TM4C1290NCPDT: check the internet connectivity status

//*****************************************************************************
//
// lwiplib.c - lwIP TCP/IP Library Abstraction Layer.
//
// Copyright (c) 2008-2020 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
// 
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 2.2.0.295 of the Tiva Utility Library.
//
//*****************************************************************************

//*****************************************************************************
//
// Ensure that the lwIP compile time options are included first.
//
//*****************************************************************************
#include <stdint.h>
#include <stdbool.h>
#include "utils/lwiplib.h"

//*****************************************************************************
//
// Ensure that ICMP checksum offloading is enabled; otherwise the TM4C129
// driver will not operate correctly.
//
//*****************************************************************************
#ifndef LWIP_OFFLOAD_ICMP_CHKSUM
#define LWIP_OFFLOAD_ICMP_CHKSUM 1
#endif

// CT 5/9/2022. Below two lines are commented because they were inserted during lwIP+FreeRTOS example development but not working.
//#define LWIP_NETCONN 1
//#define RTOS_FREERTOS 1

//*****************************************************************************
//
// Include lwIP high-level API code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/src/api/api_msg.c"
#include "third_party/lwip-1.4.1/src/api/err.c"
#include "third_party/lwip-1.4.1/src/api/netbuf.c"
#include "third_party/lwip-1.4.1/src/api/netdb.c"
#include "third_party/lwip-1.4.1/src/api/netifapi.c"
#include "third_party/lwip-1.4.1/src/api/sockets.c"
#include "third_party/lwip-1.4.1/src/api/tcpip.c"
#include "third_party/lwip-1.4.1/src/api/api_lib.c"


//*****************************************************************************
//
// Include the core lwIP TCP/IP stack code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/src/core/def.c"
#include "third_party/lwip-1.4.1/src/core/dhcp.c"
#include "third_party/lwip-1.4.1/src/core/dns.c"
#include "third_party/lwip-1.4.1/src/core/init.c"
#include "third_party/lwip-1.4.1/src/core/mem.c"
#include "third_party/lwip-1.4.1/src/core/memp.c"
#include "third_party/lwip-1.4.1/src/core/netif.c"
#include "third_party/lwip-1.4.1/src/core/pbuf.c"
#include "third_party/lwip-1.4.1/src/core/raw.c"
#include "third_party/lwip-1.4.1/src/core/stats.c"
#include "third_party/lwip-1.4.1/src/core/sys.c"
#include "third_party/lwip-1.4.1/src/core/tcp.c"
#include "third_party/lwip-1.4.1/src/core/tcp_in.c"
#include "third_party/lwip-1.4.1/src/core/tcp_out.c"
#include "third_party/lwip-1.4.1/src/core/timers.c"
#include "third_party/lwip-1.4.1/src/core/udp.c"

//*****************************************************************************
//
// Include the IPV4 code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/src/core/ipv4/autoip.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/icmp.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/igmp.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/inet.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/inet_chksum.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/ip.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/ip_addr.c"
#include "third_party/lwip-1.4.1/src/core/ipv4/ip_frag.c"

//*****************************************************************************
//
// Include the IPV6 code.
// Note:  Code is experimental and not ready for use.
// References are included for completeness.
//
//*****************************************************************************
#if 0
#include "third_party/lwip-1.4.1/src/core/ipv6/icmp6.c"
#include "third_party/lwip-1.4.1/src/core/ipv6/inet6.c"
#include "third_party/lwip-1.4.1/src/core/ipv6/ip6.c"
#include "third_party/lwip-1.4.1/src/core/ipv6/ip6_addr.c"
#endif

//*****************************************************************************
//
// Include the lwIP SNMP code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/src/core/snmp/asn1_dec.c"
#include "third_party/lwip-1.4.1/src/core/snmp/asn1_enc.c"
#include "third_party/lwip-1.4.1/src/core/snmp/mib2.c"
#include "third_party/lwip-1.4.1/src/core/snmp/mib_structs.c"
#include "third_party/lwip-1.4.1/src/core/snmp/msg_in.c"
#include "third_party/lwip-1.4.1/src/core/snmp/msg_out.c"

//*****************************************************************************
//
// Include the network interface code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/src/netif/etharp.c"

//*****************************************************************************
//
// Include the network interface PPP code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/src/netif/ppp/auth.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/chap.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/chpms.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/fsm.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/ipcp.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/lcp.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/magic.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/md5.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/pap.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/ppp.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/ppp_oe.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/randm.c"
#include "third_party/lwip-1.4.1/src/netif/ppp/vj.c"

//*****************************************************************************
//
// Include Tiva-specific lwIP interface/porting layer code.
//
//*****************************************************************************
#include "third_party/lwip-1.4.1/ports/tiva-tm4c129/perf.c"
#include "third_party/lwip-1.4.1/ports/tiva-tm4c129/sys_arch.c"
#include "third_party/lwip-1.4.1/ports/tiva-tm4c129/netif/tiva-tm4c129.c"

//*****************************************************************************
//
//! \addtogroup lwiplib_api
//! @{
//
//*****************************************************************************

