Merge branch 'NuttX/master' from git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5027 7fd9a85b-ad96-42d3-883c-3090e2eb8679

45 files changed, 625 insertions, 248 deletions

diff --git a/apps/ChangeLog.txt b/apps/ChangeLog.txt
index 1bb2a08b5..01ef090a0 100755
--- a/apps/ChangeLog.txt
+++ b/apps/ChangeLog.txt
@@ -274,3 +274,7 @@
 	  no arguments outputs a short list of commands.  With -v lists all
 	  command line details.  And command name can be added to just get
 	  help on one command.
+	* system/readline.c:  If character input/output is interrupted by a
+	  signal, then readline() will try the read/write again.
+	* apps/*/Make.defs:  Numerous fixes needed to use the automated
+	  configuration (from Richard Cochran).
diff --git a/apps/interpreters/Make.defs b/apps/interpreters/Make.defs
index 36ee7004d..2fc4b26d4 100644
--- a/apps/interpreters/Make.defs
+++ b/apps/interpreters/Make.defs
@@ -34,10 +34,10 @@
 #
 ############################################################################
 
-if ($(CONFIG_PCODE),y)
+ifeq ($(CONFIG_PCODE),y)
 CONFIGURED_APPS += interpreters/pcode
 endif
 
-if ($(CONFIG_FICL),y)
+ifeq ($(CONFIG_FICL),y)
 CONFIGURED_APPS += interpreters/ficl
 endif
diff --git a/apps/namedapp/Make.defs b/apps/namedapp/Make.defs
index a07b3b3c2..399fefee8 100644
--- a/apps/namedapp/Make.defs
+++ b/apps/namedapp/Make.defs
@@ -34,7 +34,7 @@
 #
 ############################################################################
 
-if ($(CONFIG_NAMEDAPP),y)
+ifeq ($(CONFIG_NAMEDAPP),y)
 CONFIGURED_APPS += namedapp
 endif
 
diff --git a/apps/nshlib/Make.defs b/apps/nshlib/Make.defs
index c72c09bce..2bacb5b79 100644
--- a/apps/nshlib/Make.defs
+++ b/apps/nshlib/Make.defs
@@ -34,7 +34,7 @@
 #
 ############################################################################
 
-if ($(CONFIG_NSH_LIBRARY),y)
+ifeq ($(CONFIG_NSH_LIBRARY),y)
 CONFIGURED_APPS += nshlib
 endif
 
diff --git a/apps/system/Make.defs b/apps/system/Make.defs
index 1ddabd337..e72f56ef5 100644
--- a/apps/system/Make.defs
+++ b/apps/system/Make.defs
@@ -34,18 +34,18 @@
 #
 ############################################################################
 
-if ($(CONFIG_VSN_POWEROFF),y)
+ifeq ($(CONFIG_VSN_POWEROFF),y)
 CONFIGURED_APPS += vsn/poweroff
 endif
 
-if ($(CONFIG_VSN_RAMTRON),y)
+ifeq ($(CONFIG_VSN_RAMTRON),y)
 CONFIGURED_APPS += vsn/ramtron
 endif
 
-if ($(CONFIG_VSN_SDCARD),y)
+ifeq ($(CONFIG_VSN_SDCARD),y)
 CONFIGURED_APPS += vsn/sdcard
 endif
 
-if ($(CONFIG_VSN_SYSINFO),y)
+ifeq ($(CONFIG_VSN_SYSINFO),y)
 CONFIGURED_APPS += vsn/sysinfo
 endif
diff --git a/apps/system/readline/readline.c b/apps/system/readline/readline.c
index f7fa6a635..bdd39e67b 100644
--- a/apps/system/readline/readline.c
+++ b/apps/system/readline/readline.c
@@ -103,13 +103,34 @@ static inline int readline_rawgetc(int infd)
   char buffer;
   ssize_t nread;
 
-  nread = read(infd, &buffer, 1);
-  if (nread < 1)
+  /* Loop until we successfully read a character (or until an unexpected
+   * error occurs).
+   */
+
+  do
     {
-      /* Return EOF if the end of file (0) or error (-1) occurs */
+      /* Read one character from the incoming stream */
+
+      nread = read(infd, &buffer, 1);
+
+      /* Return EOF if the end of file (0) or error (-1) occurs. */
+ 
+      if (nread < 1)
+        {
+          /* EINTR is not really an error; it simply means that a signal we
+           * received while watiing for intput.
+           */
 
-      return EOF;
+          if (nread == 0 ||  errno != EINTR)
+            {
+              return EOF;
+            }
+        }
     }
+  while (nread < 1);
+
+  /* On success, returnt he character that was read */
+
   return (int)buffer;
 }
 
