More SLIP integration

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3384 42af7a65-404d-4744-a932-0658087f49c3

30 files changed, 492 insertions, 192 deletions

diff --git a/nuttx/TODO b/nuttx/TODO
index 26b9ca98e..54ac726e4 100644
--- a/nuttx/TODO
+++ b/nuttx/TODO
@@ -1,4 +1,4 @@
-NuttX TODO List (Last updated March 8, 2011)
+NuttX TODO List (Last updated March 15, 2011)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
   (5)  Task/Scheduler (sched/)
@@ -310,15 +310,14 @@ o Network (net/, drivers/net)
 
   Description: The SLIP driver (drivers/net/slip.c) has had only the most superficial
                testing.  Issues/Notes:
-               (1) The main issue is the I haven't yet gotten a dual UART Linux
-                   configuration that supports SLIP (I need one UART for SLIP and
-                   one for the serial debug console).
-               (2) A second issue is that SLIP requires hardware handshake and
+               (1) A minor issue is that SLIP requires hardware handshake and
                    that has not been implemented in the UART drivers on most platforms.
-                   It might be possible to use a special cable to bypass the handshaking.
-                   Tiy might also try the slattach' option -L which is supposed to
-                   enable "3-wire operation."  Either action which may also result in
-                   data overrun errors).
+                   You can use the slattach' option -L which enables "3-wire
+                   operation."  NOTE: This may also result in data overrun errors.
+               (2) Current State:  The driver connects and responds to PINGs (ICMP
+                   ECHO) commands.  However, when used with the TCP stack and THTTPD,
+                   there is some condition that causes a hang.  So the SLIP driver
+                   is still not ready for prime-time.
                (3) Finally, the Linux slip driver is hard-coded to use an MTU of 296
                    so setting CONFIG_NET_BUFSIZE to a 296 is also advised.
   Status:      Open
diff --git a/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig b/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig
index e007c9218..e0b8278c1 100755
--- a/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig
@@ -522,6 +522,7 @@ CONFIG_MMCSD_HAVECARDDETECT=n
 # TCP/IP and UDP support via uIP
 # CONFIG_NET - Enable or disable all network features
 # CONFIG_NET_SLIP - Use the SLIP data link layer (L2)
+# CONFIG_NET_NOINT - uIP not called from interrupt level.
 # CONFIG_NET_MULTIBUFFER - Use multiple input/output buffers (probably no)
 # CONFIG_NET_IPv6 - Build in support for IPv6
 # CONFIG_NSOCKET_DESCRIPTORS - Maximum number of socket descriptors per task/thread.
@@ -548,6 +549,7 @@ CONFIG_MMCSD_HAVECARDDETECT=n
 #
 CONFIG_NET=y
 CONFIG_NET_SLIP=y
+CONFIG_NET_NOINTS=y
 CONFIG_NET_MULTIBUFFER=y
 CONFIG_NET_IPv6=n
 CONFIG_NSOCKET_DESCRIPTORS=16
diff --git a/nuttx/drivers/net/slip.c b/nuttx/drivers/net/slip.c
index 136e999c9..461a9035a 100644
--- a/nuttx/drivers/net/slip.c
+++ b/nuttx/drivers/net/slip.c
@@ -83,8 +83,12 @@
 #  warning "CONFIG_SCHED_WORKQUEUE must be set"
 #endif
 
+#ifndef CONFIG_NET_NOINTS
+#  warning "CONFIG_NET_NOINTS must be set"
+#endif
+
 #ifndef CONFIG_NET_MULTIBUFFER
-#  error "Requires CONFIG_NET_MULTIBUFFER"
+#  warning "CONFIG_NET_MULTIBUFFER must be set"
 #endif
 
 #ifndef CONFIG_SLIP_STACKSIZE
@@ -476,16 +480,22 @@ static int slip_uiptxpoll(struct uip_driver_s *dev)
 static void slip_txworker(FAR void *arg)
 {
   FAR struct slip_driver_s *priv = (FAR struct slip_driver_s *)arg;
+  uip_lock_t flags;
+
   DEBUGASSERT(priv != NULL);
 
-  /* Get exclusive access to uIP */
+  /* Get exclusive access to uIP (if it it is already being used slip_rxtask,
+   * then we have to wait).
+   */
 
   slip_semtake(priv);
 
-  /* Poll uIP for new XMIT data. uIP expects interrupts to be disabled. */
+  /* Poll uIP for new XMIT data. */
 
+  flags = uip_lock();
   priv->dev.d_buf = priv->txbuf;
   (void)uip_timer(&priv->dev, slip_uiptxpoll, SLIP_POLLHSEC);
+  uip_unlock(flags);
   slip_semgive(priv);
 }
 
@@ -638,6 +648,7 @@ static int slip_rxtask(int argc, char *argv[])
 {
   FAR struct slip_driver_s *priv;
   unsigned int index = *(argv[1]) - '0';
+  uip_lock_t flags;
   int ch;
 
   ndbg("index: %d\n", index);
@@ -703,6 +714,8 @@ static int slip_rxtask(int argc, char *argv[])
           slip_semtake(priv);
           priv->dev.d_buf = priv->rxbuf;
           priv->dev.d_len = priv->rxlen;
+
+          flags = uip_lock();
           uip_input(&priv->dev);
 
           /* If the above function invocation resulted in data that should
@@ -714,6 +727,7 @@ static int slip_rxtask(int argc, char *argv[])
             {
               slip_transmit(priv); 
             }
+          uip_unlock(flags);
           slip_semgive(priv);
         }
       else
@@ -750,14 +764,17 @@ static void slip_polltimer(int argc, uint32_t arg, ...)
   FAR struct slip_driver_s *priv = (FAR struct slip_driver_s *)arg;
   int ret;
 
-  /* Perform the poll on the worker thread.  We cannot access standard I/O
-   * from an interrupt handler.
+  /* Perform the poll on the worker thread (if the work structure is available).
+   * We should not access standard I/O from an interrupt handler.
    */
 
-  ret = work_queue(&priv->txwork, slip_txworker, priv, 0);
-  if (ret != OK)
+  if (priv->txwork.worker == NULL)
     {
-      ndbg("Failed to schedule work: %d\n", ret);
+      ret = work_queue(&priv->txwork, slip_txworker, priv, 0);
+      if (ret != OK)
+        {
+          ndbg("Failed to schedule work: %d\n", ret);
+        }
     }
 
   /* Setup the watchdog poll timer again */
@@ -857,9 +874,11 @@ static int slip_txavail(struct uip_driver_s *dev)
   FAR struct slip_driver_s *priv = (FAR struct slip_driver_s *)dev->d_private;
   int ret = OK;
 
-  /* Ignore the notification if the interface is not yet up */
+  /* Ignore the notification if the interface is not yet up OR if the worker
+   * action is already queued.
+   */
 
-  if (priv->bifup)
+  if (priv->bifup && priv->txwork.worker == NULL)
     {
       /* Perform a poll on the worker thread.  We cannot access standard I/O
        * from an interrupt handler.
diff --git a/nuttx/include/net/uip/uip.h b/nuttx/include/net/uip/uip.h
index a828d3f90..57407e632 100644
--- a/nuttx/include/net/uip/uip.h
+++ b/nuttx/include/net/uip/uip.h
@@ -5,7 +5,7 @@
  * are used by uIP programs as well as internal uIP structures and function
  * declarations.
  *
- *   Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * This logic was leveraged from uIP which also has a BSD-style license:
@@ -53,6 +53,11 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <queue.h>
+
+#ifdef CONFIG_NET_NOINTS
+#  include <semaphore.h>
+#endif
+
 #include <arpa/inet.h>
 