//*****************************************************************************
//
// The lwIP Library abstration layer provides for a host callback function to
// be called periodically in the lwIP context.  This is the timer interval, in
// ms, for this periodic callback.  If the timer interval is defined to 0 (the
// default value), then no periodic host callback is performed.
//
//*****************************************************************************
#ifndef HOST_TMR_INTERVAL
#define HOST_TMR_INTERVAL       0
#else
extern void lwIPHostTimerHandler(void);
#endif

//*****************************************************************************
//
// The link detect polling interval.
//
//*****************************************************************************
#define LINK_TMR_INTERVAL       10

//*****************************************************************************
//
// Set the PHY configuration to the default (internal) option if necessary.
//
//*****************************************************************************
#ifndef EMAC_PHY_CONFIG
#define EMAC_PHY_CONFIG         (EMAC_PHY_TYPE_INTERNAL |                     \
                                 EMAC_PHY_INT_MDIX_EN |                       \
                                 EMAC_PHY_AN_100B_T_FULL_DUPLEX)
#endif

//*****************************************************************************
//
// Driverlib headers needed for this library module.
//
//*****************************************************************************
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_nvic.h"
#include "driverlib/debug.h"
#include "driverlib/emac.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#if !NO_SYS
#if RTOS_FREERTOS
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"
#endif
#if ((RTOS_FREERTOS) < 1)
    #error No RTOS is defined.  Please define an RTOS.
#endif
#if ((RTOS_FREERTOS) > 1)
    #error More than one RTOS defined.  Please define only one RTOS at a time.
#endif
#endif

//*****************************************************************************
//
// The lwIP network interface structure for the Tiva Ethernet MAC.
//
//*****************************************************************************
static struct netif g_sNetIF;

//*****************************************************************************
//
// The application's interrupt handler for hardware timer events from the MAC.
//
//*****************************************************************************
tHardwareTimerHandler g_pfnTimerHandler;

//*****************************************************************************
//
// The local time for the lwIP Library Abstraction layer, used to support the
// Host and lwIP periodic callback functions.
//
//*****************************************************************************
#if NO_SYS
uint32_t g_ui32LocalTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the TCP timer was last serviced.
//
//*****************************************************************************
#if NO_SYS
static uint32_t g_ui32TCPTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the HOST timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && HOST_TMR_INTERVAL
static uint32_t g_ui32HostTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the ARP timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && LWIP_ARP
static uint32_t g_ui32ARPTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the AutoIP timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && LWIP_AUTOIP
static uint32_t g_ui32AutoIPTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the DHCP Coarse timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && LWIP_DHCP
static uint32_t g_ui32DHCPCoarseTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the DHCP Fine timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && LWIP_DHCP
static uint32_t g_ui32DHCPFineTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the IP Reassembly timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && IP_REASSEMBLY
static uint32_t g_ui32IPReassemblyTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the IGMP timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && LWIP_IGMP
static uint32_t g_ui32IGMPTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the DNS timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && LWIP_DNS
static uint32_t g_ui32DNSTimer = 0;
#endif

//*****************************************************************************
//
// The local time when the link detect timer was last serviced.
//
//*****************************************************************************
#if NO_SYS && (LWIP_AUTOIP || LWIP_DHCP)
static uint32_t g_ui32LinkTimer = 0;
#endif

//*****************************************************************************
//
// The default IP address acquisition mode.
//
//*****************************************************************************
static uint32_t g_ui32IPMode = IPADDR_USE_STATIC;

//*****************************************************************************
//
// The most recently detected link state.
//
//*****************************************************************************
#if LWIP_AUTOIP || LWIP_DHCP
static bool g_bLinkActive = false;
#endif

//*****************************************************************************
//
// The IP address to be used.  This is used during the initialization of the
// stack and when the interface configuration is changed.
//
//*****************************************************************************
static uint32_t g_ui32IPAddr;

//*****************************************************************************
//
// The netmask to be used.  This is used during the initialization of the stack
// and when the interface configuration is changed.
//
//*****************************************************************************
static uint32_t g_ui32NetMask;

//*****************************************************************************
//
// The gateway address to be used.  This is used during the initialization of
// the stack and when the interface configuration is changed.
//
//*****************************************************************************
static uint32_t g_ui32GWAddr;

//*****************************************************************************
//
// The stack size for the interrupt task.
//
//*****************************************************************************
#if !NO_SYS
#define STACKSIZE_LWIPINTTASK   128
#endif

//*****************************************************************************
//
// The handle for the "queue" (semaphore) used to signal the interrupt task
// from the interrupt handler.
//
//*****************************************************************************
#if !NO_SYS
static xQueueHandle g_pInterrupt;
#endif

//*****************************************************************************
//
// This task handles reading packets from the Ethernet controller and supplying
// them to the TCP/IP thread.
//
//*****************************************************************************
#if !NO_SYS
static void
lwIPInterruptTask(void *pvArg)
{
    //
    // Loop forever.
    //
    while(1)
    {
        //
        // Wait until the semaphore has been signaled.
        //
        while(xQueueReceive(g_pInterrupt, &pvArg, portMAX_DELAY) != pdPASS)
        {
        }