@@ -121,7 +142,26 @@ static inline int readline_rawgetc(int infd)
 static inline void readline_consoleputc(int ch, int outfd)
 {
   char buffer = ch;
-  (void)write(outfd, &buffer, 1);
+  ssize_t nwritten;
+
+  /* Loop until we successfully write a character (or until an unexpected
+   * error occurs).
+   */
+
+  do
+    {
+      /* Write the character to the outgoing stream */
+
+      nwritten = write(outfd, &buffer, 1);
+
+      /* Check for irrecoverable write errors. */
+ 
+      if (nwritten < 0 && errno != EINTR)
+        {
+          break;
+        }
+    }
+  while (nwritten < 1);
 }
 #endif
 
diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index 364de21a3..48f1866c3 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -3154,3 +3154,17 @@
 	* arch/arm/src/stm32/stm32f2xx_dma.c and stm32f4xx_dma.c: Backed out the
 	  DMA priority change just above.  The reduced SD card frequency was
 	  necessary and sufficient to resolve the problem.
+	* drivers/serial/serial.c:  open, read, write, and poll methods may now
+	  abort return EINTR (or a short transfer size) if a signal is received
+	  while waiting to receive or send serial data.  This behavior is required
+	  by POSIX.
+	* include/sys/types.h:  Define NULL to be (0) if __cplusplus is defined.
+	  (contributed by Mike Smith)
+	* include/ctype.h: Remove a stray semi-colon in a definitions (Thanks
+	  Mike Smith).
+	* configs/.../Make.defs.  Fix C++ include path set-up in Make.defs file
+	  for all 8-bit AVR platforms (Thanks Richard Cochran).
+	* lib/stdio/lib_*stream.c:  Revised to handle new error return values from
+	  serial.c.
+	* arch/arm/src/stm32/stm32_spi.c:  SPI driver can now survice re-
+	  initialization (Mike Smith).
diff --git a/nuttx/TODO b/nuttx/TODO
index f9fc558ea..543d15f70 100644
--- a/nuttx/TODO
+++ b/nuttx/TODO
@@ -1,4 +1,4 @@
-NuttX TODO List (Last updated August 7, 2012)
+NuttX TODO List (Last updated August 12, 2012)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 This file summarizes known NuttX bugs, limitations, inconsistencies with 
@@ -16,7 +16,7 @@ nuttx/
  (17)  Network (net/, drivers/net)
   (3)  USB (drivers/usbdev, drivers/usbhost)
  (11)  Libraries (lib/)
- (10)  File system/Generic drivers (fs/, drivers/)
+  (9)  File system/Generic drivers (fs/, drivers/)
   (5)  Graphics subystem (graphics/)
   (1)  Pascal add-on (pcode/)
   (1)  Documentation (Documentation/)
@@ -750,21 +750,6 @@ o File system / Generic drivers (fs/, drivers/)
   Status:      Open
   Priority:    Low
 
-  Title:       SERIAL DRIVER DOES NOT RETURN WHEN SIGNAL RECEIVED
-  Description: The serial driver (drivers/serial) should return with an
-               error and errno=EINTR when an interrupt is received.  However,
-               the serial driver just continues waiting:
-
-               static void uart_takesem(FAR sem_t *sem)
-               {
-                 while (sem_wait(sem) != 0)
-                   {
-                     ASSERT(*get_errno_ptr() == EINTR);
-                   }
-               }
-  Status:      Open
-  Priority     Medium
-
   Title:       POLLHUP SUPPORT
   Description: All drivers that support the poll method should also report
                POLLHUP event when the driver is closedd.
diff --git a/nuttx/arch/Kconfig b/nuttx/arch/Kconfig
index 253151a3b..6e0e0fb9d 100644
--- a/nuttx/arch/Kconfig
+++ b/nuttx/arch/Kconfig
@@ -20,7 +20,7 @@ config ARCH_ARM
 config ARCH_AVR
 	bool "AVR"
 	---help---
-		Atmel 9-bit bit AVR and 32-bit AVR32 architectures
+		Atmel 8-bit bit AVR and 32-bit AVR32 architectures
 
 config ARCH_HC
 	bool "Freescale HC"
diff --git a/nuttx/arch/arm/src/stm32/stm32_spi.c b/nuttx/arch/arm/src/stm32/stm32_spi.c
index a65f1e1eb..40b1a29a0 100644
--- a/nuttx/arch/arm/src/stm32/stm32_spi.c
+++ b/nuttx/arch/arm/src/stm32/stm32_spi.c
@@ -1370,9 +1370,8 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
 
       /* Only configure if the port is not already configured */
 
-      if (!(spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_SPE))
+      if ((spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_SPE) == 0)
         {
-
           /* Configure SPI1 pins: SCK, MISO, and MOSI */
 
           stm32_configgpio(GPIO_SPI1_SCK);
@@ -1395,19 +1394,18 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
 
       /* Only configure if the port is not already configured */
 
-      if (!(spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_SPE))
+      if ((spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_SPE) == 0)
         {
+          /* Configure SPI2 pins: SCK, MISO, and MOSI */
 
-        /* Configure SPI2 pins: SCK, MISO, and MOSI */
-
-        stm32_configgpio(GPIO_SPI2_SCK);
-        stm32_configgpio(GPIO_SPI2_MISO);
-        stm32_configgpio(GPIO_SPI2_MOSI);
+          stm32_configgpio(GPIO_SPI2_SCK);
+          stm32_configgpio(GPIO_SPI2_MISO);
+          stm32_configgpio(GPIO_SPI2_MOSI);
 
-        /* Set up default configuration: Master, 8-bit, etc. */
+          /* Set up default configuration: Master, 8-bit, etc. */
 