 #include <net/uip/uipopt.h>
@@ -309,6 +314,51 @@ extern void uip_initialize(void);
 
 extern void uip_setipid(uint16_t id);
 
+/* Critical section management.  The NuttX configuration setting
+ * CONFIG_NET_NOINT indicates that uIP not called from the interrupt level.
+ * If CONFIG_NET_NOINTS is defined, then these will map to semaphore
+ * controls.  Otherwise, it assumed that uIP will be called from interrupt
+ * level handling and these will map to interrupt enable/disable controls.
+ */
+
+#ifdef CONFIG_NET_NOINTS
+
+/* Semaphore based locking for non-interrupt based logic.
+ *
+ * uip_lock_t       -- Not used.  Only for compatibility
+ * uip_lockinit()   -- Initializes an underlying semaphore/mutex
+ * uip_lock()       -- Takes the semaphore().  Implements a re-entrant mutex.
+ * uip_unlock()     -- Gives the semaphore().
+ * uip_lockedwait() -- Like pthread_cond_wait(); releases the semaphore
+ *                     momemtarily to wait on another semaphore()
+ */
+
+typedef uint8_t uip_lock_t; /* Not really used */
+
+extern void uip_lockinit(void);
+extern uip_lock_t uip_lock(void);
+extern void uip_unlock(uip_lock_t flags);
+extern int uip_lockedwait(sem_t *sem);
+
+#else
+
+/* Enable/disable locking for interrupt based logic:
+ *
+ * uip_lock_t       -- The processor specific representation of interrupt state.
+ * uip_lockinit()   -- (Does not exist).
+ * uip_lock()       -- Disables interrupts.
+ * uip_unlock()     -- Conditionally restores interrupts.
+ * uip_lockedwait() -- Just wait for the semaphore.
+ */
+
+#  define uip_lock_t        irqstate_t
+#  define uip_lockinit()
+#  define uip_lock()        irqsave()
+#  define uip_unlock(f)     irqrestore(f)
+#  define uip_lockedwait(s) sem_wait(s)
+
+#endif
+
 /* uIP application functions
  *
  * Functions used by an application running of top of uIP. This includes
diff --git a/nuttx/net/accept.c b/nuttx/net/accept.c
index ec6f40706..27e5d2b0a 100644
--- a/nuttx/net/accept.c
+++ b/nuttx/net/accept.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/accept.c
  *
- *   Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -262,7 +262,7 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
 #else
   FAR struct sockaddr_in *inaddr = (struct sockaddr_in *)addr;
 #endif
-  irqstate_t save;
+  uip_lock_t save;
   int newfd;
   int err;
   int ret;
@@ -344,7 +344,7 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
    * for this listener.
    */
 
-  save = irqsave();
+  save = uip_lock();
   conn = (struct uip_conn *)psock->s_conn;
 
 #ifdef CONFIG_NET_TCPBACKLOG
@@ -366,7 +366,7 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
   else if (_SS_ISNONBLOCK(psock->s_flags))
     {
       err = EAGAIN;
-      goto errout_with_irq;
+      goto errout_with_lock;
     }
   else
 #endif
@@ -393,12 +393,12 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
       conn->accept          = accept_interrupt;
 
       /* Wait for the send to complete or an error to occur:  NOTES: (1)
-       * sem_wait will also terminate if a signal is received, (2) interrupts
-       * are disabled!  They will be re-enabled while the task sleeps and
+       * uip_lockedwait will also terminate if a signal is received, (2) interrupts
+       * may be disabled!  They will be re-enabled while the task sleeps and
        * automatically re-enabled when the task restarts.
        */
 
-      ret = sem_wait(&state.acpt_sem);
+      ret = uip_lockedwait(&state.acpt_sem);
 
       /* Make sure that no further interrupts are processed */
 
@@ -418,20 +418,20 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
       if (state.acpt_result != 0)
         {
           err = state.acpt_result;
-          goto errout_with_irq;
+          goto errout_with_lock;
         }
 
-      /* If sem_wait failed, then we were probably reawakened by a signal. In
-       * this case, sem_wait will have set errno appropriately.
+      /* If uip_lockedwait failed, then we were probably reawakened by a signal. In
+       * this case, uip_lockedwait will have set errno appropriately.
        */
 
       if (ret < 0)
         {
           err = -ret;
-          goto errout_with_irq;
+          goto errout_with_lock;
         }
     }
-  irqrestore(save);
+  uip_unlock(save);
 
   /* Initialize the socket structure and mark the socket as connected.
    * (The reference count on the new connection structure was set in the
@@ -443,8 +443,8 @@ int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
   pnewsock->s_flags |= _SF_CONNECTED;
   return newfd;
 
-errout_with_irq:
-  irqrestore(save);
+errout_with_lock:
+  uip_unlock(save);
 
 errout_with_socket:
   sockfd_release(newfd);
diff --git a/nuttx/net/connect.c b/nuttx/net/connect.c
index 6a5c2a8a2..ae4518ad0 100644
--- a/nuttx/net/connect.c
+++ b/nuttx/net/connect.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/connect.c
  *
- *   Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -325,7 +325,7 @@ static inline int tcp_connect(FAR struct socket *psock, const struct sockaddr_in
 #endif
 {
   struct tcp_connect_s state;
-  irqstate_t           flags;
+  uip_lock_t           flags;
   int                  ret = OK;
 
   /* Interrupts must be disabled through all of the following because
@@ -333,7 +333,7 @@ static inline int tcp_connect(FAR struct socket *psock, const struct sockaddr_in
    * setup.
    */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* Get the connection reference from the socket */
 
@@ -356,19 +356,19 @@ static inline int tcp_connect(FAR struct socket *psock, const struct sockaddr_in
       if (ret >= 0)
         {
           /* Wait for either the connect to complete or for an error/timeout
-           * to occur. NOTES:  (1) sem_wait will also terminate if a signal
-           * is received, (2) interrupts are disabled!  They will be re-
+           * to occur. NOTES:  (1) uip_lockedwait will also terminate if a signal
+           * is received, (2) interrupts may be disabled!  They will be re-
            * enabled while the task sleeps and automatically re-disabled
            * when the task restarts.
            */
 
-          ret = sem_wait(&state.tc_sem);
+          ret = uip_lockedwait(&state.tc_sem);
 
           /* Uninitialize the state structure */
 
           (void)sem_destroy(&state.tc_sem);
 
-          /* If sem_wait failed, recover the negated error (probably -EINTR) */
+          /* If uip_lockedwait failed, recover the negated error (probably -EINTR) */
 
           if (ret < 0)
             {
@@ -401,7 +401,7 @@ static inline int tcp_connect(FAR struct socket *psock, const struct sockaddr_in
         }
     }
 
-    irqrestore(flags);
+    uip_unlock(flags);
     return ret;
 }
 #endif /* CONFIG_NET_TCP */
diff --git a/nuttx/net/net_clone.c b/nuttx/net/net_clone.c
index 542f59050..8100e63d2 100644
--- a/nuttx/net/net_clone.c
+++ b/nuttx/net/net_clone.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/net_clone.c
  *
- *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -62,12 +62,12 @@
 
 int net_clone(FAR struct socket *psock1, FAR struct socket *psock2)
 {
-  irqstate_t flags;
+  uip_lock_t flags;
   int ret = OK;
 
