdata.RxThread));
+
+	/* Transmit cleanup task */
+	err = sys_sem_new(&lpc_enetdata.TxCleanSem, 0);
+	LWIP_ASSERT("TxCleanSem creation error", (err == ERR_OK));
+	sys_thread_new("txclean_thread", packet_tx, netif->state, DEFAULT_THREAD_STACKSIZE, TX_PRIORITY);
+
+	/* periodic PHY status update */
+	osTimerId phy_timer = osTimerCreate(osTimer(phy_update), osTimerPeriodic, (void *)netif);
+	osTimerStart(phy_timer, 250);
+#endif
+
+    return ERR_OK;
+}
+
+void eth_arch_enable_interrupts(void) {
+    NVIC_SetPriority(ENET_IRQn, ((0x01 << 3) | 0x01));
+    NVIC_EnableIRQ(ENET_IRQn);
+}
+
+void eth_arch_disable_interrupts(void) {
+    NVIC_DisableIRQ(ENET_IRQn);
+}
+
+/**
+ * @}
+ */
+
+/* --------------------------------- End Of File ------------------------------ */