        //
        // Processes any packets waiting to be sent or received.
        //
        tivaif_interrupt(&g_sNetIF, (uint32_t)pvArg);

        //
        // Re-enable the Ethernet interrupts.
        //
        MAP_EMACIntEnable(EMAC0_BASE, (EMAC_INT_RECEIVE | EMAC_INT_TRANSMIT |
                                       EMAC_INT_TX_STOPPED |
                                       EMAC_INT_RX_NO_BUFFER |
                                       EMAC_INT_RX_STOPPED | EMAC_INT_PHY));
    }
}
#endif

//*****************************************************************************
//
// This function performs a periodic check of the link status and responds
// appropriately if it has changed.
//
//*****************************************************************************
#if LWIP_AUTOIP || LWIP_DHCP
static void
lwIPLinkDetect(void)
{
    bool bHaveLink;
    struct ip_addr ip_addr;
    struct ip_addr net_mask;
    struct ip_addr gw_addr;

    //
    // See if there is an active link.
    //
    bHaveLink = MAP_EMACPHYRead(EMAC0_BASE, PHY_PHYS_ADDR, EPHY_BMSR) & 
                                EPHY_BMSR_LINKSTAT;

    //
    // Return without doing anything else if the link state hasn't changed.
    //
    if(bHaveLink == g_bLinkActive)
    {
        return;
    }

    //
    // Save the new link state.
    //
    g_bLinkActive = bHaveLink;

    //
    // Clear any address information from the network interface.
    //
    ip_addr.addr = 0;
    net_mask.addr = 0;
    gw_addr.addr = 0;
    netif_set_addr(&g_sNetIF, &ip_addr, &net_mask, &gw_addr);

    //
    // See if there is a link now.
    //
    if(bHaveLink)
    {
        //
        // Start DHCP, if enabled.
        //
#if LWIP_DHCP
        if(g_ui32IPMode == IPADDR_USE_DHCP)
        {
            dhcp_start(&g_sNetIF);
        }
#endif

        //
        // Start AutoIP, if enabled and DHCP is not.
        //
#if LWIP_AUTOIP
        if(g_ui32IPMode == IPADDR_USE_AUTOIP)
        {
            autoip_start(&g_sNetIF);
        }
#endif
    }
    else
    {
        //
        // Stop DHCP, if enabled.
        //
#if LWIP_DHCP
        if(g_ui32IPMode == IPADDR_USE_DHCP)
        {
            dhcp_stop(&g_sNetIF);
        }
#endif

        //
        // Stop AutoIP, if enabled and DHCP is not.
        //
#if LWIP_AUTOIP
        if(g_ui32IPMode == IPADDR_USE_AUTOIP)
        {
            autoip_stop(&g_sNetIF);
        }
#endif
    }
}
#endif

//*****************************************************************************
//
// This function services all of the lwIP periodic timers, including TCP and
// Host timers.  This should be called from the lwIP context, which may be
// the Ethernet interrupt (in the case of a non-RTOS system) or the lwIP
// thread, in the event that an RTOS is used.
//
//*****************************************************************************
#if NO_SYS
static void
lwIPServiceTimers(void)
{
    //
    // Service the host timer.
    //
#if HOST_TMR_INTERVAL
    if((g_ui32LocalTimer - g_ui32HostTimer) >= HOST_TMR_INTERVAL)
    {
        g_ui32HostTimer = g_ui32LocalTimer;
        lwIPHostTimerHandler();
    }
#endif

    //
    // Service the ARP timer.
    //
#if LWIP_ARP
    if((g_ui32LocalTimer - g_ui32ARPTimer) >= ARP_TMR_INTERVAL)
    {
        g_ui32ARPTimer = g_ui32LocalTimer;
        etharp_tmr();
    }
#endif

    //
    // Service the TCP timer.
    //
#if LWIP_TCP
    if((g_ui32LocalTimer - g_ui32TCPTimer) >= TCP_TMR_INTERVAL)
    {
        g_ui32TCPTimer = g_ui32LocalTimer;
        tcp_tmr();
    }
#endif

    //
    // Service the AutoIP timer.
    //
#if LWIP_AUTOIP
    if((g_ui32LocalTimer - g_ui32AutoIPTimer) >= AUTOIP_TMR_INTERVAL)
    {
        g_ui32AutoIPTimer = g_ui32LocalTimer;
        autoip_tmr();
    }
#endif

    //
    // Service the DCHP Coarse Timer.
    //
#if LWIP_DHCP
    if((g_ui32LocalTimer - g_ui32DHCPCoarseTimer) >= DHCP_COARSE_TIMER_MSECS)
    {
        g_ui32DHCPCoarseTimer = g_ui32LocalTimer;
        dhcp_coarse_tmr();
    }
#endif

    //
    // Service the DCHP Fine Timer.
    //
#if LWIP_DHCP
    if((g_ui32LocalTimer - g_ui32DHCPFineTimer) >= DHCP_FINE_TIMER_MSECS)
    {
        g_ui32DHCPFineTimer = g_ui32LocalTimer;
        dhcp_fine_tmr();
    }
#endif