   /* Parts of this operation need to be atomic */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* Duplicate the socket state */
 
@@ -110,7 +110,7 @@ int net_clone(FAR struct socket *psock1, FAR struct socket *psock2)
       ret = -EBADF;
     }
 
-  irqrestore(flags);
+  uip_unlock(flags);
   return ret;
 }
 
diff --git a/nuttx/net/net_close.c b/nuttx/net/net_close.c
index 50421cb55..ca2e2999c 100644
--- a/nuttx/net/net_close.c
+++ b/nuttx/net/net_close.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/net_close.c
  *
- *   Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -146,11 +146,11 @@ static uint16_t netclose_interrupt(struct uip_driver_s *dev, void *pvconn,
 static inline void netclose_disconnect(FAR struct socket *psock)
 {
   struct tcp_close_s state;
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Interrupts are disabled here to avoid race conditions */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* Is the TCP socket in a connected state? */
 
@@ -180,7 +180,7 @@ static inline void netclose_disconnect(FAR struct socket *psock)
 
                /* Wait for the disconnect event */
 
-               (void)sem_wait(&state.cl_sem);
+               (void)uip_lockedwait(&state.cl_sem);
 
                /* We are now disconnected */
 
@@ -190,7 +190,7 @@ static inline void netclose_disconnect(FAR struct socket *psock)
         }
     }
 
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 #endif
 
diff --git a/nuttx/net/net_poll.c b/nuttx/net/net_poll.c
index 7f24a1b7f..fa63c8d45 100644
--- a/nuttx/net/net_poll.c
+++ b/nuttx/net/net_poll.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/net_poll.c
  *
- *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -166,7 +166,7 @@ static inline int net_pollsetup(FAR struct socket *psock, struct pollfd *fds)
 {
   FAR struct uip_conn *conn = psock->s_conn;
   FAR struct uip_callback_s *cb;
-  irqstate_t flags;
+  uip_lock_t flags;
   int ret;
 
   /* Sanity check */
@@ -180,7 +180,7 @@ static inline int net_pollsetup(FAR struct socket *psock, struct pollfd *fds)
 
   /* Some of the  following must be atomic */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* Allocate a TCP/IP callback structure */
 
@@ -219,11 +219,11 @@ static inline int net_pollsetup(FAR struct socket *psock, struct pollfd *fds)
           sem_post(fds->sem);
         }
     }
-  irqrestore(flags);
+  uip_unlock(flags);
   return OK;
 
 errout_with_irq:
-  irqrestore(flags);
+  uip_unlock(flags);
   return ret;
 }
 #endif /* HAVE_NETPOLL */
@@ -247,7 +247,7 @@ static inline int net_pollteardown(FAR struct socket *psock, struct pollfd *fds)
 {
   FAR struct uip_conn *conn = psock->s_conn;
   FAR struct uip_callback_s *cb;
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Sanity check */
 
@@ -265,9 +265,9 @@ static inline int net_pollteardown(FAR struct socket *psock, struct pollfd *fds)
     {
       /* Release the callback */
 
-      flags = irqsave();
+      flags = uip_lock();
       uip_tcpcallbackfree(conn, cb);
-      irqrestore(flags);
+      uip_unlock(flags);
 
       /* Release the poll/select data slot */
 
diff --git a/nuttx/net/net_sockets.c b/nuttx/net/net_sockets.c
index 6e54c8719..dce8aa1f0 100644
--- a/nuttx/net/net_sockets.c
+++ b/nuttx/net/net_sockets.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/net_sockets.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -78,7 +78,7 @@ static void _net_semtake(FAR struct socketlist *list)
 {
   /* Take the semaphore (perhaps waiting) */
 
-  while (sem_wait(&list->sl_sem) != 0)
+  while (uip_lockedwait(&list->sl_sem) != 0)
     {
       /* The only case that an error should occr here is if
        * the wait was awakened by a signal.
@@ -149,9 +149,9 @@ int net_addreflist(FAR struct socketlist *list)
         * on semaphores.
         */
 
-       register irqstate_t flags = irqsave();
+       register uip_lock_t flags = uip_lock();
        list->sl_crefs++;
-       irqrestore(flags);
+       uip_unlock(flags);
     }
   return OK;
 }
@@ -173,9 +173,9 @@ int net_releaselist(FAR struct socketlist *list)
         * on semaphores.
         */
 
-       irqstate_t flags = irqsave();
+       uip_lock_t flags = uip_lock();
        crefs = --(list->sl_crefs);
-       irqrestore(flags);
+       uip_unlock(flags);
 
        /* If the count decrements to zero, then there is no reference
         * to the structure and it should be deallocated.  Since there
diff --git a/nuttx/net/net_vfcntl.c b/nuttx/net/net_vfcntl.c
index 3ea710425..e1f84a419 100644
--- a/nuttx/net/net_vfcntl.c
+++ b/nuttx/net/net_vfcntl.c
@@ -62,7 +62,7 @@
 int net_vfcntl(int sockfd, int cmd, va_list ap)
 {
   FAR struct socket *psock = sockfd_socket(sockfd);
-  irqstate_t flags;
+  uip_lock_t flags;
   int err = 0;
   int ret = 0;
 
@@ -76,7 +76,7 @@ int net_vfcntl(int sockfd, int cmd, va_list ap)
 
   /* Interrupts must be disabled in order to perform operations on socket structures */
 
-  flags = irqsave();
+  flags = uip_lock();
   switch (cmd)
     {
       case F_DUPFD:
@@ -219,7 +219,7 @@ int net_vfcntl(int sockfd, int cmd, va_list ap)
          break;
   }
 
-  irqrestore(flags);
+  uip_unlock(flags);
 
 errout:
   if (err != 0)
diff --git a/nuttx/net/netdev_register.c b/nuttx/net/netdev_register.c
index d9387c796..fd5656cfc 100644
--- a/nuttx/net/netdev_register.c
+++ b/nuttx/net/netdev_register.c
@@ -102,7 +102,7 @@ void netdev_semtake(void)
 {
   /* Take the semaphore (perhaps waiting) */
 
-  while (sem_wait(&g_netdev_sem) != 0)
+  while (uip_lockedwait(&g_netdev_sem) != 0)
     {
       /* The only case that an error should occr here is if
        * the wait was awakened by a signal.
diff --git a/nuttx/net/recvfrom.c b/nuttx/net/recvfrom.c
index 17e5b2775..c35937cce 100644
--- a/nuttx/net/recvfrom.c
+++ b/nuttx/net/recvfrom.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/recvfrom.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -691,7 +691,7 @@ static void recvfrom_init(FAR struct socket *psock, FAR void *buf, size_t len,
  *   Evaluate the result of the recv operations
  *
  * Parameters:
- *   result   The result of the sem_wait operation (may indicate EINTR)
+ *   result   The result of the uip_lockedwait operation (may indicate EINTR)
  *   pstate   A pointer to the state structure to be initialized
  *
  * Returned Value:
@@ -721,8 +721,8 @@ static ssize_t recvfrom_result(int result, struct recvfrom_s *pstate)
       return pstate->rf_result;
     }
 
