Netwoek: Ada a parameter to netdev_register() to indicate the link protocol supported by the driver. Use this value to replace some logic commited yesterday

28 files changed, 362 insertions, 240 deletions

diff --git a/nuttx/Documentation/NuttxPortingGuide.html b/nuttx/Documentation/NuttxPortingGuide.html
index 3bfd4021f..7aebea676 100644
--- a/nuttx/Documentation/NuttxPortingGuide.html
+++ b/nuttx/Documentation/NuttxPortingGuide.html
@@ -12,7 +12,7 @@
       <h1><big><font color="#3c34ec">
         <i>NuttX RTOS Porting Guide</i>
       </font></big></h1>
-      <p>Last Updated: October 14, 2014</p>
+      <p>Last Updated: November 15, 2014</p>
     </td>
   </tr>
 </table>
@@ -4315,7 +4315,7 @@ void board_led_off(int led);
   </li>
   <li>
     <p>
-    <b><code>int netdev_register(FAR struct net_driver_s *dev);</code></b>.
+    <b><code>int netdev_register(FAR struct net_driver_s *dev, enum net_lltype_e lltype);</code></b>.
     Each Ethernet driver registers itself by calling <code>netdev_register()</code>.
     </p>
   </li>
diff --git a/nuttx/arch/arm/src/c5471/c5471_ethernet.c b/nuttx/arch/arm/src/c5471/c5471_ethernet.c
index 12a15eee7..abf608cf0 100644
--- a/nuttx/arch/arm/src/c5471/c5471_ethernet.c
+++ b/nuttx/arch/arm/src/c5471/c5471_ethernet.c
@@ -2156,7 +2156,7 @@ void up_netinitialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&g_c5471[0].c_dev);
+  (void)netdev_register(&g_c5471[0].c_dev, NET_LL_ETHERNET);
 }
 
 #endif /* CONFIG_NET */
diff --git a/nuttx/arch/arm/src/kinetis/kinetis_enet.c b/nuttx/arch/arm/src/kinetis/kinetis_enet.c
index 096d3fbd0..9042fca40 100644
--- a/nuttx/arch/arm/src/kinetis/kinetis_enet.c
+++ b/nuttx/arch/arm/src/kinetis/kinetis_enet.c
@@ -1541,7 +1541,7 @@ int kinetis_netinitialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->dev);
+  (void)netdev_register(&priv->dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/arm/src/lpc17xx/lpc17_ethernet.c b/nuttx/arch/arm/src/lpc17xx/lpc17_ethernet.c
index 46c857ed2..05108d3cf 100644
--- a/nuttx/arch/arm/src/lpc17xx/lpc17_ethernet.c
+++ b/nuttx/arch/arm/src/lpc17xx/lpc17_ethernet.c
@@ -2587,7 +2587,7 @@ static inline int lpc17_ethinitialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->lp_dev);
+  (void)netdev_register(&priv->lp_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/arm/src/sam34/sam_emac.c b/nuttx/arch/arm/src/sam34/sam_emac.c
index bb0e1ff2d..2573778a4 100644
--- a/nuttx/arch/arm/src/sam34/sam_emac.c
+++ b/nuttx/arch/arm/src/sam34/sam_emac.c
@@ -3108,7 +3108,7 @@ void up_netinitialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  ret = netdev_register(&priv->dev);
+  ret = netdev_register(&priv->dev, NET_LL_ETHERNET);
   if (ret >= 0)
     {
       return;
diff --git a/nuttx/arch/arm/src/sama5/sam_emaca.c b/nuttx/arch/arm/src/sama5/sam_emaca.c
index f7df54fd6..ecfa5a45c 100644
--- a/nuttx/arch/arm/src/sama5/sam_emaca.c
+++ b/nuttx/arch/arm/src/sama5/sam_emaca.c
@@ -3157,7 +3157,7 @@ int sam_emac_initialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  ret = netdev_register(&priv->dev);
+  ret = netdev_register(&priv->dev, NET_LL_ETHERNET);
   if (ret >= 0)
     {
       return ret;
diff --git a/nuttx/arch/arm/src/sama5/sam_emacb.c b/nuttx/arch/arm/src/sama5/sam_emacb.c
index b52144cef..a32174512 100644
--- a/nuttx/arch/arm/src/sama5/sam_emacb.c
+++ b/nuttx/arch/arm/src/sama5/sam_emacb.c
@@ -3851,7 +3851,7 @@ int sam_emac_initialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  ret = netdev_register(&priv->dev);
+  ret = netdev_register(&priv->dev, NET_LL_ETHERNET);
   if (ret >= 0)
     {
       return ret;
diff --git a/nuttx/arch/arm/src/sama5/sam_gmac.c b/nuttx/arch/arm/src/sama5/sam_gmac.c
index fb18c8953..7f112b04c 100644
--- a/nuttx/arch/arm/src/sama5/sam_gmac.c
+++ b/nuttx/arch/arm/src/sama5/sam_gmac.c
@@ -3229,7 +3229,7 @@ int sam_gmac_initialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  ret = netdev_register(&priv->dev);
+  ret = netdev_register(&priv->dev, NET_LL_ETHERNET);
   if (ret >= 0)
     {
       return ret;
diff --git a/nuttx/arch/arm/src/stm32/stm32_eth.c b/nuttx/arch/arm/src/stm32/stm32_eth.c
index 729e034f5..e72a008af 100644
--- a/nuttx/arch/arm/src/stm32/stm32_eth.c
+++ b/nuttx/arch/arm/src/stm32/stm32_eth.c
@@ -3610,7 +3610,7 @@ int stm32_ethinitialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->dev);
+  (void)netdev_register(&priv->dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/arm/src/tiva/tiva_ethernet.c b/nuttx/arch/arm/src/tiva/tiva_ethernet.c
index a235fe0c1..1fb19f882 100644
--- a/nuttx/arch/arm/src/tiva/tiva_ethernet.c
+++ b/nuttx/arch/arm/src/tiva/tiva_ethernet.c
@@ -1448,7 +1448,7 @@ static inline int tiva_ethinitialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->ld_dev);
+  (void)netdev_register(&priv->ld_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/hc/src/m9s12/m9s12_ethernet.c b/nuttx/arch/hc/src/m9s12/m9s12_ethernet.c
index 023bc922b..b179fb728 100644
--- a/nuttx/arch/hc/src/m9s12/m9s12_ethernet.c
+++ b/nuttx/arch/hc/src/m9s12/m9s12_ethernet.c
@@ -685,7 +685,7 @@ int emac_initialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->d_dev);
+  (void)netdev_register(&priv->d_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/mips/src/pic32mx/pic32mx-ethernet.c b/nuttx/arch/mips/src/pic32mx/pic32mx-ethernet.c
index eeaf3ad5c..f1633f752 100644
--- a/nuttx/arch/mips/src/pic32mx/pic32mx-ethernet.c
+++ b/nuttx/arch/mips/src/pic32mx/pic32mx-ethernet.c
@@ -3143,7 +3143,7 @@ static inline int pic32mx_ethinitialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->pd_dev);
+  (void)netdev_register(&priv->pd_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/sim/src/up_netdriver.c b/nuttx/arch/sim/src/up_netdriver.c
index c6636a045..90ff0bb3e 100644
--- a/nuttx/arch/sim/src/up_netdriver.c
+++ b/nuttx/arch/sim/src/up_netdriver.c
@@ -215,7 +215,7 @@ int netdriver_init(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&g_sim_dev);
+  (void)netdev_register(&g_sim_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/arch/z80/src/ez80/ez80_emac.c b/nuttx/arch/z80/src/ez80/ez80_emac.c
index baaa953cf..f0f1797eb 100644
--- a/nuttx/arch/z80/src/ez80/ez80_emac.c
+++ b/nuttx/arch/z80/src/ez80/ez80_emac.c
@@ -2148,7 +2148,7 @@ int up_netinitialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->dev);
+  (void)netdev_register(&priv->dev, NET_LL_ETHERNET);
   return OK;
 