    //
    // Service the IP Reassembly Timer
    //
#if IP_REASSEMBLY
    if((g_ui32LocalTimer - g_ui32IPReassemblyTimer) >= IP_TMR_INTERVAL)
    {
        g_ui32IPReassemblyTimer = g_ui32LocalTimer;
        ip_reass_tmr();
    }
#endif

    //
    // Service the IGMP Timer
    //
#if LWIP_IGMP
    if((g_ui32LocalTimer - g_ui32IGMPTimer) >= IGMP_TMR_INTERVAL)
    {
        g_ui32IGMPTimer = g_ui32LocalTimer;
        igmp_tmr();
    }
#endif

    //
    // Service the DNS Timer
    //
#if LWIP_DNS
    if((g_ui32LocalTimer - g_ui32DNSTimer) >= DNS_TMR_INTERVAL)
    {
        g_ui32DNSTimer = g_ui32LocalTimer;
        dns_tmr();
    }
#endif

    //
    // Service the link timer.
    //
#if LWIP_AUTOIP || LWIP_DHCP
    if((g_ui32LocalTimer - g_ui32LinkTimer) >= LINK_TMR_INTERVAL)
    {
        g_ui32LinkTimer = g_ui32LocalTimer;
        lwIPLinkDetect();
    }
#endif
}
#endif

//*****************************************************************************
//
// Handles the timeout for the host callback function timer when using a RTOS.
//
//*****************************************************************************
#if !NO_SYS && HOST_TMR_INTERVAL
static void
lwIPPrivateHostTimer(void *pvArg)
{
    //
    // Call the application-supplied host timer callback function.
    //
    lwIPHostTimerHandler();

    //
    // Re-schedule the host timer callback function timeout.
    //
    sys_timeout(HOST_TMR_INTERVAL, lwIPPrivateHostTimer, NULL);
}
#endif

//*****************************************************************************
//
// Handles the timeout for the link detect timer when using a RTOS.
//
//*****************************************************************************
#if !NO_SYS && (LWIP_AUTOIP || LWIP_DHCP)
static void
lwIPPrivateLinkTimer(void *pvArg)
{
    //
    // Perform the link detection.
    //
    lwIPLinkDetect();

    //
    // Re-schedule the link detect timer timeout.
    //
    sys_timeout(LINK_TMR_INTERVAL, lwIPPrivateLinkTimer, NULL);
}
#endif

//*****************************************************************************
//
// Completes the initialization of lwIP.  This is directly called when not
// using a RTOS and provided as a callback to the TCP/IP thread when using a
// RTOS.
//
//*****************************************************************************
static void
lwIPPrivateInit(void *pvArg)
{
    struct ip_addr ip_addr;
    struct ip_addr net_mask;
    struct ip_addr gw_addr;

    //
    // If not using a RTOS, initialize the lwIP stack.
    //
#if NO_SYS
    lwip_init();
#endif

    //
    // If using a RTOS, create a queue (to be used as a semaphore) to signal
    // the Ethernet interrupt task from the Ethernet interrupt handler.
    //
#if !NO_SYS
#if RTOS_FREERTOS
    g_pInterrupt = xQueueCreate(1, sizeof(void *));
#endif
#endif

    //
    // If using a RTOS, create the Ethernet interrupt task.
    //
#if !NO_SYS
#if RTOS_FREERTOS
    xTaskCreate(lwIPInterruptTask, (signed portCHAR *)"eth_int",
                STACKSIZE_LWIPINTTASK, 0, tskIDLE_PRIORITY + 1,
                0);
#endif
#endif

    //
    // Setup the network address values.
    //
    if(g_ui32IPMode == IPADDR_USE_STATIC)
    {
        ip_addr.addr = htonl(g_ui32IPAddr);
        net_mask.addr = htonl(g_ui32NetMask);
        gw_addr.addr = htonl(g_ui32GWAddr);
    }
    else
    {
        ip_addr.addr = 0;
        net_mask.addr = 0;
        gw_addr.addr = 0;
    }

    //
    // Create, configure and add the Ethernet controller interface with
    // default settings.  ip_input should be used to send packets directly to
    // the stack when not using a RTOS and tcpip_input should be used to send
    // packets to the TCP/IP thread's queue when using a RTOS.
    //
#if NO_SYS
    netif_add(&g_sNetIF, &ip_addr, &net_mask, &gw_addr, NULL, tivaif_init,
              ip_input);
#else
    netif_add(&g_sNetIF, &ip_addr, &net_mask, &gw_addr, NULL, tivaif_init,
              tcpip_input);
#endif
    netif_set_default(&g_sNetIF);

    //
    // Bring the interface up.
    //
    netif_set_up(&g_sNetIF);

    //
    // Setup a timeout for the host timer callback function if using a RTOS.
    //
#if !NO_SYS && HOST_TMR_INTERVAL
    sys_timeout(HOST_TMR_INTERVAL, lwIPPrivateHostTimer, NULL);
#endif