-        spi_portinitialize(priv);
-      }
+          spi_portinitialize(priv);
+        }
     }
   else
 #endif
@@ -1420,9 +1418,8 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
 
       /* Only configure if the port is not already configured */
 
-      if (!(spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_SPE))
+      if ((spi_getreg(priv, STM32_SPI_CR1_OFFSET) & SPI_CR1_SPE) == 0)
         {
-
           /* Configure SPI3 pins: SCK, MISO, and MOSI */
 
           stm32_configgpio(GPIO_SPI3_SCK);
@@ -1432,7 +1429,7 @@ FAR struct spi_dev_s *up_spiinitialize(int port)
           /* Set up default configuration: Master, 8-bit, etc. */
 
           spi_portinitialize(priv);
-      }
+        }
     }
 #endif
 
diff --git a/nuttx/drivers/serial/serial.c b/nuttx/drivers/serial/serial.c
index ea4ceb0c0..b289bb80b 100644
--- a/nuttx/drivers/serial/serial.c
+++ b/nuttx/drivers/serial/serial.c
@@ -113,16 +113,29 @@ static const struct file_operations g_serialops =
  * Name: uart_takesem
  ************************************************************************************/
 
-static void uart_takesem(FAR sem_t *sem)
+static int uart_takesem(FAR sem_t *sem, bool errout)
 {
-  while (sem_wait(sem) != 0)
+  /* Loop, ignoring interrupts, until we have successfully acquired the semaphore */
+
+  while (sem_wait(sem) != OK)
     {
-      /* The only case that an error should occur here is if
-       * the wait was awakened by a signal.
+      /* The only case that an error should occur here is if the wait was awakened
+       * by a signal.
        */
 
       ASSERT(get_errno() == EINTR);
+
+      /* When the signal is received, should we errout? Or should we just continue
+       * waiting until we have the semaphore?
+       */
+
+      if (errout)
+        {
+          return -EINTR;
+        }
     }
+
+  return OK;
 }
 
 /************************************************************************************
@@ -162,10 +175,11 @@ static void uart_pollnotify(FAR uart_dev_t *dev, pollevent_t eventset)
  * Name: uart_putxmitchar
  ************************************************************************************/
 
-static void uart_putxmitchar(FAR uart_dev_t *dev, int ch)
+static int uart_putxmitchar(FAR uart_dev_t *dev, int ch)
 {
   irqstate_t flags;
   int nexthead;
+  int ret;
 
   /* Increment to see what the next head pointer will be.  We need to use the "next"
    * head pointer to determine when the circular buffer would overrun
@@ -185,36 +199,50 @@ static void uart_putxmitchar(FAR uart_dev_t *dev, int ch)
         {
           dev->xmit.buffer[dev->xmit.head] = ch;
           dev->xmit.head = nexthead;
-          return;
+          return OK;
         }
       else
         {
-          /* Inform the interrupt level logic that we are waiting.
-           * This and the following steps must be atomic.
+          /* Inform the interrupt level logic that we are waiting. This and
+           * the following steps must be atomic.
            */
 
           flags = irqsave();
           dev->xmitwaiting = true;
 
-          /* Wait for some characters to be sent from the buffer
-           * with the TX interrupt enabled.  When the TX interrupt
-           * is enabled, uart_xmitchars should execute and remove
-           * some of the data from the TX buffer.
+          /* Wait for some characters to be sent from the buffer with the TX
+           * interrupt enabled.  When the TX interrupt is enabled, uart_xmitchars
+           * should execute and remove some of the data from the TX buffer.
            */
 
           uart_enabletxint(dev);
-          uart_takesem(&dev->xmitsem);
+          ret = uart_takesem(&dev->xmitsem, true);
           uart_disabletxint(dev);
           irqrestore(flags);
+
+          /* Check if we were awakened by signal. */
+
+          if (ret < 0)
+            {
+             /* A signal received while waiting for the xmit buffer to become
+              * non-full will abort the transfer.
+              */
+
+              return -EINTR;
+            }
         }
     }
+
+  /* We won't get here */
+
+  return OK;
 }
 
 /************************************************************************************
  * Name: uart_irqwrite
  ************************************************************************************/
 
-static ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t buflen)
+static inline ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t buflen)
 {
   ssize_t ret = buflen;
 
@@ -223,14 +251,17 @@ static ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t
   for (; buflen; buflen--)
     {
       int ch = *buffer++;
-      uart_putc(ch);
 
-     /* If this is the console, then we should replace LF with LF-CR */
+     /* If this is the console, then we should replace LF with CR-LF */
 
       if (ch == '\n')
         {
           uart_putc('\r');
         }
+
+      /* Output the character, using the low-level direct UART interfaces */
+
+      uart_putc(ch);
     }
 
   return ret;
@@ -242,18 +273,22 @@ static ssize_t uart_irqwrite(FAR uart_dev_t *dev, FAR const char *buffer, size_t
 
 static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t buflen)
 {
-  FAR struct inode *inode = filep->f_inode;
-  FAR uart_dev_t   *dev   = inode->i_private;
-  ssize_t           ret   = buflen;
-
-  /* We may receive console writes through this path from
-   * interrupt handlers and from debug output in the IDLE task!
-   * In these cases, we will need to do things a little
-   * differently.
+  FAR struct inode *inode  = filep->f_inode;
+  FAR uart_dev_t   *dev    = inode->i_private;
+  ssize_t           nread  = buflen;
+  int               ret;
+
+  /* We may receive console writes through this path from interrupt handlers and
+   * from debug output in the IDLE task!  In these cases, we will need to do things
+   * a little differently.
    */
 
   if (up_interrupt_context() || getpid() == 0)
     {
+      /* up_putc() will be used to generate the output in a busy-wait loop.
+       * up_putc() is only available for the console device.
+       */
+
       if (dev->isconsole)
         {
           irqstate_t flags = irqsave();
@@ -263,13 +298,22 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
         }
       else
         {
-          return ERROR;
+          return -EPERM;
         }
     }
 