 errout:
diff --git a/nuttx/configs/stm32f4discovery/netnsh/defconfig b/nuttx/configs/stm32f4discovery/netnsh/defconfig
index eb0813cbe..9adfd163e 100644
--- a/nuttx/configs/stm32f4discovery/netnsh/defconfig
+++ b/nuttx/configs/stm32f4discovery/netnsh/defconfig
@@ -76,6 +76,7 @@ CONFIG_ARCH="arm"
 # CONFIG_ARCH_CHIP_C5471 is not set
 # CONFIG_ARCH_CHIP_CALYPSO is not set
 # CONFIG_ARCH_CHIP_DM320 is not set
+# CONFIG_ARCH_CHIP_EFM32 is not set
 # CONFIG_ARCH_CHIP_IMX is not set
 # CONFIG_ARCH_CHIP_KINETIS is not set
 # CONFIG_ARCH_CHIP_KL is not set
@@ -120,7 +121,7 @@ CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y
 # CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIL is not set
 # CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW is not set
 # CONFIG_ARMV7M_TOOLCHAIN_RAISONANCE is not set
-# CONFIG_SERIAL_TERMIOS is not set
+# CONFIG_ARMV7M_ITMSYSLOG is not set
 CONFIG_SDIO_DMA=y
 CONFIG_SDIO_DMAPRIO=0x00010000
 # CONFIG_SDIO_WIDTH_D1_ONLY is not set
@@ -170,6 +171,7 @@ CONFIG_SDIO_DMAPRIO=0x00010000
 # CONFIG_ARCH_CHIP_STM32F103RC is not set
 # CONFIG_ARCH_CHIP_STM32F103RD is not set
 # CONFIG_ARCH_CHIP_STM32F103RE is not set
+# CONFIG_ARCH_CHIP_STM32F103RG is not set
 # CONFIG_ARCH_CHIP_STM32F103V8 is not set
 # CONFIG_ARCH_CHIP_STM32F103VB is not set
 # CONFIG_ARCH_CHIP_STM32F103VC is not set
@@ -192,6 +194,7 @@ CONFIG_SDIO_DMAPRIO=0x00010000
 # CONFIG_ARCH_CHIP_STM32F303VB is not set
 # CONFIG_ARCH_CHIP_STM32F303VC is not set
 # CONFIG_ARCH_CHIP_STM32F401RE is not set
+# CONFIG_ARCH_CHIP_STM32F411RE is not set
 # CONFIG_ARCH_CHIP_STM32F405RG is not set
 # CONFIG_ARCH_CHIP_STM32F405VG is not set
 # CONFIG_ARCH_CHIP_STM32F405ZG is not set
@@ -223,6 +226,7 @@ CONFIG_ARCH_CHIP_STM32F407VG=y
 # CONFIG_STM32_STM32F30XX is not set
 CONFIG_STM32_STM32F40XX=y
 # CONFIG_STM32_STM32F401 is not set
+# CONFIG_STM32_STM32F411 is not set
 # CONFIG_STM32_STM32F405 is not set
 CONFIG_STM32_STM32F407=y
 # CONFIG_STM32_STM32F427 is not set
@@ -263,6 +267,10 @@ CONFIG_STM32_HAVE_CAN1=y
 CONFIG_STM32_HAVE_CAN2=y
 CONFIG_STM32_HAVE_RNG=y
 CONFIG_STM32_HAVE_ETHMAC=y
+CONFIG_STM32_HAVE_SPI2=y
+CONFIG_STM32_HAVE_SPI3=y
+# CONFIG_STM32_HAVE_SPI4 is not set
+# CONFIG_STM32_HAVE_SPI5 is not set
 # CONFIG_STM32_ADC1 is not set
 # CONFIG_STM32_ADC2 is not set
 # CONFIG_STM32_ADC3 is not set
@@ -370,7 +378,15 @@ CONFIG_STM32_RMII=y
 CONFIG_STM32_RMII_EXTCLK=y
 
 #
-# USB Host Configuration
+# USB FS Host Configuration
+#
+
+#
+# USB HS Host Configuration
+#
+
+#
+# USB Host Debug Configuration
 #
 
 #
@@ -543,6 +559,16 @@ CONFIG_PREALLOC_MQ_MSGS=4
 CONFIG_MQ_MAXMSGSIZE=32
 
 #
+# Work Queue Support
+#
+CONFIG_SCHED_WORKQUEUE=y
+CONFIG_SCHED_HPWORK=y
+CONFIG_SCHED_HPWORKPRIORITY=192
+CONFIG_SCHED_HPWORKPERIOD=50000
+CONFIG_SCHED_HPWORKSTACKSIZE=2048
+# CONFIG_SCHED_LPWORK is not set
+
+#
 # Stack and heap information
 #
 CONFIG_IDLETHREAD_STACKSIZE=1024
@@ -657,6 +683,7 @@ CONFIG_SERIAL=y
 CONFIG_ARCH_HAVE_USART6=y
 # CONFIG_ARCH_HAVE_USART7 is not set
 # CONFIG_ARCH_HAVE_USART8 is not set
+# CONFIG_ARCH_HAVE_OTHER_UART is not set
 