    //
    // Setup a timeout for the link detect callback function if using a RTOS.
    //
#if !NO_SYS && (LWIP_AUTOIP || LWIP_DHCP)
    sys_timeout(LINK_TMR_INTERVAL, lwIPPrivateLinkTimer, NULL);
#endif
}

//*****************************************************************************
//
//! Initializes the lwIP TCP/IP stack.
//!
//! \param ui32SysClkHz is the current system clock rate in Hz.
//! \param pui8MAC is a pointer to a six byte array containing the MAC
//! address to be used for the interface.
//! \param ui32IPAddr is the IP address to be used (static).
//! \param ui32NetMask is the network mask to be used (static).
//! \param ui32GWAddr is the Gateway address to be used (static).
//! \param ui32IPMode is the IP Address Mode.  \b IPADDR_USE_STATIC will force
//! static IP addressing to be used, \b IPADDR_USE_DHCP will force DHCP with
//! fallback to Link Local (Auto IP), while \b IPADDR_USE_AUTOIP will force
//! Link Local only.
//!
//! This function performs initialization of the lwIP TCP/IP stack for the
//! Ethernet MAC, including DHCP and/or AutoIP, as configured.
//!
//! \return None.
//
//*****************************************************************************
void
lwIPInit(uint32_t ui32SysClkHz, const uint8_t *pui8MAC, uint32_t ui32IPAddr,
         uint32_t ui32NetMask, uint32_t ui32GWAddr, uint32_t ui32IPMode)
{
    //
    // Check the parameters.
    //
#if LWIP_DHCP && LWIP_AUTOIP
    ASSERT((ui32IPMode == IPADDR_USE_STATIC) ||
           (ui32IPMode == IPADDR_USE_DHCP) ||
           (ui32IPMode == IPADDR_USE_AUTOIP));
#elif LWIP_DHCP
    ASSERT((ui32IPMode == IPADDR_USE_STATIC) ||
           (ui32IPMode == IPADDR_USE_DHCP));
#elif LWIP_AUTOIP
    ASSERT((ui32IPMode == IPADDR_USE_STATIC) ||
           (ui32IPMode == IPADDR_USE_AUTOIP));
#else
    ASSERT(ui32IPMode == IPADDR_USE_STATIC);
#endif

    //
    // Enable the ethernet peripheral.
    //
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_EMAC0);
    MAP_SysCtlPeripheralReset(SYSCTL_PERIPH_EMAC0);

    //
    // Enable the internal PHY if it's present and we're being
    // asked to use it.
    //
    if((EMAC_PHY_CONFIG & EMAC_PHY_TYPE_MASK) == EMAC_PHY_TYPE_INTERNAL)
    {
        //
        // We've been asked to configure for use with the internal
        // PHY.  Is it present?
        //
        if(MAP_SysCtlPeripheralPresent(SYSCTL_PERIPH_EPHY0))
        {
            //
            // Yes - enable and reset it.
            //
            MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_EPHY0);
            SysCtlPeripheralReset(SYSCTL_PERIPH_EPHY0);
        }
        else
        {
            //
            // Internal PHY is not present on this part so hang here.
            //
            while(1)
            {
            }
        }
    }

    //
    // Wait for the MAC to come out of reset.
    //
    while(!MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_EMAC0))
    {
    }

    //
    // Configure for use with whichever PHY the user requires.
    //
    EMACPHYConfigSet(EMAC0_BASE, EMAC_PHY_CONFIG);

    //
    // Initialize the MAC and set the DMA mode.
    //
    MAP_EMACInit(EMAC0_BASE, ui32SysClkHz,
                 EMAC_BCONFIG_MIXED_BURST | EMAC_BCONFIG_PRIORITY_FIXED,
                 4, 4, 0);

    //
    // Set MAC configuration options.
    //
    MAP_EMACConfigSet(EMAC0_BASE, (EMAC_CONFIG_FULL_DUPLEX |
                                   EMAC_CONFIG_CHECKSUM_OFFLOAD |
                                   EMAC_CONFIG_7BYTE_PREAMBLE |
                                   EMAC_CONFIG_IF_GAP_96BITS |
                                   EMAC_CONFIG_USE_MACADDR0 |
                                   EMAC_CONFIG_SA_FROM_DESCRIPTOR |
                                   EMAC_CONFIG_BO_LIMIT_1024),
                      (EMAC_MODE_RX_STORE_FORWARD |
                       EMAC_MODE_TX_STORE_FORWARD |
                       EMAC_MODE_TX_THRESHOLD_64_BYTES |
                       EMAC_MODE_RX_THRESHOLD_64_BYTES), 0);

    //
    // Program the hardware with its MAC address (for filtering).
    //
    MAP_EMACAddrSet(EMAC0_BASE, 0, (uint8_t *)pui8MAC);

    //
    // Save the network configuration for later use by the private
    // initialization.
    //
    g_ui32IPMode = ui32IPMode;
    g_ui32IPAddr = ui32IPAddr;
    g_ui32NetMask = ui32NetMask;
    g_ui32GWAddr = ui32GWAddr;