-  /* If sem_wait failed, then we were probably reawakened by a signal. In
-   * this case, sem_wait will have set errno appropriately.
+  /* If uip_lockedwait failed, then we were probably reawakened by a signal. In
+   * this case, uip_lockedwait will have set errno appropriately.
    */
 
   if (result < 0)
@@ -765,7 +765,7 @@ static ssize_t udp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
 {
   struct uip_udp_conn *conn = (struct uip_udp_conn *)psock->s_conn;
   struct recvfrom_s    state;
-  irqstate_t           save;
+  uip_lock_t           save;
   int                  ret;
 
   /* Perform the UDP recvfrom() operation */
@@ -775,7 +775,7 @@ static ssize_t udp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
    * are ready.
    */
 
-  save = irqsave();
+  save = uip_lock();
   recvfrom_init(psock, buf, len, infrom, &state);
 
   /* Setup the UDP remote connection */
@@ -783,7 +783,7 @@ static ssize_t udp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
   ret = uip_udpconnect(conn, NULL);
   if (ret < 0)
     {
-      irqrestore(save);
+      uip_unlock(save);
       return ret;
     }
 
@@ -803,18 +803,18 @@ static ssize_t udp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
       uip_udpenable(conn);
 
       /* Wait for either the receive to complete or for an error/timeout to occur.
-       * NOTES:  (1) sem_wait will also terminate if a signal is received, (2)
+       * NOTES:  (1) uip_lockedwait will also terminate if a signal is received, (2)
        * interrupts are disabled!  They will be re-enabled while the task sleeps
        * and automatically re-enabled when the task restarts.
        */
 
-      ret = sem_wait(&state. rf_sem);
+      ret = uip_lockedwait(&state. rf_sem);
 
       /* Make sure that no further interrupts are processed */
 
       uip_udpdisable(conn);
       uip_udpcallbackfree(conn, state.rf_cb);
-      irqrestore(save);
+      uip_unlock(save);
       ret = recvfrom_result(ret, &state);
     }
   else
@@ -856,7 +856,7 @@ static ssize_t tcp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
 #endif
 {
   struct recvfrom_s       state;
-  irqstate_t              save;
+  uip_lock_t              save;
   int                     ret = OK;
 
   /* Verify that the SOCK_STREAM has been connected */
@@ -873,7 +873,7 @@ static ssize_t tcp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
    * are ready.
    */
 
-  save = irqsave();
+  save = uip_lock();
   recvfrom_init(psock, buf, len, infrom, &state);
 
 #if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0
@@ -925,12 +925,12 @@ static ssize_t tcp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
           state.rf_cb->event   = recvfrom_tcpinterrupt;
 
           /* Wait for either the receive to complete or for an error/timeout to occur.
-           * NOTES:  (1) sem_wait will also terminate if a signal is received, (2)
-           * interrupts are disabled!  They will be re-enabled while the task sleeps
+           * NOTES:  (1) uip_lockedwait will also terminate if a signal is received, (2)
+           * interrupts may be disabled!  They will be re-enabled while the task sleeps
            * and automatically re-enabled when the task restarts.
            */
 
-          ret = sem_wait(&state.rf_sem);
+          ret = uip_lockedwait(&state.rf_sem);
 
           /* Make sure that no further interrupts are processed */
 
@@ -943,7 +943,7 @@ static ssize_t tcp_recvfrom(FAR struct socket *psock, FAR void *buf, size_t len,
         }
     }
 
-  irqrestore(save);
+  uip_unlock(save);
   return ret;
 }
 #endif /* CONFIG_NET_TCP */
diff --git a/nuttx/net/send.c b/nuttx/net/send.c
index 475344c03..b1583f5b3 100644
--- a/nuttx/net/send.c
+++ b/nuttx/net/send.c
@@ -405,7 +405,7 @@ ssize_t send(int sockfd, const void *buf, size_t len, int flags)
 {
   FAR struct socket *psock = sockfd_socket(sockfd);
   struct send_s state;
-  irqstate_t save;
+  uip_lock_t save;
   int err;
   int ret = OK;
 
@@ -436,7 +436,7 @@ ssize_t send(int sockfd, const void *buf, size_t len, int flags)
    * are ready.
    */
 
-  save                = irqsave();
+  save                = uip_lock();
   memset(&state, 0, sizeof(struct send_s));
   (void)sem_init(&state. snd_sem, 0, 0); /* Doesn't really fail */
   state.snd_sock      = psock;             /* Socket descriptor to use */
@@ -478,12 +478,12 @@ ssize_t send(int sockfd, const void *buf, size_t len, int flags)
           netdev_txnotify(&conn->ripaddr);
 
           /* Wait for the send to complete or an error to occur:  NOTES: (1)
-           * sem_wait will also terminate if a signal is received, (2) interrupts
-           * are disabled!  They will be re-enabled while the task sleeps and
+           * uip_lockedwait will also terminate if a signal is received, (2) interrupts
+           * may be disabled!  They will be re-enabled while the task sleeps and
            * automatically re-enabled when the task restarts.
            */
 
-          ret = sem_wait(&state. snd_sem);
+          ret = uip_lockedwait(&state. snd_sem);
 
           /* Make sure that no further interrupts are processed */
 
@@ -492,7 +492,7 @@ ssize_t send(int sockfd, const void *buf, size_t len, int flags)
     }
 
   sem_destroy(&state. snd_sem);
-  irqrestore(save);
+  uip_unlock(save);
 
   /* Set the socket state to idle */
 
@@ -508,8 +508,8 @@ ssize_t send(int sockfd, const void *buf, size_t len, int flags)
       goto errout;
     }
 
-  /* If sem_wait failed, then we were probably reawakened by a signal. In
-   * this case, sem_wait will have set errno appropriately.
+  /* If uip_lockedwait failed, then we were probably reawakened by a signal. In
+   * this case, uip_lockedwait will have set errno appropriately.
    */
 
   if (ret < 0)
diff --git a/nuttx/net/sendto.c b/nuttx/net/sendto.c
index 89f478810..8e2bf29b2 100644
--- a/nuttx/net/sendto.c
+++ b/nuttx/net/sendto.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/sendto.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -233,7 +233,7 @@ ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
   FAR const struct sockaddr_in *into = (const struct sockaddr_in *)to;
 #endif
   struct sendto_s state;
-  irqstate_t save;
+  uip_lock_t save;
   int ret;
 #endif
   int err;
@@ -294,7 +294,7 @@ ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
    * are ready.
    */
 
-  save            = irqsave();
+  save            = uip_lock();
   memset(&state, 0, sizeof(struct sendto_s));
   sem_init(&state.st_sem, 0, 0);
   state.st_buflen = len;
@@ -306,7 +306,7 @@ ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
   ret = uip_udpconnect(conn, into);
   if (ret < 0)
     {
-      irqrestore(save);
+      uip_unlock(save);
       err = -ret;
       goto errout;
     }
@@ -329,19 +329,19 @@ ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
       netdev_txnotify(&conn->ripaddr);
 
       /* Wait for either the receive to complete or for an error/timeout to occur.
-       * NOTES:  (1) sem_wait will also terminate if a signal is received, (2)
-       * interrupts are disabled!  They will be re-enabled while the task sleeps
+       * NOTES:  (1) uip_lockedwait will also terminate if a signal is received, (2)
+       * interrupts may be disabled!  They will be re-enabled while the task sleeps
        * and automatically re-enabled when the task restarts.
        */
 
-      sem_wait(&state.st_sem);
+      uip_lockedwait(&state.st_sem);
 