 #
 # USART Configuration
@@ -664,7 +691,10 @@ CONFIG_ARCH_HAVE_USART6=y
 CONFIG_USART6_ISUART=y
 CONFIG_MCU_SERIAL=y
 CONFIG_STANDARD_SERIAL=y
+CONFIG_ARCH_HAVE_SERIAL_TERMIOS=y
+# CONFIG_SERIAL_TERMIOS is not set
 CONFIG_USART6_SERIAL_CONSOLE=y
+# CONFIG_OTHER_SERIAL_CONSOLE is not set
 # CONFIG_NO_SERIAL_CONSOLE is not set
 
 #
@@ -786,6 +816,7 @@ CONFIG_IOB_THROTTLE=8
 # Routing Table Configuration
 #
 # CONFIG_NET_ROUTE is not set
+# CONFIG_NET_MULTILINK is not set
 CONFIG_NET_ETHERNET=y
 
 #
@@ -805,6 +836,8 @@ CONFIG_NET_ETHERNET=y
 # CONFIG_DISABLE_PSEUDOFS_OPERATIONS is not set
 CONFIG_FS_READABLE=y
 CONFIG_FS_WRITABLE=y
+# CONFIG_FS_NAMED_SEMAPHORES is not set
+CONFIG_FS_MQUEUE_MPATH="/var/mqueue"
 # CONFIG_FS_RAMMAP is not set
 CONFIG_FS_FAT=y
 CONFIG_FAT_LCNAMES=y
@@ -822,8 +855,8 @@ CONFIG_FAT_MAXFNAME=32
 #
 # System Logging
 #
-
 # CONFIG_SYSLOG is not set
+# CONFIG_SYSLOG_TIMESTAMP is not set
 
 #
 # Graphics Support
@@ -844,7 +877,7 @@ CONFIG_MM_REGIONS=1
 # CONFIG_AUDIO is not set
 
 #
-# Binary Formats
+# Binary Loader
 #
 # CONFIG_BINFMT_DISABLE is not set
 # CONFIG_BINFMT_EXEPATH is not set
@@ -878,6 +911,8 @@ CONFIG_POSIX_SPAWN_PROXY_STACKSIZE=1024
 CONFIG_TASK_SPAWN_DEFAULT_STACKSIZE=2048
 # CONFIG_LIBC_STRERROR is not set
 # CONFIG_LIBC_PERROR_STDOUT is not set
+CONFIG_LIBC_TMPDIR="/tmp"
+CONFIG_LIBC_MAX_TMPFILE=32
 CONFIG_ARCH_LOWPUTC=y
 # CONFIG_LIBC_LOCALTIME is not set
 CONFIG_LIB_SENDFILE_BUFSIZE=512
@@ -887,12 +922,6 @@ CONFIG_LIB_SENDFILE_BUFSIZE=512
 #
 # Non-standard Library Support
 #
-CONFIG_SCHED_WORKQUEUE=y
-CONFIG_SCHED_HPWORK=y
-CONFIG_SCHED_HPWORKPRIORITY=192
-CONFIG_SCHED_HPWORKPERIOD=50000
-CONFIG_SCHED_HPWORKSTACKSIZE=2048
-# CONFIG_SCHED_LPWORK is not set
 # CONFIG_LIB_KBDCODEC is not set
 # CONFIG_LIB_SLCDCODEC is not set
 
@@ -986,6 +1015,7 @@ CONFIG_EXAMPLES_NSH_CXXINITIALIZE=y
 # Interpreters
 #
 # CONFIG_INTERPRETERS_FICL is not set
+# CONFIG_INTERPRETERS_BAS is not set
 # CONFIG_INTERPRETERS_PCODE is not set
 
 #
@@ -1011,6 +1041,7 @@ CONFIG_NETUTILS_TFTPC=y
 CONFIG_NETUTILS_NETLIB=y
 CONFIG_NETUTILS_WEBCLIENT=y
 CONFIG_NSH_WGET_USERAGENT="NuttX/6.xx.x (; http://www.nuttx.org/)"
+CONFIG_WEBCLIENT_TIMEOUT=10
 # CONFIG_NETUTILS_WEBSERVER is not set
 # CONFIG_NETUTILS_NTPCLIENT is not set
 # CONFIG_NETUTILS_DISCOVER is not set
diff --git a/nuttx/drivers/net/cs89x0.c b/nuttx/drivers/net/cs89x0.c
index 9e386af49..069e708cd 100644
--- a/nuttx/drivers/net/cs89x0.c
+++ b/nuttx/drivers/net/cs89x0.c
@@ -951,7 +951,7 @@ int cs89x0_initialize(FAR const cs89x0_driver_s *cs89x0, int devno)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&cs89x0->cs_dev);
+  (void)netdev_register(&cs89x0->cs_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/drivers/net/dm90x0.c b/nuttx/drivers/net/dm90x0.c
index 80885b49e..13aaa38ec 100644
--- a/nuttx/drivers/net/dm90x0.c
+++ b/nuttx/drivers/net/dm90x0.c
@@ -1803,7 +1803,7 @@ int dm9x_initialize(void)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&g_dm9x[0].dm_dev);
+  (void)netdev_register(&g_dm9x[0].dm_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/drivers/net/e1000.c b/nuttx/drivers/net/e1000.c
index eb695a466..5a1861642 100644
--- a/nuttx/drivers/net/e1000.c
+++ b/nuttx/drivers/net/e1000.c
@@ -1097,7 +1097,7 @@ static int e1000_probe(uint16_t addr, pci_id_t id)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  err = netdev_register(&dev->netdev);
+  err = netdev_register(&dev->netdev, NET_LL_ETHERNET);
   if (err)
     {
       goto err2;
diff --git a/nuttx/drivers/net/enc28j60.c b/nuttx/drivers/net/enc28j60.c
index a2ec009db..5c045f1de 100644
--- a/nuttx/drivers/net/enc28j60.c
+++ b/nuttx/drivers/net/enc28j60.c
@@ -2595,7 +2595,7 @@ int enc_initialize(FAR struct spi_dev_s *spi,
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  return netdev_register(&priv->dev);
+  return netdev_register(&priv->dev, NET_LL_ETHERNET);
 }
 