-  /* Only one user can be accessing dev->xmit.head at once */
+  /* Only one user can access dev->xmit.head at a time */
 
-  uart_takesem(&dev->xmit.sem);
+  ret = (ssize_t)uart_takesem(&dev->xmit.sem, true);
+  if (ret < 0)
+    {
+      /* A signal received while waiting for access to the xmit.head will
+       * abort the transfer.  After the transfer has started, we are committed
+       * and signals will be ignored.
+       */
+
+      return ret;
+    }
 
   /* Loop while we still have data to copy to the transmit buffer.
    * we add data to the head of the buffer; uart_xmitchars takes the
@@ -281,15 +325,50 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
     {
       int ch = *buffer++;
 
+      /* If the ONLCR flag is set, we should translate \n to \r\n */
+
+      ret = OK;
+      if ((ch == '\n') && (dev->termios_s.c_oflag && ONLCR))
+        {
+          ret = uart_putxmitchar(dev, '\r');
+        }
+
       /* Put the character into the transmit buffer */
 
-      uart_putxmitchar(dev, ch);
+      if (ret == OK)
+        {
+          ret = uart_putxmitchar(dev, ch);
+        }
 
-      /* If this is the console, then we should replace LF with LF-CR */
+      /* Were we awakened by a signal?  That should be the only condition that
+       * uart_putxmitchar() should return an error.
+       */
 
-      if ((dev->termios_s.c_oflag && ONLCR) && ch == '\n')
+      if (ret < 0)
         {
-          uart_putxmitchar(dev, '\r');
+          /* POSIX requires that we return -1 and errno set if no data was
+           * transferred.  Otherwise, we return the number of bytes in the
+           * interrupted transfer.
+           */
+
+          if (buflen < nread)
+            {
+              /* Some data was transferred.  Return the number of bytes that were
+               * successfully transferred.
+               */
+
+              nread -= buflen;
+            }
+          else
+            {
+              /* No data was transferred. Return -EINTR.  The VFS layer will
+               * set the errno value appropriately).
+               */
+ 
+              nread = -EINTR;
+            }
+
+          break;
         }
     }
 
@@ -299,7 +378,7 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
     }
 
   uart_givesem(&dev->xmit.sem);
-  return ret;
+  return nread;
 }
 
 /************************************************************************************
@@ -313,10 +392,20 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
   irqstate_t        flags;
   ssize_t           recvd = 0;
   int16_t           tail;
+  int               ret;
+
+  /* Only one user can access dev->recv.tail at a time */
 
-  /* Only one user can be accessing dev->recv.tail at once */
+  ret = uart_takesem(&dev->recv.sem, true);
+  if (ret < 0)
+    {
+      /* A signal received while waiting for access to the recv.tail will avort
+       * the transfer.  After the transfer has started, we are committed and
+       * signals will be ignored.
+       */
 
-  uart_takesem(&dev->recv.sem);
+      return ret;
+    }
 
   /* Loop while we still have data to copy to the receive buffer.
    * we add data to the head of the buffer; uart_xmitchars takes the
@@ -353,6 +442,7 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
             {
               tail = 0;
             }
+
           dev->recv.tail = tail;
         }
 
@@ -427,12 +517,34 @@ static ssize_t uart_read(FAR struct file *filep, FAR char *buffer, size_t buflen
               uart_enablerxint(dev);
 
               /* Now wait with the Rx interrupt re-enabled.  NuttX will
-               * automatically re-enable global interrupts when this
-               * thread goes to sleep.
+               * automatically re-enable global interrupts when this thread
+               * goes to sleep.
                */
 
-              uart_takesem(&dev->recvsem);
+              ret = uart_takesem(&dev->recvsem, true);
               irqrestore(flags);
+
+              /* Was a signal received while waiting for data to be received? */
+
+              if (ret < 0)
+                {
+                  /* POSIX requires that we return after a signal is received.
+                   * If some bytes were read, we need to return the number of bytes
+                   * read; if no bytes were read, we need to return -1 with the
+                   * errno set correctly.
+                   */
+
+                  if (recvd == 0)
+                    {
+                      /* No bytes were read, return -EINTR (the VFS layer will
+                       * set the errno value appropriately.
+                       */
+
+                      recvd = -EINTR;
+                    }
+
+                  break;
+                }
             }
           else
             {
@@ -513,7 +625,7 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
   FAR uart_dev_t   *dev   = inode->i_private;
   pollevent_t       eventset;
   int               ndx;
-  int               ret   = OK;
+  int               ret;
   int               i;
 