    //
    // Initialize lwIP.  The remainder of initialization is done immediately if
    // not using a RTOS and it is deferred to the TCP/IP thread's context if
    // using a RTOS.
    //
#if NO_SYS
    lwIPPrivateInit(0);
#else
    tcpip_init(lwIPPrivateInit, 0);
#endif
}

//*****************************************************************************
//
//! Registers an interrupt callback function to handle the IEEE-1588 timer.
//!
//! \param pfnTimerFunc points to a function which is called whenever the
//! Ethernet MAC reports an interrupt relating to the IEEE-1588 hardware timer.
//!
//! This function allows an application to register a handler for all
//! interrupts generated by the IEEE-1588 hardware timer in the Ethernet MAC.
//! To allow minimal latency timer handling, the callback function provided
//! will be called in interrupt context, regardless of whether or not lwIP is
//! configured to operate with an RTOS.  In an RTOS environment, the callback
//! function is responsible for ensuring that all processing it performs is
//! compatible with the low level interrupt context it is called in.
//!
//! The callback function takes two parameters.  The first is the base address
//! of the MAC reporting the timer interrupt and the second is the timer
//! interrupt status as reported by EMACTimestampIntStatus().  Note that
//! EMACTimestampIntStatus() causes the timer interrupt sources to be cleared
//! so the application should not call EMACTimestampIntStatus() within the
//! handler.
//!
//! \return None.
//
//*****************************************************************************
void
lwIPTimerCallbackRegister(tHardwareTimerHandler pfnTimerFunc)
{
    //
    // Remember the callback function address passed.
    //
    g_pfnTimerHandler = pfnTimerFunc;
}

//*****************************************************************************
//
//! Handles periodic timer events for the lwIP TCP/IP stack.
//!
//! \param ui32TimeMS is the incremental time for this periodic interrupt.
//!
//! This function will update the local timer by the value in \e ui32TimeMS.
//! If the system is configured for use without an RTOS, an Ethernet interrupt
//! will be triggered to allow the lwIP periodic timers to be serviced in the
//! Ethernet interrupt.
//!
//! \return None.
//
//*****************************************************************************
#if NO_SYS
void
lwIPTimer(uint32_t ui32TimeMS)
{
    //
    // Increment the lwIP Ethernet timer.
    //
    g_ui32LocalTimer += ui32TimeMS;

    //
    // Generate an Ethernet interrupt.  This will perform the actual work
    // of checking the lwIP timers and taking the appropriate actions.  This is
    // needed since lwIP is not re-entrant, and this allows all lwIP calls to
    // be placed inside the Ethernet interrupt handler ensuring that all calls
    // into lwIP are coming from the same context, preventing any reentrancy
    // issues.  Putting all the lwIP calls in the Ethernet interrupt handler
    // avoids the use of mutexes to avoid re-entering lwIP.
    //
    HWREG(NVIC_SW_TRIG) |= INT_EMAC0 - 16;
}
#endif

//*****************************************************************************
//
//! Handles Ethernet interrupts for the lwIP TCP/IP stack.
//!
//! This function handles Ethernet interrupts for the lwIP TCP/IP stack.  At
//! the lowest level, all receive packets are placed into a packet queue for
//! processing at a higher level.  Also, the transmit packet queue is checked
//! and packets are drained and transmitted through the Ethernet MAC as needed.
//! If the system is configured without an RTOS, additional processing is
//! performed at the interrupt level.  The packet queues are processed by the
//! lwIP TCP/IP code, and lwIP periodic timers are serviced (as needed).
//!
//! \return None.
//
//*****************************************************************************
void
lwIPEthernetIntHandler(void)
{
    uint32_t ui32Status;
    uint32_t ui32TimerStatus;
#if !NO_SYS
    portBASE_TYPE xWake;
#endif

    //
    // Read and Clear the interrupt.
    //
    ui32Status = EMACIntStatus(EMAC0_BASE, true);

#if EEE_SUPPORT
    if(ui32Status & EMAC_INT_LPI)
    {
        EMACLPIStatus(EMAC0_BASE);
    }
#endif

    //
    // If the PMT mode exit status bit is set then enable the MAC transmit
    // and receive paths, read the PMT status to clear the interrupt and
    // clear the interrupt flag.
    //
    if(ui32Status & EMAC_INT_POWER_MGMNT)
    {
        MAP_EMACTxEnable(EMAC0_BASE);
        MAP_EMACRxEnable(EMAC0_BASE);

        EMACPowerManagementStatusGet(EMAC0_BASE);

        ui32Status &= ~(EMAC_INT_POWER_MGMNT);
    }

    //
    // If the interrupt really came from the Ethernet and not our
    // timer, clear it.
    //
    if(ui32Status)
    {
        MAP_EMACIntClear(EMAC0_BASE, ui32Status);
    }

    //
    // Check to see whether a hardware timer interrupt has been reported.
    //
    if(ui32Status & EMAC_INT_TIMESTAMP)
    {
        //
        // Yes - read and clear the timestamp interrupt status.
        //
        ui32TimerStatus = EMACTimestampIntStatus(EMAC0_BASE);