       /* Make sure that no further interrupts are processed */
 
       uip_udpdisable(conn);
       uip_udpcallbackfree(conn, state.st_cb);
     }
-  irqrestore(save);
+  uip_unlock(save);
 
   sem_destroy(&state.st_sem);
 
diff --git a/nuttx/net/setsockopt.c b/nuttx/net/setsockopt.c
index 41fe2e3c3..f8de93cff 100644
--- a/nuttx/net/setsockopt.c
+++ b/nuttx/net/setsockopt.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/setsockopt.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -103,7 +103,7 @@
 int setsockopt(int sockfd, int level, int option, const void *value, socklen_t value_len)
 {
   FAR struct socket *psock;
-  irqstate_t flags;
+  uip_lock_t flags;
   int err;
 
   /* Get the underlying socket structure */
@@ -160,7 +160,7 @@ int setsockopt(int sockfd, int level, int option, const void *value, socklen_t v
            * level access to options.
            */
 
-           flags = irqsave();
+           flags = uip_lock();
 
           /* Set or clear the option bit */
 
@@ -172,6 +172,7 @@ int setsockopt(int sockfd, int level, int option, const void *value, socklen_t v
             {
               _SO_CLROPT(psock->s_options, option);
             }
+          uip_unlock(flags);
         }
         break;
 
diff --git a/nuttx/net/uip/Make.defs b/nuttx/net/uip/Make.defs
index c544765ac..8bd8d1839 100644
--- a/nuttx/net/uip/Make.defs
+++ b/nuttx/net/uip/Make.defs
@@ -43,6 +43,12 @@ ifeq ($(CONFIG_NET),y)
 UIP_CSRCS += uip_initialize.c uip_setipid.c uip_input.c uip_send.c \
 	     uip_poll.c uip_chksum.c uip_callback.c
 
+# Non-interrupt level support required?
+
+ifeq ($(CONFIG_NET_NOINTS),y)
+UIP_CSRCS += uip_lock.c
+endif
+
 # ARP supported is not provided for SLIP (Ethernet only)
 
 ifneq ($(CONFIG_NET_SLIP),y)
diff --git a/nuttx/net/uip/uip_callback.c b/nuttx/net/uip/uip_callback.c
index ad8a704b1..1270fd567 100644
--- a/nuttx/net/uip/uip_callback.c
+++ b/nuttx/net/uip/uip_callback.c
@@ -104,11 +104,11 @@ void uip_callbackinit(void)
 FAR struct uip_callback_s *uip_callbackalloc(FAR struct uip_callback_s **list)
 {
   struct uip_callback_s *ret;
-  irqstate_t save;
+  uip_lock_t save;
 
   /* Check  the head of the free list */
 
-  save = irqsave();
+  save = uip_lock();
   ret  = g_cbfreelist;
   if (ret)
     {
@@ -136,7 +136,7 @@ FAR struct uip_callback_s *uip_callbackalloc(FAR struct uip_callback_s **list)
     }
 #endif
 
-  irqrestore(save);
+  uip_unlock(save);
   return ret;
 }
 
@@ -157,13 +157,13 @@ void uip_callbackfree(FAR struct uip_callback_s *cb, FAR struct uip_callback_s *
 {
   FAR struct uip_callback_s *prev;
   FAR struct uip_callback_s *curr;
-  irqstate_t save;
+  uip_lock_t save;
 
   if (cb)
     {
       /* Find the callback structure in the connection's list */
 
-      save = irqsave();
+      save = uip_lock();
       if (list)
         {
           for (prev = NULL, curr = *list;
@@ -189,7 +189,7 @@ void uip_callbackfree(FAR struct uip_callback_s *cb, FAR struct uip_callback_s *
 
       cb->flink    = g_cbfreelist;
       g_cbfreelist = cb;
-      irqrestore(save);
+      uip_unlock(save);
     }
 }
 
@@ -210,13 +210,13 @@ uint16_t uip_callbackexecute(FAR struct uip_driver_s *dev, void *pvconn,
                              uint16_t flags, FAR struct uip_callback_s *list)
 {
   FAR struct uip_callback_s *next;
-  irqstate_t save;
+  uip_lock_t save;
 
   /* Loop for each callback in the list and while there are still events
    * set in the flags set.
    */
 
-  save = irqsave();
+  save = uip_lock();
   while (list && flags)
     {
       /* Save the pointer to the next callback in the lists.  This is done
@@ -244,7 +244,7 @@ uint16_t uip_callbackexecute(FAR struct uip_driver_s *dev, void *pvconn,
       list = next;
     }
 
-  irqrestore(save);
+  uip_unlock(save);
   return flags;
 }
 
diff --git a/nuttx/net/uip/uip_icmpping.c b/nuttx/net/uip/uip_icmpping.c
index b83b8b106..0799d1412 100644
--- a/nuttx/net/uip/uip_icmpping.c
+++ b/nuttx/net/uip/uip_icmpping.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_icmpping.c
  *
- *   Copyright (C) 2008-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -315,7 +315,7 @@ int uip_ping(uip_ipaddr_t addr, uint16_t id, uint16_t seqno,
              uint16_t datalen, int dsecs)
 {
   struct icmp_ping_s state;
-  irqstate_t save;
+  uip_lock_t save;
 
   /* Initialize the state structure */
 
@@ -328,7 +328,7 @@ int uip_ping(uip_ipaddr_t addr, uint16_t id, uint16_t seqno,
   state.png_datlen = datalen;          /* The length of data to send in the ECHO request */
   state.png_sent   = false;            /* ECHO request not yet sent */
 
-  save             = irqsave();
+  save             = uip_lock();
   state.png_time   = g_system_timer;
 
   /* Set up the callback */
@@ -346,18 +346,18 @@ int uip_ping(uip_ipaddr_t addr, uint16_t id, uint16_t seqno,
       netdev_txnotify(&state.png_addr);
 
       /* Wait for either the full round trip transfer to complete or
-       * for timeout to occur. (1) sem_wait will also terminate if a
-       * signal is received, (2) interrupts are disabled!  They will
+       * for timeout to occur. (1) uip_lockedwait will also terminate if a
+       * signal is received, (2) interrupts may be disabled!  They will
        * be re-enabled while the task sleeps and automatically
        * re-enabled when the task restarts.
        */
 
       nlldbg("Start time: 0x%08x seqno: %d\n", state.png_time, seqno);
-      sem_wait(&state.png_sem);
+      uip_lockedwait(&state.png_sem);
 
       uip_icmpcallbackfree(state.png_cb);
     }
-  irqrestore(save);
+  uip_unlock(save);
 
   /* Return the negated error number in the event of a failure, or the
    * sequence number of the ECHO reply on success.
diff --git a/nuttx/net/uip/uip_igmpgroup.c b/nuttx/net/uip/uip_igmpgroup.c
index af1ecd93e..076e990f9 100755
--- a/nuttx/net/uip/uip_igmpgroup.c
+++ b/nuttx/net/uip/uip_igmpgroup.c
@@ -219,7 +219,7 @@ FAR struct igmp_group_s *uip_grpalloc(FAR struct uip_driver_s *dev,
                                       FAR const uip_ipaddr_t *addr)

 {

   FAR struct igmp_group_s *group;

-  irqstate_t flags;

+  uip_lock_t flags;

 

   nllvdbg("addr: %08x dev: %p\n", *addr, dev);

   if (up_interrupt_context())

@@ -255,12 +255,12 @@ FAR struct igmp_group_s *uip_grpalloc(FAR struct uip_driver_s *dev,
 

       /* Interrupts must be disabled in order to modify the group list */

 

-      flags = irqsave();

+      flags = uip_lock();

 

       /* Add the group structure to the list in the device structure */

 

       sq_addfirst((FAR sq_entry_t*)group, &dev->grplist);

-      irqrestore(flags);

+      uip_unlock(flags);

     }

   return group;

 }

@@ -280,7 +280,7 @@ FAR struct igmp_group_s *uip_grpfind(FAR struct uip_driver_s *dev,
                                      FAR const uip_ipaddr_t *addr)

 {

   FAR struct igmp_group_s *group;

-  irqstate_t flags;

+  uip_lock_t flags;

 

   grplldbg("Searching for addr %08x\n", (int)*addr);

 

@@ -288,7 +288,7 @@ FAR struct igmp_group_s *uip_grpfind(FAR struct uip_driver_s *dev,
    * called from.