   /* Some sanity checking */
@@ -527,7 +639,16 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
 
   /* Are we setting up the poll?  Or tearing it down? */
 
-  uart_takesem(&dev->pollsem);
+  ret = uart_takesem(&dev->pollsem, true);
+  if (ret < 0)
+    {
+      /* A signal received while waiting for access to the poll data
+       * will abort the operation.
+       */
+
+      return ret;
+    }
+
   if (setup)
     {
       /* This is a request to set up the poll.  Find an available
@@ -555,31 +676,43 @@ int uart_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup)
           goto errout;
         }
 
-      /* Should immediately notify on any of the requested events?
+      /* Should we immediately notify on any of the requested events?
        * First, check if the xmit buffer is full.
+       *
+       * Get exclusive access to the xmit buffer indices.  NOTE: that we do not
+       * let this wait be interrupted by a signal (we probably should, but that
+       * would be a little awkward).
        */
 
       eventset = 0;
+      (void)uart_takesem(&dev->xmit.sem, false);
 
-      uart_takesem(&dev->xmit.sem);
       ndx = dev->xmit.head + 1;
       if (ndx >= dev->xmit.size)
         {
           ndx = 0;
         }
+
       if (ndx != dev->xmit.tail)
        {
          eventset |= POLLOUT;
        }
+
       uart_givesem(&dev->xmit.sem);
 
-      /* Check if the receive buffer is empty */
+      /* Check if the receive buffer is empty
+       *
+       * Get exclusive access to the recv buffer indices.  NOTE: that we do not
+       * let this wait be interrupted by a signal (we probably should, but that
+       * would be a little awkward).
+       */
 
-      uart_takesem(&dev->recv.sem);
+      (void)uart_takesem(&dev->recv.sem, false);
       if (dev->recv.head != dev->recv.tail)
        {
          eventset |= POLLIN;
        }
+
       uart_givesem(&dev->recv.sem);
 
       if (eventset)
@@ -629,7 +762,13 @@ static int uart_close(FAR struct file *filep)
   FAR uart_dev_t   *dev   = inode->i_private;
   irqstate_t        flags;
 
-  uart_takesem(&dev->closesem);
+  /* Get exclusive access to the close semaphore (to synchronize open/close operations.
+   * NOTE: that we do not let this wait be interrupted by a signal.  Technically, we
+   * should, but almost no one every checks the return value from close() so we avoid
+   * a potential memory leak by ignoring signals in this case.
+   */
+
+  (void)uart_takesem(&dev->closesem, false);
   if (dev->open_count > 1)
     {
       dev->open_count--;
@@ -694,11 +833,19 @@ static int uart_open(FAR struct file *filep)
   struct inode *inode = filep->f_inode;
   uart_dev_t   *dev   = inode->i_private;
   uint8_t       tmp;
-  int           ret   = OK;
+  int           ret;
 
-  /* If the port is the middle of closing, wait until the close is finished */
+  /* If the port is the middle of closing, wait until the close is finished.
+   * If a signal is received while we are waiting, then return EINTR.
+   */
+
+  ret = uart_takesem(&dev->closesem, true);
+  if (ret < 0)
+    {
+      /* A signal received while waiting for the last close operation. */
 
-  uart_takesem(&dev->closesem);
+      return ret;
+    }
 
   /* Start up serial port */
   /* Increment the count of references to the device. */
diff --git a/nuttx/include/ctype.h b/nuttx/include/ctype.h
index 6959a44b1..22b325eef 100644
--- a/nuttx/include/ctype.h
+++ b/nuttx/include/ctype.h
@@ -72,7 +72,7 @@
  *
  ****************************************************************************/
 
-#define isascii(c)   ((c) >= 0 && (c) <= 0x7f);
+#define isascii(c)   ((c) >= 0 && (c) <= 0x7f)
 
 /****************************************************************************
  * Name: isprint
diff --git a/nuttx/include/netinet/arp.h b/nuttx/include/netinet/arp.h
index 34cfc84a4..e318945aa 100644
--- a/nuttx/include/netinet/arp.h
+++ b/nuttx/include/netinet/arp.h
@@ -58,14 +58,17 @@
 #define SIOCDARP        _ARPIOC(2) /* Delete an ARP mapping */
 #define SIOCGARP        _ARPIOC(3) /* Get an ARP mapping */
 
-/* Values for the FLAGS field in struct arpreq */
-
-#define ATF_COM         0x01       /* Lookup complete */
-#define ATF_PERM        0x02       /* Permanent entry */
-#define ATF_PUBL        0x04       /* Publish entry */
-#define ATF_USETRAILERS 0x10       /* Trailers requested */
-#define ATF_NETMASK     0x20       /* Use a netmask */
-#define ATF_DONTPUB     0x40       /* Don't answer */
+/* Definitions for bits in field arp_flags of struct arpreq.  If the
+ * ATF_NETMASK flag is set, then arp_netmask should be valid.  This should
+ * be set to 0xffffffff, or 0 to remove an existing arp entry.
+ */
+
+#define ATF_COM         (1 << 0)   /* Lookup complete */
+#define ATF_PERM        (1 << 1)   /* Permanent entry */
+#define ATF_PUBL        (1 << 2)   /* Publish entry */
+#define ATF_USETRAILERS (1 << 3)   /* Trailers requested (obsolete) */
+#define ATF_NETMASK     (1 << 4)   /* Use a netmask */
+#define ATF_DONTPUB     (1 << 5)   /* Don't answer */
 