 /****************************************************************************
diff --git a/nuttx/drivers/net/encx24j600.c b/nuttx/drivers/net/encx24j600.c
index 69e683fb2..d4eb7095e 100644
--- a/nuttx/drivers/net/encx24j600.c
+++ b/nuttx/drivers/net/encx24j600.c
@@ -2859,7 +2859,7 @@ int enc_initialize(FAR struct spi_dev_s *spi,
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  return netdev_register(&priv->dev);
+  return netdev_register(&priv->dev, NET_LL_ETHERNET);
 }
 
 /****************************************************************************
diff --git a/nuttx/drivers/net/skeleton.c b/nuttx/drivers/net/skeleton.c
index ae9358f91..061e8df3d 100644
--- a/nuttx/drivers/net/skeleton.c
+++ b/nuttx/drivers/net/skeleton.c
@@ -685,7 +685,7 @@ int skel_initialize(int intf)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->sk_dev);
+  (void)netdev_register(&priv->sk_dev, NET_LL_ETHERNET);
   return OK;
 }
 
diff --git a/nuttx/drivers/net/slip.c b/nuttx/drivers/net/slip.c
index ed1b0d9d6..f1533be80 100644
--- a/nuttx/drivers/net/slip.c
+++ b/nuttx/drivers/net/slip.c
@@ -935,17 +935,6 @@ int slip_initialize(int intf, FAR const char *devname)
 #endif
   priv->dev.d_private = priv;          /* Used to recover private state from dev */
 
-#ifdef CONFIG_NET_ETHERNET
-  /* If ARP is supported, indicate that it is not required for this interface.
-   * ARP is only built of CONFIG_NET_ETHERNET is enabled which always
-   * requires ARP support.  The following can happening only there multiple
-   * network interfaces enabled (CONFIG_NET_MULTINIC) and one of the
-   * interfaces is Ethernet and another is SLIP.
-   */
-
-  priv->dev.d_flags   = IFF_NOARP;
-#endif
-
   /* Open the device */
 
   priv->fd            = open(devname, O_RDWR, 0666);
@@ -1003,7 +992,7 @@ int slip_initialize(int intf, FAR const char *devname)
 
   /* Register the device with the OS so that socket IOCTLs can be performed */
 
-  (void)netdev_register(&priv->dev);
+  (void)netdev_register(&priv->dev, NET_LL_SLIP);
 
   /* When the RX and TX tasks were created, the TTY file descriptor was
    * dup'ed for each task.  This task no longer needs the file descriptor
diff --git a/nuttx/drivers/net/vnet.c b/nuttx/drivers/net/vnet.c
index bda4c62c9..7d97d5538 100644
--- a/nuttx/drivers/net/vnet.c
+++ b/nuttx/drivers/net/vnet.c
@@ -71,7 +71,7 @@
  */
 
 #ifndef CONFIG_VNET_NINTERFACES
-# define CONFIG_VNET_NINTERFACES 1
+#  define CONFIG_VNET_NINTERFACES 1
 #endif
 
 /* TX poll deley = 1 seconds. CLK_TCK is the number of clock ticks per second */
@@ -97,13 +97,14 @@
 
 struct vnet_driver_s
 {
-    bool sk_bifup;               /* true:ifup false:ifdown */
-    WDOG_ID sk_txpoll;           /* TX poll timer */
-    //WDOG_ID sk_txtimeout;        /* TX timeout timer */
+  bool sk_bifup;               /* true:ifup false:ifdown */
+  WDOG_ID sk_txpoll;           /* TX poll timer */
+  //WDOG_ID sk_txtimeout;        /* TX timeout timer */
 
-    /* This holds the information visible to uIP/NuttX */
-    struct rgmp_vnet *vnet;
-    struct net_driver_s sk_dev;  /* Interface understood by uIP */
+  /* This holds the information visible to uIP/NuttX */
+
+  struct rgmp_vnet *vnet;
+  struct net_driver_s sk_dev;  /* Interface understood by uIP */
 };
 
 /****************************************************************************
@@ -166,35 +167,42 @@ static int vnet_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac);
 
 static int vnet_transmit(FAR struct vnet_driver_s *vnet)
 {
-    int err;
+  int err;
+
+  /* Verify that the hardware is ready to send another packet.  If we get
+   * here, then we are committed to sending a packet; Higher level logic
+   * must have assured that there is not transmission in progress.
+   */
+
+  /* Increment statistics */
 
-	/* Verify that the hardware is ready to send another packet.  If we get
-	 * here, then we are committed to sending a packet; Higher level logic
-	 * must have assured that there is not transmission in progress.
-	 */
+  /* Send the packet: address=vnet->sk_dev.d_buf, length=vnet->sk_dev.d_len */
+
+  err = vnet_xmit(vnet->vnet, (char *)vnet->sk_dev.d_buf, vnet->sk_dev.d_len);
+  if (err)
+    {
+      /* Setup the TX timeout watchdog (perhaps restarting the timer) */
 
-	/* Increment statistics */
+      //(void)wd_start(vnet->sk_txtimeout, VNET_TXTIMEOUT, vnet_txtimeout, 1, (uint32_t)vnet);
 
-	/* Send the packet: address=vnet->sk_dev.d_buf, length=vnet->sk_dev.d_len */
-    err = vnet_xmit(vnet->vnet, (char *)vnet->sk_dev.d_buf, vnet->sk_dev.d_len);
-    if (err) {
-		/* Setup the TX timeout watchdog (perhaps restarting the timer) */
-		//(void)wd_start(vnet->sk_txtimeout, VNET_TXTIMEOUT, vnet_txtimeout, 1, (uint32_t)vnet);
+      /* When vnet_xmit fail, it means TX buffer is full. Watchdog
+       * is of no use here because no TX done INT will happen. So
+       * we reset the TX buffer directly.
+       */
 
-		// When vnet_xmit fail, it means TX buffer is full. Watchdog
-		// is of no use here because no TX done INT will happen. So
-		// we reset the TX buffer directly.
 #ifdef CONFIG_DEBUG
-		cprintf("VNET: TX buffer is full\n");
+      cprintf("VNET: TX buffer is full\n");
 #endif
-		return ERROR;
+      return ERROR;
     }
-    else {
-		// this step may be unnecessary here
-		vnet_txdone(vnet);
+  else
+    {
+      /* This step may be unnecessary here */
+
+      vnet_txdone(vnet);
     }
 
-    return OK;
+  return OK;
 }
 
 /****************************************************************************
@@ -223,29 +231,32 @@ static int vnet_transmit(FAR struct vnet_driver_s *vnet)
 
 static int vnet_txpoll(struct net_driver_s *dev)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
 
