V1

Dependents:   EthernetInterface

Fork of lwip-eth by mbed official

Revision:
4:d827a085afd9
Parent:
3:dd8b8f5b449a
Child:
5:698d868a5285
--- a/arch/lpc17_emac.c	Mon Jul 23 11:52:41 2012 +0000
+++ b/arch/lpc17_emac.c	Fri Mar 01 15:30:33 2013 +0000
@@ -1,1043 +1,1045 @@
-/**********************************************************************
-* $Id$        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 "lpc17_emac.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)
-
-#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_sem_t RxSem; /**< RX receive thread wakeup semaphore */
-    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
-};
-
-/** \brief  LPC EMAC driver work data
- */
-ALIGNED(8) struct lpc_enetdata lpc_enetdata;
-
-/* Write a value via the MII link (non-blocking) */
-void lpc_mii_write_noblock(u32_t PhyReg, u32_t Value)
-{
-    /* Write value at PHY address and register */
-    LPC_EMAC->MADR = (LPC_PHYDEF_PHYADDR << 8) | PhyReg;
-    LPC_EMAC->MWTD = Value;
-}
-
-/* Write a value via the MII link (blocking) */
-err_t lpc_mii_write(u32_t PhyReg, u32_t Value)
-{
-    u32_t mst = 250;
-    err_t sts = ERR_OK;
-
-    /* Write value at PHY address and register */
-    lpc_mii_write_noblock(PhyReg, Value);
-
-    /* Wait for unbusy status */
-    while (mst > 0) {
-        sts = LPC_EMAC->MIND;
-        if ((sts & EMAC_MIND_BUSY) == 0)
-            mst = 0;
-        else {
-            mst--;
-            osDelay(1);
-        }
-    }
-
-    if (sts != 0)
-        sts = ERR_TIMEOUT;
-
-    return sts;
-}
-
-/* Reads current MII link busy status */
-u32_t lpc_mii_is_busy(void)
-{
-    return (u32_t) (LPC_EMAC->MIND & EMAC_MIND_BUSY);
-}
-
-/* Starts a read operation via the MII link (non-blocking) */
-u32_t lpc_mii_read_data(void)
-{
-    u32_t data = LPC_EMAC->MRDD;
-    LPC_EMAC->MCMD = 0;
-
-    return data;
-}
-
-/* Starts a read operation via the MII link (non-blocking) */
-void lpc_mii_read_noblock(u32_t PhyReg) 
-{
-    /* Read value at PHY address and register */
-    LPC_EMAC->MADR = (LPC_PHYDEF_PHYADDR << 8) | PhyReg;
-    LPC_EMAC->MCMD = EMAC_MCMD_READ;
-}
-
-/* Read a value via the MII link (blocking) */
-err_t lpc_mii_read(u32_t PhyReg, u32_t *data) 
-{
-    u32_t mst = 250;
-    err_t sts = ERR_OK;
-
-    /* Read value at PHY address and register */
-    lpc_mii_read_noblock(PhyReg);
-
-    /* Wait for unbusy status */
-    while (mst > 0) {
-        sts = LPC_EMAC->MIND & ~EMAC_MIND_MII_LINK_FAIL;
-        if ((sts & EMAC_MIND_BUSY) == 0) {
-            mst = 0;
-            *data = LPC_EMAC->MRDD;
-        } else {
-            mst--;
-            osDelay(1);
-        }
-    }
-
-    LPC_EMAC->MCMD = 0;
-
-    if (sts != 0)
-        sts = ERR_TIMEOUT;
-
-    return sts;
-}
-
-/** \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;
-
-#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));
-        } else {
-            /* A packet is waiting, get length */
-            length = (lpc_enetif->prxs[idx].statusinfo & 0x7FF) + 1;
-
-            /* Zero-copy */
-            p = lpc_enetif->rxb[idx];
-            p->len = (u16_t) length;
-
-            /* Free pbuf from desriptor */
-            lpc_enetif->rxb[idx] = NULL;
-            lpc_enetif->rx_free_descs++;
-
-            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);
-
-            /* Queue new buffer(s) */
-            lpc_rx_queue(lpc_enetif->netif);
-        }
-    }
-
-#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 ((((u32_t) addr >= 0x2007C000) && ((u32_t) addr < 0x20083FFF))) {
-        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;
-    struct pbuf *np;
-    u32_t dn, notdmasafe = 0;
-
-    /* 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 = (u32_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 semaphore to wakeup RX receive task.*/
-        sys_sem_signal(&lpc_enetdata.RxSem);
-    }
-    
-    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 */
-        sys_arch_sem_wait(&lpc_enetif->RxSem, 0);
-        
-        /* 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_RXDESCS; 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;
-    
-    LPC_PINCON->PINSEL2 = 0x50150105;                  /* Enable P1 Ethernet Pins. */
-    LPC_PINCON->PINSEL3 = (LPC_PINCON->PINSEL3 & ~0x0000000F) | 0x00000005;
-    
-    /* 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;
-#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 lpc_enetif_init(struct netif *netif)
-{
-    err_t err;
-
-    LWIP_ASSERT("netif != NULL", (netif != NULL));
-    
-    lpc_enetdata.netif = netif;
-
-    /* set MAC hardware address */
-    mbed_mac_address((char *)netif->hwaddr);
-    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;
-
-    /* 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 */
-    err = sys_sem_new(&lpc_enetdata.RxSem, 0);
-    LWIP_ASSERT("RxSem creation error", (err == ERR_OK));