 /****************************************************************************
  * Public Type Definitions
diff --git a/nuttx/include/nuttx/net/ioctl.h b/nuttx/include/nuttx/net/ioctl.h
index 5bce5eaf1..be3f597f4 100644
--- a/nuttx/include/nuttx/net/ioctl.h
+++ b/nuttx/include/nuttx/net/ioctl.h
@@ -149,6 +149,7 @@
 /****************************************************************************
  * Type Definitions
  ****************************************************************************/
+/* See include/net/if.h */
 
 /****************************************************************************
  * Public Function Prototypes
diff --git a/nuttx/include/sys/types.h b/nuttx/include/sys/types.h
index 6014b9b74..2ae69d4a7 100644
--- a/nuttx/include/sys/types.h
+++ b/nuttx/include/sys/types.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * include/sys/types.h
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -63,8 +63,11 @@
 /* NULL is usually defined in stddef.h (which includes this file) */
 
 #ifndef NULL
-    /* SDCC is sensitive to NULL pointer type conversions */
-#  ifdef SDCC
+    /* SDCC is sensitive to NULL pointer type conversions, and C++ defines
+     * NULL as zero
+     */
+
+#  if defined(SDCC) || defined(__cplusplus)
 #    define NULL (0)
 #  else
 #    define NULL ((void*)0)
diff --git a/nuttx/lib/Makefile b/nuttx/lib/Makefile
index 772c6f6a8..fc8f0c4dd 100644
--- a/nuttx/lib/Makefile
+++ b/nuttx/lib/Makefile
@@ -34,6 +34,13 @@
 ###########################################################################
 
 -include $(TOPDIR)/Make.defs
+
+ASRCS =
+CSRCS =
+
+DEPPATH := --dep-path .
+VPATH := .
+
 include stdio/Make.defs
 include stdlib/Make.defs
 include unistd/Make.defs
@@ -52,41 +59,12 @@ include termios/Make.defs
 include queue/Make.defs
 include misc/Make.defs
 
-ASRCS = 
 AOBJS = $(ASRCS:.S=$(OBJEXT))
-
-CSRCS = $(STDIO_SRCS) $(STDLIB_SRCS) $(UNISTD_SRCS)  $(SCHED_SRCS) \
-		  $(STRING_SRCS) $(PTHREAD_SRCS) $(SEM_SRCS) $(SIG_SRCS) $(MQUEUE_SRCS) \
-		  $(MATH_SRCS) $(NET_SRCS) $(TIME_SRCS) $(LIBGEN_SRCS) \
-		  $(DIRENT_SRCS) $(TERMIOS_SRCS) \
-		  $(QUEUE_SRCS) $(MISC_SRCS) $(REGEX_SRCS) $(CRC_SRCS) $(DBG_SRCS) 
 COBJS = $(CSRCS:.c=$(OBJEXT))
 
 SRCS = $(ASRCS) $(CSRCS)
 OBJS = $(AOBJS) $(COBJS)
 
-ROOTDEPPATH	= --dep-path .
-STDIODEPPATH = --dep-path stdio
-STDLIBDEPPATH = --dep-path stdlib
-UNISTDDEPPATH = --dep-path unistd
-SCHEDDEPPATH = --dep-path sched
-STRINGDEPPATH = --dep-path string
-PTHREADDEPPATH = --dep-path pthread
-SEMDEPPATH = --dep-path semaphore
-SIGDEPPATH = --dep-path signal
-MQDEPPATH = --dep-path mqueue
-MATHDEPPATH = --dep-path math
-NETDEPPATH = --dep-path net
-TIMEDEPPATH = --dep-path time
-LIBGENDEPPATH = --dep-path libgen
-DIRENTDEPPATH = --dep-path dirent
-TERMIOSDEPPATH = --dep-path termios
-QUEUEDEPPATH = --dep-path queue
-MISCDEPPATH = --dep-path misc
-
-VPATH  = stdio:stdlib:unistd:sched:string:pthread:semaphore:signal:mqueue
-VPATH += :math:net:time:libgen:dirent:termios:queue:misc
-
 UBIN = libulib$(LIBEXT)
 KBIN = libklib$(LIBEXT)
 BIN  = liblib$(LIBEXT)
@@ -121,12 +99,7 @@ $(KBIN): uclean .kernlib
 endif
 
 .depend: Makefile $(SRCS)
-	@$(MKDEP) $(ROOTDEPPATH) $(STDIODEPPATH) $(STDLIBDEPPATH) \
-	  $(UNISTDDEPPATH) $(SCHEDDEPPATH) $(STRINGDEPPATH) $(PTHREADDEPPATH) \
-	  $(SEMDEPPATH) $(SIGDEPPATH) $(MQDEPPATH) $(MATHDEPPATH) $(NETDEPPATH)  \
-	  $(TIMEDEPPATH) $(LIBGENDEPPATH) $(DIRENTDEPPATH) $(TERMIOSDEPPATH) \
-	  $(QUEUEDEPPATH) $(MISCDEPPATH) \
-	  $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@$(MKDEP) $(DEPPATH) $(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
 	@touch $@
 
 depend: .depend
diff --git a/nuttx/lib/dirent/Make.defs b/nuttx/lib/dirent/Make.defs
index d9dc8c29b..cc1d6b783 100644
--- a/nuttx/lib/dirent/Make.defs
+++ b/nuttx/lib/dirent/Make.defs
@@ -33,8 +33,16 @@
 #
 ############################################################################
 