-	/* If the polling resulted in data that should be sent out on the network,
-	 * the field d_len is set to a value > 0.
-	 */
+  /* If the polling resulted in data that should be sent out on the network,
+   * the field d_len is set to a value > 0.
+   */
 
-	if (vnet->sk_dev.d_len > 0)
+  if (vnet->sk_dev.d_len > 0)
     {
-		arp_out(&vnet->sk_dev);
-		vnet_transmit(vnet);
-
-		/* Check if there is room in the device to hold another packet. If not,
-		 * return a non-zero value to terminate the poll.
-		 */
-		if (vnet_is_txbuff_full(vnet->vnet))
-			return 1;
+      arp_out(&vnet->sk_dev);
+      vnet_transmit(vnet);
+
+      /* Check if there is room in the device to hold another packet. If not,
+       * return a non-zero value to terminate the poll.
+       */
+
+      if (vnet_is_txbuff_full(vnet->vnet))
+        {
+          return 1;
+        }
     }
 
-	/* If zero is returned, the polling will continue until all connections have
-	 * been examined.
-	 */
+  /* If zero is returned, the polling will continue until all connections have
+   * been examined.
+   */
 
-	return 0;
+  return 0;
 }
 
 /****************************************************************************
@@ -267,53 +278,65 @@ static int vnet_txpoll(struct net_driver_s *dev)
 
 void rtos_vnet_recv(struct rgmp_vnet *rgmp_vnet, char *data, int len)
 {
-    struct vnet_driver_s *vnet = rgmp_vnet->priv;
+  struct vnet_driver_s *vnet = rgmp_vnet->priv;
 
-    do {
-		/* Check for errors and update statistics */
+  do
+    {
+      /* Check for errors and update statistics */
+
+      /* Check if the packet is a valid size for the uIP buffer configuration */
 
-		/* Check if the packet is a valid size for the uIP buffer configuration */
-		if (len > CONFIG_NET_BUFSIZE || len < 14) {
+      if (len > CONFIG_NET_BUFSIZE || len < 14)
+        {
 #ifdef CONFIG_DEBUG
-			cprintf("VNET: receive invalid packet of size %d\n", len);
+          cprintf("VNET: receive invalid packet of size %d\n", len);
 #endif
-			return;
-		}
+          return;
+        }
+
+      /* Copy the data data from the hardware to vnet->sk_dev.d_buf.  Set
+       * amount of data in vnet->sk_dev.d_len
+       */
 
-		// Copy the data data from the hardware to vnet->sk_dev.d_buf.  Set
-		// amount of data in vnet->sk_dev.d_len
-		memcpy(vnet->sk_dev.d_buf, data, len);
-		vnet->sk_dev.d_len = len;
+      memcpy(vnet->sk_dev.d_buf, data, len);
+      vnet->sk_dev.d_len = len;
 
-		/* We only accept IP packets of the configured type and ARP packets */
+      /* We only accept IP packets of the configured type and ARP packets */
 
 #ifdef CONFIG_NET_IPv6
-		if (BUF->type == HTONS(ETHTYPE_IP6))
+      if (BUF->type == HTONS(ETHTYPE_IP6))
 #else
-			if (BUF->type == HTONS(ETHTYPE_IP))
+      if (BUF->type == HTONS(ETHTYPE_IP))
 #endif
-			{
-				arp_ipin(&vnet->sk_dev);
-				devif_input(&vnet->sk_dev);
-
-				// If the above function invocation resulted in data that should be
-				// sent out on the network, the field  d_len will set to a value > 0.
-				if (vnet->sk_dev.d_len > 0) {
-					arp_out(&vnet->sk_dev);
-					vnet_transmit(vnet);
-				}
-			}
-			else if (BUF->type == htons(ETHTYPE_ARP)) {
-				arp_arpin(&vnet->sk_dev);
-
-				// If the above function invocation resulted in data that should be
-				// sent out on the network, the field  d_len will set to a value > 0.
-				if (vnet->sk_dev.d_len > 0) {
-					vnet_transmit(vnet);
-				}
-			}
+        {
+          arp_ipin(&vnet->sk_dev);
+          devif_input(&vnet->sk_dev);
+
+          /* If the above function invocation resulted in data that should be
+           * sent out on the network, the field  d_len will set to a value > 0.
+           */
+
+          if (vnet->sk_dev.d_len > 0)
+            {
+              arp_out(&vnet->sk_dev);
+              vnet_transmit(vnet);
+            }
+        }
+      else if (BUF->type == htons(ETHTYPE_ARP))
+        {
+          arp_arpin(&vnet->sk_dev);
+
+          /* If the above function invocation resulted in data that should be
+           * sent out on the network, the field  d_len will set to a value > 0.
+           */
+
+          if (vnet->sk_dev.d_len > 0)
+            {
+              vnet_transmit(vnet);
+            }
+        }
     }
-    while (0); /* While there are more packets to be processed */
+  while (0); /* While there are more packets to be processed */
 }
 
 /****************************************************************************
@@ -335,17 +358,17 @@ void rtos_vnet_recv(struct rgmp_vnet *rgmp_vnet, char *data, int len)
 
 static void vnet_txdone(FAR struct vnet_driver_s *vnet)
 {
-	/* Check for errors and update statistics */
+  /* Check for errors and update statistics */
 
-	/* If no further xmits are pending, then cancel the TX timeout and
-	 * disable further Tx interrupts.
-	 */
+  /* If no further xmits are pending, then cancel the TX timeout and
+   * disable further Tx interrupts.
+   */
 
-	//wd_cancel(vnet->sk_txtimeout);
+  //wd_cancel(vnet->sk_txtimeout);
 
-	/* Then poll uIP for new XMIT data */
+  /* Then poll uIP for new XMIT data */
 
-	(void)devif_poll(&vnet->sk_dev, vnet_txpoll);
+  (void)devif_poll(&vnet->sk_dev, vnet_txpoll);
 }
 
 /****************************************************************************
@@ -369,15 +392,15 @@ static void vnet_txdone(FAR struct vnet_driver_s *vnet)
 
 static void vnet_txtimeout(int argc, uint32_t arg, ...)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)arg;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)arg;
 
-	/* Increment statistics and dump debug info */
+  /* Increment statistics and dump debug info */
 