-    sys_thread_new("receive_thread", packet_rx, netif->state, DEFAULT_THREAD_STACKSIZE, RX_PRIORITY);
-
-    /* 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;
-}
-
-/**
- * @}
- */
-
-/* --------------------------------- End Of File ------------------------------ */
+/**********************************************************************
+* $Id$        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 "lpc17_emac.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)
+
+#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_sem_t RxSem; /**< RX receive thread wakeup semaphore */
+    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
+};
+
+/** \brief  LPC EMAC driver work data
+ */
+ALIGNED(8) struct lpc_enetdata lpc_enetdata;
+
+/* Write a value via the MII link (non-blocking) */
+void lpc_mii_write_noblock(u32_t PhyReg, u32_t Value)
+{
+    /* Write value at PHY address and register */
+    LPC_EMAC->MADR = (LPC_PHYDEF_PHYADDR << 8) | PhyReg;
+    LPC_EMAC->MWTD = Value;
+}
+
+/* Write a value via the MII link (blocking) */
+err_t lpc_mii_write(u32_t PhyReg, u32_t Value)
+{
+    u32_t mst = 250;
+    err_t sts = ERR_OK;
+
+    /* Write value at PHY address and register */
+    lpc_mii_write_noblock(PhyReg, Value);
+
+    /* Wait for unbusy status */
+    while (mst > 0) {
+        sts = LPC_EMAC->MIND;
+        if ((sts & EMAC_MIND_BUSY) == 0)
+            mst = 0;
+        else {
+            mst--;
+            osDelay(1);
+        }
+    }
+
+    if (sts != 0)
+        sts = ERR_TIMEOUT;
+
+    return sts;
+}
+
+/* Reads current MII link busy status */
+u32_t lpc_mii_is_busy(void)
+{
+    return (u32_t) (LPC_EMAC->MIND & EMAC_MIND_BUSY);
+}
+
+/* Starts a read operation via the MII link (non-blocking) */
+u32_t lpc_mii_read_data(void)
+{
+    u32_t data = LPC_EMAC->MRDD;
+    LPC_EMAC->MCMD = 0;
+
+    return data;
+}
+
+/* Starts a read operation via the MII link (non-blocking) */
+void lpc_mii_read_noblock(u32_t PhyReg) 
+{
+    /* Read value at PHY address and register */
+    LPC_EMAC->MADR = (LPC_PHYDEF_PHYADDR << 8) | PhyReg;
+    LPC_EMAC->MCMD = EMAC_MCMD_READ;
+}
+
+/* Read a value via the MII link (blocking) */
+err_t lpc_mii_read(u32_t PhyReg, u32_t *data) 
+{
+    u32_t mst = 250;
+    err_t sts = ERR_OK;
+
+    /* Read value at PHY address and register */
+    lpc_mii_read_noblock(PhyReg);
+
+    /* Wait for unbusy status */
+    while (mst > 0) {
+        sts = LPC_EMAC->MIND & ~EMAC_MIND_MII_LINK_FAIL;
+        if ((sts & EMAC_MIND_BUSY) == 0) {
+            mst = 0;
+            *data = LPC_EMAC->MRDD;
+        } else {
+            mst--;
+            osDelay(1);
+        }
+    }
+
+    LPC_EMAC->MCMD = 0;
+
+    if (sts != 0)
+        sts = ERR_TIMEOUT;
+
+    return sts;
+}
+
+/** \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;
+
+#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];
+            p->len = (u16_t) length;
+
+            /* Free pbuf from desriptor */
+            lpc_enetif->rxb[idx] = NULL;
+            lpc_enetif->rx_free_descs++;
+
+            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);
+
+            /* Queue new buffer(s) */
+            lpc_rx_queue(lpc_enetif->netif);
+        }
+    }
+
+#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 ((((u32_t) addr >= 0x2007C000) && ((u32_t) addr < 0x20083FFF))) {
+        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;
+    struct pbuf *np;
+    u32_t dn, notdmasafe = 0;
+
+    /* 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 = (u32_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 semaphore to wakeup RX receive task.*/
+        sys_sem_signal(&lpc_enetdata.RxSem);
+    }
+    
+    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 */
+        sys_arch_sem_wait(&lpc_enetif->RxSem, 0);
+        
+        /* 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_RXDESCS; 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;
+    
+    LPC_PINCON->PINSEL2 = 0x50150105;                  /* Enable P1 Ethernet Pins. */
+    LPC_PINCON->PINSEL3 = (LPC_PINCON->PINSEL3 & ~0x0000000F) | 0x00000005;
+    
+    /* 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;
+#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 lpc_enetif_init(struct netif *netif)
+{
+    err_t err;
+
+    LWIP_ASSERT("netif != NULL", (netif != NULL));
+    
+    lpc_enetdata.netif = netif;
+
+    /* set MAC hardware address */
+    mbed_mac_address((char *)netif->hwaddr);
+    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;
+
+    /* 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 */
+    err = sys_sem_new(&lpc_enetdata.RxSem, 0);
+    LWIP_ASSERT("RxSem creation error", (err == ERR_OK));
+    sys_thread_new("receive_thread", packet_rx, netif->state, DEFAULT_THREAD_STACKSIZE, RX_PRIORITY);
+
+    /* 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;
+}
+
+/**
+ * @}
+ */
+
+/* --------------------------------- End Of File ------------------------------ */