-DIRENT_SRCS = 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
-DIRENT_SRCS += lib_readdirr.c lib_telldir.c
+
+# Add the dirent C files to the build
+
+CSRCS += lib_readdirr.c lib_telldir.c
+
+# Add the dirent directory to the build
+
+DEPPATH += --dep-path dirent
+VPATH += :dirent
+
 endif
 
diff --git a/nuttx/lib/libgen/Make.defs b/nuttx/lib/libgen/Make.defs
index 93214eadb..f12645512 100644
--- a/nuttx/lib/libgen/Make.defs
+++ b/nuttx/lib/libgen/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/libgen/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,11 @@
 #
 ############################################################################
 
-LIBGEN_SRCS = lib_basename.c lib_dirname.c
+# Add the libgen C files to the build
 
+CSRCS += lib_basename.c lib_dirname.c
+
+# Add the libgen directory to the build
+
+DEPPATH += --dep-path libgen
+VPATH += :libgen
diff --git a/nuttx/lib/math/Make.defs b/nuttx/lib/math/Make.defs
index c3b071298..126cd2f47 100644
--- a/nuttx/lib/math/Make.defs
+++ b/nuttx/lib/math/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/math/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,11 @@
 #
 ############################################################################
 
-MATH_SRCS = lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c lib_b16atan2.c
+# Add the math C files to the build
 
+CSRCS += lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c lib_b16atan2.c
+
+# Add the math directory to the build
+
+DEPPATH += --dep-path math
+VPATH += :math
diff --git a/nuttx/lib/misc/Make.defs b/nuttx/lib/misc/Make.defs
index 8892f71e6..484f822d0 100644
--- a/nuttx/lib/misc/Make.defs
+++ b/nuttx/lib/misc/Make.defs
@@ -33,18 +33,23 @@
 #
 ############################################################################
 
-MISC_SRCS = lib_init.c lib_filesem.c
+# Add the internal C files to the build
+
+CSRCS += lib_init.c lib_filesem.c
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
 ifneq ($(CONFIG_NFILE_STREAMS),0)
-MISC_SRCS += lib_streamsem.c
+CSRCS += lib_streamsem.c
 endif
 endif
 
-REGEX_SRCS = lib_match.c
-
-CRC_SRCS = lib_crc32.c
+# Add the miscellaneous C files to the build
 
-DBG_SRCS = lib_dbg.c lib_dumpbuffer.c
+CSRCS += lib_match.c
+CSRCS += lib_crc32.c
+CSRCS += lib_dbg.c lib_dumpbuffer.c
 
+# Add the misc directory to the build
 
+DEPPATH += --dep-path misc
+VPATH += :misc
diff --git a/nuttx/lib/mqueue/Make.defs b/nuttx/lib/mqueue/Make.defs
index cd2091e99..40dc6c13e 100644
--- a/nuttx/lib/mqueue/Make.defs
+++ b/nuttx/lib/mqueue/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/mqueue/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -34,6 +34,15 @@
 ############################################################################
 
 ifneq ($(CONFIG_DISABLE_MQUEUE),y)
-MQUEUE_SRCS	= mq_setattr.c mq_getattr.c
+
+# Add the mqueue C files to the build
+
+CSRCS += mq_setattr.c mq_getattr.c
+
+# Add the mqueue directory to the build
+
+DEPPATH += --dep-path mqueue
+VPATH += :mqueue
+
 endif
 
diff --git a/nuttx/lib/net/Make.defs b/nuttx/lib/net/Make.defs
index 94ac6db03..ae041bd2c 100644
--- a/nuttx/lib/net/Make.defs
+++ b/nuttx/lib/net/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/net/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,12 @@
 #
 ############################################################################
 
-NET_SRCS  = lib_etherntoa.c lib_htons.c lib_htonl.c lib_inetaddr.c
-NET_SRCS += lib_inetntoa.c lib_inetntop.c lib_inetpton.c
+# Add the networking C files to the build
+
+CSRCS += lib_etherntoa.c lib_htons.c lib_htonl.c lib_inetaddr.c
+CSRCS += lib_inetntoa.c lib_inetntop.c lib_inetpton.c
+
+# Add the net directory to the build
+
+DEPPATH += --dep-path net
+VPATH += :net
diff --git a/nuttx/lib/pthread/Make.defs b/nuttx/lib/pthread/Make.defs
index 47211f9b9..a1eba7bb0 100644
--- a/nuttx/lib/pthread/Make.defs
+++ b/nuttx/lib/pthread/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/pthread/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,7 +33,9 @@
 #
 ############################################################################
 