-	/* Then reset the hardware */
+  /* Then reset the hardware */
 
-	/* Then poll uIP for new XMIT data */
+  /* Then poll uIP for new XMIT data */
 
-	(void)devif_poll(&vnet->sk_dev, vnet_txpoll);
+  (void)devif_poll(&vnet->sk_dev, vnet_txpoll);
 }
 
 /****************************************************************************
@@ -400,28 +423,30 @@ static void vnet_txtimeout(int argc, uint32_t arg, ...)
 
 static void vnet_polltimer(int argc, uint32_t arg, ...)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)arg;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)arg;
 
-	/* Check if there is room in the send another TX packet.  We cannot perform
-	 * the TX poll if he are unable to accept another packet for transmission.
-	 */
-	if (vnet_is_txbuff_full(vnet->vnet)) {
+  /* Check if there is room in the send another TX packet.  We cannot perform
+   * the TX poll if he are unable to accept another packet for transmission.
+   */
+
+  if (vnet_is_txbuff_full(vnet->vnet))
+    {
 #ifdef CONFIG_DEBUG
-		cprintf("VNET: TX buffer is full\n");
+      cprintf("VNET: TX buffer is full\n");
 #endif
-		return;
-	}
+      return;
+    }
 
-	/* If so, update TCP timing states and poll uIP for new XMIT data. Hmmm..
-	 * might be bug here.  Does this mean if there is a transmit in progress,
-	 * we will missing TCP time state updates?
-	 */
+  /* If so, update TCP timing states and poll uIP for new XMIT data. Hmmm..
+   * might be bug here.  Does this mean if there is a transmit in progress,
+   * we will missing TCP time state updates?
+   */
 
-	(void)devif_timer(&vnet->sk_dev, vnet_txpoll, VNET_POLLHSEC);
+  (void)devif_timer(&vnet->sk_dev, vnet_txpoll, VNET_POLLHSEC);
 
-	/* Setup the watchdog poll timer again */
+  /* Setup the watchdog poll timer again */
 
-	(void)wd_start(vnet->sk_txpoll, VNET_WDDELAY, vnet_polltimer, 1, arg);
+  (void)wd_start(vnet->sk_txpoll, VNET_WDDELAY, vnet_polltimer, 1, arg);
 }
 
 /****************************************************************************
@@ -443,20 +468,20 @@ static void vnet_polltimer(int argc, uint32_t arg, ...)
 
 static int vnet_ifup(struct net_driver_s *dev)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
 
-	ndbg("Bringing up: %d.%d.%d.%d\n",
-		 dev->d_ipaddr & 0xff, (dev->d_ipaddr >> 8) & 0xff,
-		 (dev->d_ipaddr >> 16) & 0xff, dev->d_ipaddr >> 24 );
+  ndbg("Bringing up: %d.%d.%d.%d\n",
+     dev->d_ipaddr & 0xff, (dev->d_ipaddr >> 8) & 0xff,
+     (dev->d_ipaddr >> 16) & 0xff, dev->d_ipaddr >> 24 );
 
-	/* Initialize PHYs, the Ethernet interface, and setup up Ethernet interrupts */
+  /* Initialize PHYs, the Ethernet interface, and setup up Ethernet interrupts */
 
-	/* Set and activate a timer process */
+  /* Set and activate a timer process */
 
-	(void)wd_start(vnet->sk_txpoll, VNET_WDDELAY, vnet_polltimer, 1, (uint32_t)vnet);
+  (void)wd_start(vnet->sk_txpoll, VNET_WDDELAY, vnet_polltimer, 1, (uint32_t)vnet);
 
-	vnet->sk_bifup = true;
-	return OK;
+  vnet->sk_bifup = true;
+  return OK;
 }
 
 /****************************************************************************
@@ -477,28 +502,28 @@ static int vnet_ifup(struct net_driver_s *dev)
 
 static int vnet_ifdown(struct net_driver_s *dev)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
-	irqstate_t flags;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
+  irqstate_t flags;
 
-	/* Disable the Ethernet interrupt */
+  /* Disable the Ethernet interrupt */
 
-	flags = irqsave();
+  flags = irqsave();
 
-	/* Cancel the TX poll timer and TX timeout timers */
+  /* Cancel the TX poll timer and TX timeout timers */
 
-	wd_cancel(vnet->sk_txpoll);
-	//wd_cancel(vnet->sk_txtimeout);
+  wd_cancel(vnet->sk_txpoll);
+  //wd_cancel(vnet->sk_txtimeout);
 
-	/* Put the EMAC is its reset, non-operational state.  This should be
-	 * a known configuration that will guarantee the vnet_ifup() always
-	 * successfully brings the interface back up.
-	 */
+  /* Put the EMAC is its reset, non-operational state.  This should be
+   * a known configuration that will guarantee the vnet_ifup() always
+   * successfully brings the interface back up.
+   */
 
-	/* Mark the device "down" */
+  /* Mark the device "down" */
 
-	vnet->sk_bifup = false;
-	irqrestore(flags);
-	return OK;
+  vnet->sk_bifup = false;
+  irqrestore(flags);
+  return OK;
 }
 
 /****************************************************************************
@@ -522,35 +547,37 @@ static int vnet_ifdown(struct net_driver_s *dev)
 
 static int vnet_txavail(struct net_driver_s *dev)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
-	irqstate_t flags;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
+  irqstate_t flags;
 
-	/* Disable interrupts because this function may be called from interrupt
-	 * level processing.
-	 */
+  /* Disable interrupts because this function may be called from interrupt
+   * level processing.
+   */
 
-	flags = irqsave();
+  flags = irqsave();
 
-	/* Ignore the notification if the interface is not yet up */
+  /* Ignore the notification if the interface is not yet up */
 
-	if (vnet->sk_bifup)
+  if (vnet->sk_bifup)
     {
-		/* Check if there is room in the hardware to hold another outgoing packet. */
-		if (vnet_is_txbuff_full(vnet->vnet)) {
+      /* Check if there is room in the hardware to hold another outgoing packet. */
+
+      if (vnet_is_txbuff_full(vnet->vnet))
+        {
 #ifdef CONFIG_DEBUG
-			cprintf("VNET: TX buffer is full\n");
+          cprintf("VNET: TX buffer is full\n");
 #endif
-			goto out;
-		}
+          goto out;
+        }
 
-		/* If so, then poll uIP for new XMIT data */
+      /* If so, then poll uIP for new XMIT data */
 