    */

 

-  flags = irqsave();

+  flags = uip_lock();

   for (group = (FAR struct igmp_group_s *)dev->grplist.head;

        group;

        group = group->next)

@@ -300,7 +300,7 @@ FAR struct igmp_group_s *uip_grpfind(FAR struct uip_driver_s *dev,
           break;

         }

     }

-  irqrestore(flags);

+  uip_unlock(flags);

   return group;

 }

 

@@ -343,13 +343,13 @@ FAR struct igmp_group_s *uip_grpallocfind(FAR struct uip_driver_s *dev,
 

 void uip_grpfree(FAR struct uip_driver_s *dev, FAR struct igmp_group_s *group)

 {

-  irqstate_t flags;

+  uip_lock_t flags;

 

   grplldbg("Free: %p flags: %02x\n", group, group->flags);

 

   /* Cancel the wdog */

 

-  flags = irqsave();

+  flags = uip_lock();

   wd_cancel(group->wdog);

   

   /* Remove the group structure from the group list in the device structure */

@@ -373,7 +373,7 @@ void uip_grpfree(FAR struct uip_driver_s *dev, FAR struct igmp_group_s *group)
     {

       grplldbg("Put back on free list\n");

       sq_addlast((FAR sq_entry_t*)group, &g_freelist);

-      irqrestore(flags);

+      uip_unlock(flags);

     }

   else

 #endif

@@ -382,7 +382,7 @@ void uip_grpfree(FAR struct uip_driver_s *dev, FAR struct igmp_group_s *group)
        * this function is executing within an interrupt handler.

        */

 

-      irqrestore(flags);

+      uip_unlock(flags);

       grplldbg("Call sched_free()\n");

       sched_free(group);

     }

diff --git a/nuttx/net/uip/uip_igmpleave.c b/nuttx/net/uip/uip_igmpleave.c
index 23067f70a..bbc25a830 100755
--- a/nuttx/net/uip/uip_igmpleave.c
+++ b/nuttx/net/uip/uip_igmpleave.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_igmpleave.c
  *
- *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2010-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * The NuttX implementation of IGMP was inspired by the IGMP add-on for the
@@ -130,7 +130,7 @@
 int igmp_leavegroup(struct uip_driver_s *dev, FAR const struct in_addr *grpaddr)
 {
   struct igmp_group_s *group;
-  irqstate_t flags;
+  uip_lock_t flags;
 
   DEBUGASSERT(dev && grpaddr);
 
@@ -146,11 +146,11 @@ int igmp_leavegroup(struct uip_driver_s *dev, FAR const struct in_addr *grpaddr)
        * could interfere with the Leave Group.
        */
  
-      flags = irqsave();
+      flags = uip_lock();
       wd_cancel(group->wdog);
       CLR_SCHEDMSG(group->flags);
       CLR_WAITMSG(group->flags);
-      irqrestore(flags);
+      uip_unlock(flags);
 
       IGMP_STATINCR(uip_stat.igmp.leaves);
 
diff --git a/nuttx/net/uip/uip_igmpmsg.c b/nuttx/net/uip/uip_igmpmsg.c
index d9837d04a..182d7b92d 100755
--- a/nuttx/net/uip/uip_igmpmsg.c
+++ b/nuttx/net/uip/uip_igmpmsg.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_igmpmgs.c
  *
- *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2010-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * The NuttX implementation of IGMP was inspired by the IGMP add-on for the
@@ -79,15 +79,15 @@
 
 void uip_igmpschedmsg(FAR struct igmp_group_s *group, uint8_t msgid)
 {
-  irqstate_t flags = irqsave();
+  uip_lock_t flags;
 
   /* The following should be atomic */
 
-  flags = irqsave();
+  flags = uip_lock();
   DEBUGASSERT(!IS_SCHEDMSG(group->flags));
   group->msgid = msgid;
   SET_SCHEDMSG(group->flags);
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 
 /****************************************************************************
@@ -99,17 +99,17 @@ void uip_igmpschedmsg(FAR struct igmp_group_s *group, uint8_t msgid)
  *
  * Assumptions:
  *   This function cannot be called from an interrupt handler (if you try it,
- *   sem_wait will assert).
+ *   uip_lockedwait will assert).
  *
  ****************************************************************************/
 
 void uip_igmpwaitmsg(FAR struct igmp_group_s *group, uint8_t msgid)
 {
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Schedule to send the message */
 
-  flags = irqsave();
+  flags = uip_lock();
   DEBUGASSERT(!IS_WAITMSG(group->flags));
   SET_WAITMSG(group->flags);
   uip_igmpschedmsg(group, msgid);
@@ -120,9 +120,9 @@ void uip_igmpwaitmsg(FAR struct igmp_group_s *group, uint8_t msgid)
     {
       /* Wait for the semaphore to be posted */
 
-      while (sem_wait(&group->sem) != 0)
+      while (uip_lockedwait(&group->sem) != 0)
         {
-          /* The only error that should occur from sem_wait() is if
+          /* The only error that should occur from uip_lockedwait() is if
            * the wait is awakened by a signal.
            */
  
@@ -133,7 +133,7 @@ void uip_igmpwaitmsg(FAR struct igmp_group_s *group, uint8_t msgid)
   /* The message has been sent and we are no longer waiting */
 
   CLR_WAITMSG(group->flags);
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 
 #endif /* CONFIG_NET_IGMP */
diff --git a/nuttx/net/uip/uip_igmptimer.c b/nuttx/net/uip/uip_igmptimer.c
index 2ae844341..4d454b091 100755
--- a/nuttx/net/uip/uip_igmptimer.c
+++ b/nuttx/net/uip/uip_igmptimer.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_igmptimer.c
  *
- *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2010-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * The NuttX implementation of IGMP was inspired by the IGMP add-on for the
@@ -220,14 +220,14 @@ void uip_igmpstarttimer(FAR struct igmp_group_s *group, uint8_t decisecs)
 
 bool uip_igmpcmptimer(FAR struct igmp_group_s *group, int maxticks)
 {
-  irqstate_t flags;
+  uip_lock_t flags;
   int remaining;
 
   /* Disable interrupts so that there is no race condition with the actual
    * timer expiration.
    */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* Get the timer remaining on the watchdog.  A time of <= zero means that
    * the watchdog was never started.
@@ -246,11 +246,11 @@ bool uip_igmpcmptimer(FAR struct igmp_group_s *group, int maxticks)
       /* Cancel the watchdog timer and return true */
 
       wd_cancel(group->wdog);
-      irqrestore(flags);
+      uip_unlock(flags);
       return true;
     }
 