        //
        // If a timer interrupt handler has been registered, call it.
        //
        if(g_pfnTimerHandler)
        {
            g_pfnTimerHandler(EMAC0_BASE, ui32TimerStatus);
        }
    }

    //
    // The handling of the interrupt is different based on the use of a RTOS.
    //
#if NO_SYS
    //
    // No RTOS is being used.  If a transmit/receive interrupt was active,
    // run the low-level interrupt handler.
    //
    if(ui32Status)
    {
        tivaif_interrupt(&g_sNetIF, ui32Status);
    }

    //
    // Service the lwIP timers.
    //
    lwIPServiceTimers();
#else
    //
    // A RTOS is being used.  Signal the Ethernet interrupt task.
    //
    xQueueSendFromISR(g_pInterrupt, (void *)&ui32Status, &xWake);

    //
    // Disable the Ethernet interrupts.  Since the interrupts have not been
    // handled, they are not asserted.  Once they are handled by the Ethernet
    // interrupt task, it will re-enable the interrupts.
    //
    MAP_EMACIntDisable(EMAC0_BASE, (EMAC_INT_RECEIVE | EMAC_INT_TRANSMIT |
                                    EMAC_INT_TX_STOPPED |
                                    EMAC_INT_RX_NO_BUFFER |
                                    EMAC_INT_RX_STOPPED | EMAC_INT_PHY));

    //
    // Potentially task switch as a result of the above queue write.
    //
#if RTOS_FREERTOS
    if(xWake == pdTRUE)
    {
        portYIELD_FROM_ISR(true);
    }
#endif
#endif
}

//*****************************************************************************
//
//! Returns the IP address for this interface.
//!
//! This function will read and return the currently assigned IP address for
//! the Stellaris Ethernet interface.
//!
//! \return Returns the assigned IP address for this interface.
//
//*****************************************************************************
uint32_t
lwIPLocalIPAddrGet(void)
{
#if LWIP_AUTOIP || LWIP_DHCP
    if(g_bLinkActive)
    {
        return((uint32_t)g_sNetIF.ip_addr.addr);
    }
    else
    {
        return(0xffffffff);
    }
#else
    return((uint32_t)g_sNetIF.ip_addr.addr);
#endif
}

//*****************************************************************************
//
//! Returns the network mask for this interface.
//!
//! This function will read and return the currently assigned network mask for
//! the Stellaris Ethernet interface.
//!
//! \return the assigned network mask for this interface.
//
//*****************************************************************************
uint32_t
lwIPLocalNetMaskGet(void)
{
    return((uint32_t)g_sNetIF.netmask.addr);
}

//*****************************************************************************
//
//! Returns the gateway address for this interface.
//!
//! This function will read and return the currently assigned gateway address
//! for the Stellaris Ethernet interface.
//!
//! \return the assigned gateway address for this interface.
//
//*****************************************************************************
uint32_t
lwIPLocalGWAddrGet(void)
{
    return((uint32_t)g_sNetIF.gw.addr);
}

//*****************************************************************************
//
//! Returns the local MAC/HW address for this interface.
//!
//! \param pui8MAC is a pointer to an array of bytes used to store the MAC
//! address.
//!
//! This function will read the currently assigned MAC address into the array
//! passed in \e pui8MAC.
//!
//! \return None.
//
//*****************************************************************************
void
lwIPLocalMACGet(uint8_t *pui8MAC)
{
    MAP_EMACAddrGet(EMAC0_BASE, 0, pui8MAC);
}

//*****************************************************************************
//
// Completes the network configuration change.  This is directly called when
// not using a RTOS and provided as a callback to the TCP/IP thread when using
// a RTOS.
//
//*****************************************************************************
static void
lwIPPrivateNetworkConfigChange(void *pvArg)
{
    uint32_t ui32IPMode;
    struct ip_addr ip_addr;
    struct ip_addr net_mask;
    struct ip_addr gw_addr;

    //
    // Get the new address mode.
    //
    ui32IPMode = (uint32_t)pvArg;

    //
    // Setup the network address values.
    //
    if(ui32IPMode == IPADDR_USE_STATIC)
    {
        ip_addr.addr = htonl(g_ui32IPAddr);
        net_mask.addr = htonl(g_ui32NetMask);
        gw_addr.addr = htonl(g_ui32GWAddr);
    }
#if LWIP_DHCP || LWIP_AUTOIP
    else
    {
        ip_addr.addr = 0;
        net_mask.addr = 0;
        gw_addr.addr = 0;
    }
#endif

    //
    // Switch on the current IP Address Aquisition mode.
    //
    switch(g_ui32IPMode)
    {
        //
        // Static IP
        //
        case IPADDR_USE_STATIC:
        {
            //
            // Set the new address parameters.  This will change the address
            // configuration in lwIP, and if necessary, will reset any links
            // that are active.  This is valid for all three modes.
            //
            netif_set_addr(&g_sNetIF, &ip_addr, &net_mask, &gw_addr);

            //
            // If we are going to DHCP mode, then start the DHCP server now.
            //
#if LWIP_DHCP
            if((ui32IPMode == IPADDR_USE_DHCP) && g_bLinkActive)
            {
                dhcp_start(&g_sNetIF);
            }
#endif