-		(void)devif_poll(&vnet->sk_dev, vnet_txpoll);
+      (void)devif_poll(&vnet->sk_dev, vnet_txpoll);
     }
 
 out:
-	irqrestore(flags);
-	return OK;
+  irqrestore(flags);
+  return OK;
 }
 
 /****************************************************************************
@@ -574,11 +601,11 @@ out:
 #ifdef CONFIG_NET_IGMP
 static int vnet_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
 
-	/* Add the MAC address to the hardware multicast routing table */
+  /* Add the MAC address to the hardware multicast routing table */
 
-	return OK;
+  return OK;
 }
 #endif
 
@@ -603,11 +630,11 @@ static int vnet_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 #ifdef CONFIG_NET_IGMP
 static int vnet_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 {
-	FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
+  FAR struct vnet_driver_s *vnet = (FAR struct vnet_driver_s *)dev->d_private;
 
-	/* Add the MAC address to the hardware multicast routing table */
+  /* Add the MAC address to the hardware multicast routing table */
 
-	return OK;
+  return OK;
 }
 #endif
 
@@ -634,39 +661,41 @@ static int vnet_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 
 int vnet_init(struct rgmp_vnet *vnet)
 {
-	struct vnet_driver_s *priv;
-	static int i = 0;
+  struct vnet_driver_s *priv;
+  static int i = 0;
 
-	if (i >= CONFIG_VNET_NINTERFACES)
-		return -1;
+  if (i >= CONFIG_VNET_NINTERFACES)
+    {
+      return -1;
+    }
 
-	priv = &g_vnet[i++];
+  priv = &g_vnet[i++];
 
-	/* Initialize the driver structure */
+  /* Initialize the driver structure */
 
-	memset(priv, 0, sizeof(struct vnet_driver_s));
-	priv->sk_dev.d_ifup    = vnet_ifup;     /* I/F down callback */
-	priv->sk_dev.d_ifdown  = vnet_ifdown;   /* I/F up (new IP address) callback */
-	priv->sk_dev.d_txavail = vnet_txavail;  /* New TX data callback */
+  memset(priv, 0, sizeof(struct vnet_driver_s));
+  priv->sk_dev.d_ifup    = vnet_ifup;     /* I/F down callback */
+  priv->sk_dev.d_ifdown  = vnet_ifdown;   /* I/F up (new IP address) callback */
+  priv->sk_dev.d_txavail = vnet_txavail;  /* New TX data callback */
 #ifdef CONFIG_NET_IGMP
-	priv->sk_dev.d_addmac  = vnet_addmac;   /* Add multicast MAC address */
-	priv->sk_dev.d_rmmac   = vnet_rmmac;    /* Remove multicast MAC address */
+  priv->sk_dev.d_addmac  = vnet_addmac;   /* Add multicast MAC address */
+  priv->sk_dev.d_rmmac   = vnet_rmmac;    /* Remove multicast MAC address */
 #endif
-	priv->sk_dev.d_private = (void*)priv;   /* Used to recover private state from dev */
+  priv->sk_dev.d_private = (void*)priv;   /* Used to recover private state from dev */
 
-	/* Create a watchdog for timing polling for and timing of transmisstions */
+  /* Create a watchdog for timing polling for and timing of transmisstions */
 
-	priv->sk_txpoll       = wd_create();    /* Create periodic poll timer */
-	//priv->sk_txtimeout    = wd_create();   /* Create TX timeout timer */
+  priv->sk_txpoll       = wd_create();    /* Create periodic poll timer */
+  //priv->sk_txtimeout    = wd_create();   /* Create TX timeout timer */
 
-	priv->vnet = vnet;
-	vnet->priv = priv;
+  priv->vnet = vnet;
+  vnet->priv = priv;
 
-	/* Register the device with the OS */
+  /* Register the device with the OS */
 
-	(void)netdev_register(&priv->sk_dev);
+  (void)netdev_register(&priv->sk_dev), NET_LL_ETHERNET;
 
-	return 0;
+  return 0;
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_VNET */
diff --git a/nuttx/include/nuttx/net/net.h b/nuttx/include/nuttx/net/net.h
index 23558b427..b077b7371 100644
--- a/nuttx/include/nuttx/net/net.h
+++ b/nuttx/include/nuttx/net/net.h
@@ -67,6 +67,14 @@
 /****************************************************************************
  * Public Types
  ****************************************************************************/
+/* Data link layer type */
+
+enum net_lltype_e
+{
+  NET_LL_ETHERNET = 0, /* Ethernet */
+  NET_LL_SLIP,         /* Serial Line Internet Protocol (SLIP) */
+  NET_LL_PPP           /* Point-to-Point Protocol (PPP) */
+};
 
 /* This defines a bitmap big enough for one bit for each socket option */
 
@@ -1003,7 +1011,8 @@ int net_vfcntl(int sockfd, int cmd, va_list ap);
  *   be found in subsequent network ioctl operations on the device.
  *
  * Parameters:
- *   dev - The device driver structure to register
+ *   dev    - The device driver structure to be registered.
+ *   lltype - Link level protocol used by the driver (Ethernet, SLIP, PPP, ...
  *
  * Returned Value:
  *   0:Success; negated errno on failure
@@ -1013,7 +1022,7 @@ int net_vfcntl(int sockfd, int cmd, va_list ap);
  *
  ****************************************************************************/
 
-int netdev_register(FAR struct net_driver_s *dev);
+int netdev_register(FAR struct net_driver_s *dev, enum net_lltype_e lltype);
 
 /****************************************************************************
  * Function: netdev_unregister
diff --git a/nuttx/include/nuttx/net/netdev.h b/nuttx/include/nuttx/net/netdev.h
index e71e446e1..5aeeb59be 100644
--- a/nuttx/include/nuttx/net/netdev.h
+++ b/nuttx/include/nuttx/net/netdev.h
@@ -96,17 +96,26 @@ struct net_driver_s
 
   uint8_t d_flags;
 
-  /* Ethernet device identity */
+#ifdef CONFIG_NET_MULTILINK
+  /* Multi network devices using multiple data links protocols are selected */
+
+  uint8_t d_lltype;         /* See enum net_datalink_e */
+#if 0 /* Not yet */
+  uint8_t d_llhdrlen;       /* Link layer header size */
+#endif
+#endif
 
 #ifdef CONFIG_NET_ETHERNET
+  /* Ethernet device identity */
+
   struct ether_addr d_mac;  /* Device MAC address */
 #endif
 