-  irqrestore(flags);
+  uip_unlock(flags);
   return false;
 }
 
diff --git a/nuttx/net/uip/uip_initialize.c b/nuttx/net/uip/uip_initialize.c
index 08f9485a7..765a20ecd 100644
--- a/nuttx/net/uip/uip_initialize.c
+++ b/nuttx/net/uip/uip_initialize.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_initialize.c
  *
- *   Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Adapted for NuttX from logic in uIP which also has a BSD-like license:
@@ -115,6 +115,10 @@ uint8_t uip_reasstmr;
 
 void uip_initialize(void)
 {
+  /* Initialize the locking facility */
+
+  uip_lockinit();
+
   /* Initialize callback support */
 
   uip_callbackinit();
diff --git a/nuttx/net/uip/uip_listen.c b/nuttx/net/uip/uip_listen.c
index a913abc25..8052ca236 100644
--- a/nuttx/net/uip/uip_listen.c
+++ b/nuttx/net/uip/uip_listen.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_listen.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * A direct leverage of logic from uIP which also has b BSD style license
@@ -139,11 +139,11 @@ void uip_listeninit(void)
 
 int uip_unlisten(struct uip_conn *conn)
 {
-  irqstate_t flags;
+  uip_lock_t flags;
   int ndx;
   int ret = -EINVAL;
 
-  flags = irqsave();
+  flags = uip_lock();
   for (ndx = 0; ndx < CONFIG_NET_MAX_LISTENPORTS; ndx++)
     {
       if (uip_listenports[ndx] == conn)
@@ -154,7 +154,7 @@ int uip_unlisten(struct uip_conn *conn)
         }
     }
 
-  irqrestore(flags);
+  uip_unlock(flags);
   return ret;
 }
 
@@ -171,7 +171,7 @@ int uip_unlisten(struct uip_conn *conn)
 
 int uip_listen(struct uip_conn *conn)
 {
-  irqstate_t flags;
+  uip_lock_t flags;
   int ndx;
   int ret;
 
@@ -179,7 +179,7 @@ int uip_listen(struct uip_conn *conn)
    * is accessed from interrupt level as well.
    */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* First, check if there is already a socket listening on this port */
 
@@ -214,7 +214,7 @@ int uip_listen(struct uip_conn *conn)
         }
     }
 
-  irqrestore(flags);
+  uip_unlock(flags);
   return ret;
 }
 
diff --git a/nuttx/net/uip/uip_lock.c b/nuttx/net/uip/uip_lock.c
new file mode 100644
index 000000000..f11ae1c0e
--- /dev/null
+++ b/nuttx/net/uip/uip_lock.c
@@ -0,0 +1,219 @@
+/****************************************************************************
+ * net/uip/uip_lock.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <semaphore.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <net/uip/uip.h>
+
+#if defined(CONFIG_NET) && defined(CONFIG_NET_NOINTS)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define NO_HOLDER (pid_t)-1
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static sem_t        g_uipsem;
+static pid_t        g_holder  = NO_HOLDER;
+static unsigned int g_count   = 0;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_takesem
+ *
+ * Description:
+ *   Take the semaphore
+ *
+ ****************************************************************************/
+
+static void uip_takesem(void)
+{
+  while (sem_wait(&g_uipsem) != 0)
+    {
+      /* The only case that an error should occur here is if the wait was
+       * awakened by a signal.
+       */
+
+      ASSERT(errno == EINTR);
+    }
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: uip_lockinit
+ *
+ * Description:
+ *   Initialize the locking facility
+ *
+ ****************************************************************************/
+
+void uip_lockinit(void)
+{
+  sem_init(&g_uipsem, 0, 1);
+}
+
+/****************************************************************************
+ * Function: uip_lock
+ *
+ * Description:
+ *   Take the lock
+ *
+ ****************************************************************************/
+
+uip_lock_t uip_lock(void)
+{
+  pid_t me = getpid();
+
+  /* Does this thread already hold the semaphore? */
+
+  if (g_holder == me)
+    {
+      /* Yes.. just increment the reference count */
+
+      g_count++;
+    }
+  else
+    {
+      /* No.. take the semaphore (perhaps waiting) */
+
+      uip_takesem();
+
+      /* Now this thread holds the semaphore */
+
+      g_holder = me;
+      g_count  = 1;
+    }
+
+  return 0;
+}
+
+/****************************************************************************
+ * Function: uip_unlock
+ *
+ * Description:
+ *   Release the lock.
+ *
+ ****************************************************************************/
+
+void uip_unlock(uip_lock_t flags)
+{
+  DEBUGASSERT(g_holder == getpid() && g_count > 0);
+
+  /* If the count would go to zero, then release the semaphore */
+
+  if (g_count == 1)
+    {
+      /* We no longer hold the semaphored */
+
+      g_holder = NO_HOLDER;
+      g_count  = 0;
+      sem_post(&g_uipsem);
+    }
+  else
+    {
+      /* We still hold the seamphore. Just decrement the count */
+
+      g_count--;
+    }
+}
+
+/****************************************************************************
+ * Function: uip_lockedwait
+ *
+ * Description:
+ *   Atomically wait for sem while temporarilty releasing.
+ *
+ ****************************************************************************/
+
+int uip_lockedwait(sem_t *sem)
+{
+  pid_t        me = getpid();
+  unsigned int count;
+  irqstate_t   flags;
+  int          ret;
+
+  flags = irqsave(); /* No interrupts */
+  sched_lock();      /* No context switches */
+  if (g_holder == me)
+    {
+      /* Release the uIP semaphore, remembering the count */
+ 
+      count    = g_count;
+      g_holder = NO_HOLDER;
+      g_count  = 0;
+      sem_post(&g_uipsem);
+
+      /* Now take semaphore */
+
+      ret = sem_wait(sem);
+
+      /* Recover the uIP semaphore at the proper count */
+
+      uip_takesem();
+      g_holder = me;
+      g_count  = count;
+    }
+  else
+    {
+      ret = sem_wait(sem);
+    }
+
+  sched_unlock();
+  irqrestore(flags);
+  return ret;
+ }
+
+#endif /* CONFIG_NET */
diff --git a/nuttx/net/uip/uip_tcpbacklog.c b/nuttx/net/uip/uip_tcpbacklog.c
index b3cdba13a..198bbd6b5 100644
--- a/nuttx/net/uip/uip_tcpbacklog.c
+++ b/nuttx/net/uip/uip_tcpbacklog.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_tcpbacklog.c
  *
- *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -79,7 +79,7 @@ int uip_backlogcreate(FAR struct uip_conn *conn, int nblg)
 {
   FAR struct uip_backlog_s     *bls = NULL;
   FAR struct uip_blcontainer_s *blc;
-  irqstate_t flags;
+  uip_lock_t flags;
   int size;
   int offset;
   int i;
@@ -131,7 +131,7 @@ int uip_backlogcreate(FAR struct uip_conn *conn, int nblg)
 
   /* Destroy any existing backlog (shouldn't be any) */
 
-  flags = irqsave();
+  flags = uip_lock();
   uip_backlogdestroy(conn);
 