            //
            // If we are going to AutoIP mode, then start the AutoIP process
            // now.
            //
#if LWIP_AUTOIP
            if((ui32IPMode == IPADDR_USE_AUTOIP) && g_bLinkActive)
            {
                autoip_start(&g_sNetIF);
            }
#endif

            //
            // And we're done.
            //
            break;
        }

        //
        // DHCP (with AutoIP fallback).
        //
#if LWIP_DHCP
        case IPADDR_USE_DHCP:
        {
            //
            // If we are going to static IP addressing, then disable DHCP and
            // force the new static IP address.
            //
            if(ui32IPMode == IPADDR_USE_STATIC)
            {
                dhcp_stop(&g_sNetIF);
                netif_set_addr(&g_sNetIF, &ip_addr, &net_mask, &gw_addr);
            }

            //
            // If we are going to AUTO IP addressing, then disable DHCP, set
            // the default addresses, and start AutoIP.
            //
#if LWIP_AUTOIP
            else if(ui32IPMode == IPADDR_USE_AUTOIP)
            {
                dhcp_stop(&g_sNetIF);
                netif_set_addr(&g_sNetIF, &ip_addr, &net_mask, &gw_addr);
                if(g_bLinkActive)
                {
                    autoip_start(&g_sNetIF);
                }
            }
#endif
            break;
        }
#endif

        //
        // AUTOIP
        //
#if LWIP_AUTOIP
        case IPADDR_USE_AUTOIP:
        {
            //
            // If we are going to static IP addressing, then disable AutoIP and
            // force the new static IP address.
            //
            if(ui32IPMode == IPADDR_USE_STATIC)
            {
                autoip_stop(&g_sNetIF);
                netif_set_addr(&g_sNetIF, &ip_addr, &net_mask, &gw_addr);
            }

            //
            // If we are going to DHCP addressing, then disable AutoIP, set the
            // default addresses, and start dhcp.
            //
#if LWIP_DHCP
            else if(ui32IPMode == IPADDR_USE_DHCP)
            {
                autoip_stop(&g_sNetIF);
                netif_set_addr(&g_sNetIF, &ip_addr, &net_mask, &gw_addr);
                if(g_bLinkActive)
                {
                    dhcp_start(&g_sNetIF);
                }
            }
#endif
            break;
        }
#endif
    }

    //
    // Bring the interface up.
    //
    netif_set_up(&g_sNetIF);

    //
    // Save the new mode.
    //
    g_ui32IPMode = ui32IPMode;
}

//*****************************************************************************
//
//! Change the configuration of the lwIP network interface.
//!
//! \param ui32IPAddr is the new IP address to be used (static).
//! \param ui32NetMask is the new network mask to be used (static).
//! \param ui32GWAddr is the new Gateway address to be used (static).
//! \param ui32IPMode is the IP Address Mode.  \b IPADDR_USE_STATIC 0 will
//! force static IP addressing to be used, \b IPADDR_USE_DHCP will force DHCP
//! with fallback to Link Local (Auto IP), while \b IPADDR_USE_AUTOIP will
//! force Link Local only.
//!
//! This function will evaluate the new configuration data.  If necessary, the
//! interface will be brought down, reconfigured, and then brought back up
//! with the new configuration.
//!
//! \return None.
//
//*****************************************************************************
void
lwIPNetworkConfigChange(uint32_t ui32IPAddr, uint32_t ui32NetMask,
                        uint32_t ui32GWAddr, uint32_t ui32IPMode)
{
    //
    // Check the parameters.
    //
#if LWIP_DHCP && LWIP_AUTOIP
    ASSERT((ui32IPMode == IPADDR_USE_STATIC) ||
           (ui32IPMode == IPADDR_USE_DHCP) ||
           (ui32IPMode == IPADDR_USE_AUTOIP));
#elif LWIP_DHCP
    ASSERT((ui32IPMode == IPADDR_USE_STATIC) ||
           (ui32IPMode == IPADDR_USE_DHCP));
#elif LWIP_AUTOIP
    ASSERT((ui32IPMode == IPADDR_USE_STATIC) ||
           (ui32IPMode == IPADDR_USE_AUTOIP));
#else
    ASSERT(ui32IPMode == IPADDR_USE_STATIC);
#endif

    //
    // Save the network configuration for later use by the private network
    // configuration change.
    //
    g_ui32IPAddr = ui32IPAddr;
    g_ui32NetMask = ui32NetMask;
    g_ui32GWAddr = ui32GWAddr;

    //
    // Complete the network configuration change.  The remainder is done
    // immediately if not using a RTOS and it is deferred to the TCP/IP
    // thread's context if using a RTOS.
    //
#if NO_SYS
    lwIPPrivateNetworkConfigChange((void *)ui32IPMode);
#else
    tcpip_callback(lwIPPrivateNetworkConfigChange, (void *)ui32IPMode);
#endif
}

//*****************************************************************************
//
// Close the Doxygen group.
//! @}
//
//*****************************************************************************