   /* Network identity */
 
-  net_ipaddr_t d_ipaddr;  /* Host IP address assigned to the network interface */
-  net_ipaddr_t d_draddr;  /* Default router IP address */
-  net_ipaddr_t d_netmask; /* Network subnet mask */
+  net_ipaddr_t d_ipaddr;    /* Host IP address assigned to the network interface */
+  net_ipaddr_t d_draddr;    /* Default router IP address */
+  net_ipaddr_t d_netmask;   /* Network subnet mask */
 
   /* The d_buf array is used to hold incoming and outgoing packets. The device
    * driver should place incoming data into this buffer. When sending data,
@@ -171,9 +180,9 @@ struct net_driver_s
 
   uint16_t d_sndlen;
 
+#ifdef CONFIG_NET_IGMP
   /* IGMP group list */
 
-#ifdef CONFIG_NET_IGMP
   sq_queue_t grplist;
 #endif
 
diff --git a/nuttx/net/Kconfig b/nuttx/net/Kconfig
index 85b71c576..bb4d421a5 100644
--- a/nuttx/net/Kconfig
+++ b/nuttx/net/Kconfig
@@ -114,13 +114,18 @@ config NET_MULTICAST
 	---help---
 		Outgoing multi-cast address support
 
-# Select Transport (should be a choice)
+# Select Data Link
+
+config NET_MULTILINK
+	bool
+	default n
 
 config NET_ETHERNET
 	bool
 	default y if !NET_SLIP
 	default n if NET_SLIP
 	select NETDEV_MULTINIC if NET_SLIP
+	select NET_MULTILINK if NET_SLIP
 	---help---
 		If NET_SLIP is not selected, then Ethernet will be used (there is
 		no need to define anything special in the configuration file to use
@@ -130,6 +135,7 @@ config NET_SLIP
 	bool "SLIP support"
 	default n
 	select NETDEV_MULTINIC if NET_ETHERNET
+	select NET_MULTILINK if NET_ETHERNET
 	---help---
 		Enables building of the SLIP driver. SLIP requires
 		at least one IP protocol selected and the following additional
diff --git a/nuttx/net/arp/arp_send.c b/nuttx/net/arp/arp_send.c
index 2a7694d5d..d03c6005e 100644
--- a/nuttx/net/arp/arp_send.c
+++ b/nuttx/net/arp/arp_send.c
@@ -229,17 +229,15 @@ int arp_send(in_addr_t ipaddr)
       goto errout;
     }
 
-#ifdef CONFIG_NET_SLIP
-  /* If this device does not require ARP bail out.  ARP is only built of
-   * CONFIG_NET_ETHERNET is enabled which always requires ARP support.  The
-   * following can happening only there multiple network interfaces enabled
-   * (CONFIG_NET_MULTINIC) and one of the interfaces is not Ethernet.  At
-   * present, this is possible only if one of the interfaces is SLIP.
-   *
-   * REVISIT:  This will need to be extended if PPP is ever incorporated.
+#ifdef CONFIG_NET_MULTILINK
+  /* ARP support is only built if the Ethernet data link is supported.
+   * However, if we are supporting multiple network devices and using
+   * different link level protocols then we can get here for other
+   * link protocals as well.  Continue and send the ARP request only
+   * if this device uses the Ethernet data link protocol.
    */
 
-  if (dev->d_flags & IFF_NOARP)
+  if (dev->d_lltype != NET_LL_ETHERNET)
     {
       return OK;
     }
diff --git a/nuttx/net/netdev/netdev_register.c b/nuttx/net/netdev/netdev_register.c
index dbe155cad..818a3c7d9 100644
--- a/nuttx/net/netdev/netdev_register.c
+++ b/nuttx/net/netdev/netdev_register.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/netdev/netdev_register.c
  *
- *   Copyright (C) 2007-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2012, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51,6 +51,7 @@
 #include <net/if.h>
 #include <net/ethernet.h>
 #include <nuttx/net/netdev.h>
+#include <nuttx/net/arp.h>
 
 #include "netdev/netdev.h"
 #include "igmp/igmp.h"
@@ -99,7 +100,9 @@ struct net_driver_s *g_netdevices = NULL;
  *   be found in subsequent network ioctl operations on the device.
  *
  * Parameters:
- *   dev - The device driver structure to register
+ *   dev    - The device driver structure to be registered.
+ *   lltype - Link level protocol used by the driver (Ethernet, SLIP, PPP, ...
+ *              ...
  *
  * Returned Value:
  *   0:Success; negated errno on failure
@@ -109,15 +112,62 @@ struct net_driver_s *g_netdevices = NULL;
  *
  ****************************************************************************/
 
-int netdev_register(FAR struct net_driver_s *dev)
+int netdev_register(FAR struct net_driver_s *dev, enum net_lltype_e lltype)
 {
+  int devnum;
+
   if (dev)
     {
-      int devnum;
-      netdev_semtake();
+#ifdef CONFIG_NET_MULTILINK
+      /* We are supporting multiple network devices and using different link
+       * level protocols.  Set the protocol usd by the device and the size
+       * of the link header used by this protocol.
+       */
+
+      switch (lltype)
+        {
+#ifdef CONFIG_NET_ETHERNET
+          case NET_LL_ETHERNET:  /* Ethernet */
+#if 0                            /* REVISIT: Not yet supported */
+            dev->d_llhdrlen = ETH_HDRLEN;
+#endif
+            break;
+#endif
+
+#ifdef CONFIG_NET_SLIP
+          case NET_LL_SLIP:      /* Serial Line Internet Protocol (SLIP) */
+#if 0                            /* REVISIT: Not yet supported */
+            dev->d_llhdrlen = 0;
+#endif
+            break;
+#endif
+
+#if 0                            /* REVISIT: Not yet supported */
+          case NET_LL_PPP:       /* Point-to-Point Protocol (PPP) */
+            dev->d_llhdrlen = 0;
+            break;
+#endif
+            break;
+
+            /* REVISIT:  Here we must also set the size of the link header
+             * header the precedes network layer headers.
+             */
+
+            break;
+
+          default:
+            nlldbg("ERROR: Unrecognized link type: %d\n", lltype);
+            return -EINVAL;
+        }
+
+      /* Remember the verified link type */
+
+      dev->d_lltype = (uint8_t)lltype
+#endif
 
       /* Assign a device name to the interface */
 
+      netdev_semtake();
       devnum = g_next_devnum++;
       snprintf(dev->d_ifname, IFNAMSIZ, NETDEV_FORMAT, devnum );
 
@@ -144,6 +194,7 @@ int netdev_register(FAR struct net_driver_s *dev)
 #endif
       return OK;
     }
+
   return -EINVAL;
 }