   /* Now install the backlog tear-off in the connection.  NOTE that bls may
@@ -141,7 +141,7 @@ int uip_backlogcreate(FAR struct uip_conn *conn, int nblg)
    */
 
   conn->backlog = bls;
-  irqrestore(flags);
+  uip_unlock(flags);
   return OK;
 }
 
diff --git a/nuttx/net/uip/uip_tcpconn.c b/nuttx/net/uip/uip_tcpconn.c
index 60eb16bc9..932aad2f7 100644
--- a/nuttx/net/uip/uip_tcpconn.c
+++ b/nuttx/net/uip/uip_tcpconn.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_tcpconn.c
  *
- *   Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Large parts of this file were leveraged from uIP logic:
@@ -208,14 +208,14 @@ void uip_tcpinit(void)
 struct uip_conn *uip_tcpalloc(void)
 {
   struct uip_conn *conn;
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Because this routine is called from both interrupt level and
    * and from user level, we have not option but to disable interrupts
    * while accessing g_free_tcp_connections[];
    */
 
-  flags = irqsave();
+  flags = uip_lock();
 
   /* Return the entry from the head of the free list */
 
@@ -258,7 +258,7 @@ struct uip_conn *uip_tcpalloc(void)
     }
 #endif
 
-  irqrestore(flags);
+  uip_unlock(flags);
 
   /* Mark the connection allocated */
 
@@ -284,7 +284,7 @@ void uip_tcpfree(struct uip_conn *conn)
 #if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0
   struct uip_readahead_s *readahead;
 #endif
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Because g_free_tcp_connections is accessed from user level and interrupt
    * level, code, it is necessary to keep interrupts disabled during this
@@ -292,7 +292,7 @@ void uip_tcpfree(struct uip_conn *conn)
    */
 
   DEBUGASSERT(conn->crefs == 0);
-  flags = irqsave();
+  flags = uip_lock();
 
   /* UIP_ALLOCATED means that that the connection is not in the active list
    * yet.
@@ -336,7 +336,7 @@ void uip_tcpfree(struct uip_conn *conn)
 
   conn->tcpstateflags = UIP_CLOSED;
   dq_addlast(&conn->node, &g_free_tcp_connections);
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 
 /****************************************************************************
@@ -508,14 +508,14 @@ int uip_tcpbind(struct uip_conn *conn, const struct sockaddr_in6 *addr)
 int uip_tcpbind(struct uip_conn *conn, const struct sockaddr_in *addr)
 #endif
 {
-  irqstate_t flags;
+  uip_lock_t flags;
   int port;
 
   /* Verify or select a local port */
 
-  flags = irqsave();
+  flags = uip_lock();
   port = uip_selectport(ntohs(addr->sin_port));
-  irqrestore(flags);
+  uip_unlock(flags);
 
   if (port < 0)
     {
@@ -566,7 +566,7 @@ int uip_tcpconnect(struct uip_conn *conn, const struct sockaddr_in6 *addr)
 int uip_tcpconnect(struct uip_conn *conn, const struct sockaddr_in *addr)
 #endif
 {
-  irqstate_t flags;
+  uip_lock_t flags;
   int port;
 
   /* The connection is expected to be in the UIP_ALLOCATED state.. i.e., 
@@ -583,9 +583,9 @@ int uip_tcpconnect(struct uip_conn *conn, const struct sockaddr_in *addr)
    * one now.
    */
 
-  flags = irqsave();
+  flags = uip_lock();
   port = uip_selectport(ntohs(conn->lport));
-  irqrestore(flags);
+  uip_unlock(flags);
 
   if (port < 0)
     {
@@ -626,9 +626,9 @@ int uip_tcpconnect(struct uip_conn *conn, const struct sockaddr_in *addr)
    * this operation.
    */
 
-  flags = irqsave();
+  flags = uip_lock();
   dq_addlast(&conn->node, &g_active_tcp_connections);
-  irqrestore(flags);
+  uip_unlock(flags);
 
   return OK;
 }
diff --git a/nuttx/net/uip/uip_udpconn.c b/nuttx/net/uip/uip_udpconn.c
index b01d58f43..0180a9c14 100644
--- a/nuttx/net/uip/uip_udpconn.c
+++ b/nuttx/net/uip/uip_udpconn.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/uip/uip_udpconn.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Large parts of this file were leveraged from uIP logic:
@@ -99,9 +99,9 @@ static inline void _uip_semtake(sem_t *sem)
 {
   /* Take the semaphore (perhaps waiting) */
 
-  while (sem_wait(sem) != 0)
+  while (uip_lockedwait(sem) != 0)
     {
-      /* The only case that an error should occr here is if
+      /* The only case that an error should occur here is if
        * the wait was awakened by a signal.
        */
 
@@ -165,7 +165,7 @@ static uint16_t uip_selectport(void)
    * listen port number that is not being used by any other connection.
    */
 
-  irqstate_t flags = irqsave();
+  uip_lock_t flags = uip_lock();
   do
     {
       /* Guess that the next available port number will be the one after
@@ -188,7 +188,7 @@ static uint16_t uip_selectport(void)
    */
 
   portno = g_last_udp_port;
-  irqrestore(flags);
+  uip_unlock(flags);
 
   return portno;
 }
@@ -367,7 +367,7 @@ int uip_udpbind(struct uip_udp_conn *conn, const struct sockaddr_in *addr)
 #endif
 {
   int ret = -EADDRINUSE;
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Is the user requesting to bind to any port? */
 
@@ -382,7 +382,7 @@ int uip_udpbind(struct uip_udp_conn *conn, const struct sockaddr_in *addr)
     {
       /* Interrupts must be disabled while access the UDP connection list */
 
-      flags = irqsave();
+      flags = uip_lock();
 
       /* Is any other UDP connection bound to this port? */
 
@@ -394,7 +394,7 @@ int uip_udpbind(struct uip_udp_conn *conn, const struct sockaddr_in *addr)
           ret         = OK;
         }
 
-      irqrestore(flags);
+      uip_unlock(flags);
     }
   return ret;
 }
@@ -471,9 +471,9 @@ void uip_udpenable(struct uip_udp_conn *conn)
    * access it safely.
    */
 
-  irqstate_t flags = irqsave();
+  uip_lock_t flags = uip_lock();
   dq_addlast(&conn->node, &g_active_udp_connections);
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 
 void uip_udpdisable(struct uip_udp_conn *conn)
@@ -483,9 +483,9 @@ void uip_udpdisable(struct uip_udp_conn *conn)
    * access it safely.
    */
 
-  irqstate_t flags = irqsave();
+  uip_lock_t flags = uip_lock();
   dq_rem(&conn->node, &g_active_udp_connections);
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_UDP */
diff --git a/nuttx/netutils/dhcpd/dhcpd.c b/nuttx/netutils/dhcpd/dhcpd.c
index cbe6c8883..0e498541c 100644
--- a/nuttx/netutils/dhcpd/dhcpd.c
+++ b/nuttx/netutils/dhcpd/dhcpd.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * netutils/dhcpd/dhcpd.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -270,15 +270,15 @@ static struct dhcpd_state_s g_state;
 #ifndef CONFIG_NETUTILS_DHCPD_HOST
 static inline void dhcpd_arpupdate(uint16_t *pipaddr, uint8_t *phwaddr)
 {
-  irqstate_t flags;
+  uip_lock_t flags;
 
   /* Disable interrupts and update the ARP table -- very non-portable hack.
    * REVISIT -- switch to the SIOCSARP ioctl call if/when it is implemented.
    */
 
-  flags = irqsave();
+  flags = uip_lock();
   uip_arp_update(pipaddr, phwaddr);
-  irqrestore(flags);
+  uip_unlock(flags);
 }
 #else
 #  define dhcpd_arpupdate(pipaddr,phwaddr)