-PTHREAD_SRCS = pthread_attrinit.c pthread_attrdestroy.c \
+# Add the pthread C files to the build
+
+CSRCS += pthread_attrinit.c pthread_attrdestroy.c \
 		  pthread_attrsetschedpolicy.c pthread_attrgetschedpolicy.c \
 		  pthread_attrsetinheritsched.c pthread_attrgetinheritsched.c \
 		  pthread_attrsetstacksize.c pthread_attrgetstacksize.c \
@@ -45,5 +47,10 @@ PTHREAD_SRCS = pthread_attrinit.c pthread_attrdestroy.c \
 		  pthread_mutexattrgetpshared.c pthread_mutexattrsetpshared.c
 
 ifeq ($(CONFIG_MUTEX_TYPES),y)
-PTHREAD_SRCS += pthread_mutexattrsettype.c pthread_mutexattrgettype.c
+CSRCS += pthread_mutexattrsettype.c pthread_mutexattrgettype.c
 endif
+
+# Add the pthread directory to the build
+
+DEPPATH += --dep-path pthread
+VPATH += :pthread
diff --git a/nuttx/lib/queue/Make.defs b/nuttx/lib/queue/Make.defs
index 94e8125e7..976e7a2b8 100644
--- a/nuttx/lib/queue/Make.defs
+++ b/nuttx/lib/queue/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/queue/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,8 +33,15 @@
 #
 ############################################################################
 
-QUEUE_SRCS = sq_addlast.c sq_addfirst.c sq_addafter.c \
+# Add the queue C files to the build
+
+CSRCS += sq_addlast.c sq_addfirst.c sq_addafter.c \
 		  sq_rem.c sq_remlast.c sq_remfirst.c sq_remafter.c
 
-QUEUE_SRCS += dq_addlast.c dq_addfirst.c dq_addafter.c dq_addbefore.c \
+CSRCS += dq_addlast.c dq_addfirst.c dq_addafter.c dq_addbefore.c \
 		  dq_rem.c dq_remlast.c dq_remfirst.c
+
+# Add the queue directory to the build
+
+DEPPATH += --dep-path queue
+VPATH += :queue
diff --git a/nuttx/lib/sched/Make.defs b/nuttx/lib/sched/Make.defs
index 939cb983f..f398b755e 100644
--- a/nuttx/lib/sched/Make.defs
+++ b/nuttx/lib/sched/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/sched/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,6 +33,11 @@
 #
 ############################################################################
 
-SCHED_SRCS = sched_getprioritymax.c sched_getprioritymin.c
+# Add the sched C files to the build
 
+CSRCS += sched_getprioritymax.c sched_getprioritymin.c
 
+# Add the sched directory to the build
+
+DEPPATH += --dep-path sched
+VPATH += :sched
diff --git a/nuttx/lib/semaphore/Make.defs b/nuttx/lib/semaphore/Make.defs
index 996d320fe..fdc0fe7d5 100644
--- a/nuttx/lib/semaphore/Make.defs
+++ b/nuttx/lib/semaphore/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/semaphore/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,4 +33,11 @@
 #
 ############################################################################
 
-SEM_SRCS = sem_init.c sem_getvalue.c
+# Add the semaphore C files to the build
+
+CSRCS += sem_init.c sem_getvalue.c
+
+# Add the semaphore directory to the build
+
+DEPPATH += --dep-path semaphore
+VPATH += :semaphore
diff --git a/nuttx/lib/signal/Make.defs b/nuttx/lib/signal/Make.defs
index 0c66efa73..e27da9b2e 100644
--- a/nuttx/lib/signal/Make.defs
+++ b/nuttx/lib/signal/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/signal/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -34,7 +34,14 @@
 ############################################################################
 
 ifneq ($(CONFIG_DISABLE_SIGNALS),y)
-SIG_SRCS = sig_emptyset.c sig_fillset.c sig_addset.c sig_delset.c sig_ismember.c
-endif
 
+# Add the signal C files to the build
+
+CSRCS += sig_emptyset.c sig_fillset.c sig_addset.c sig_delset.c sig_ismember.c
+
+# Add the signal directory to the build
 
+DEPPATH += --dep-path signal
+VPATH += :signal
+
+endif
diff --git a/nuttx/lib/stdio/Make.defs b/nuttx/lib/stdio/Make.defs
index ddccaca71..1165d5354 100644
--- a/nuttx/lib/stdio/Make.defs
+++ b/nuttx/lib/stdio/Make.defs
@@ -33,7 +33,9 @@
 #
 ############################################################################
 
-STDIO_SRCS = lib_fileno.c lib_printf.c lib_rawprintf.c lib_lowprintf.c \
+# Add the stdio C files to the build
+
+CSRCS += lib_fileno.c lib_printf.c lib_rawprintf.c lib_lowprintf.c \
 		  lib_sprintf.c lib_asprintf.c lib_snprintf.c lib_libsprintf.c \
 		  lib_vsprintf.c lib_avsprintf.c lib_vsnprintf.c lib_libvsprintf.c \
 		  lib_meminstream.c lib_memoutstream.c lib_lowinstream.c \
@@ -41,9 +43,9 @@ STDIO_SRCS = lib_fileno.c lib_printf.c lib_rawprintf.c lib_lowprintf.c \
 		  lib_nulloutstream.c lib_sscanf.c
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
-STDIO_SRCS += lib_rawinstream.c lib_rawoutstream.c
+CSRCS += lib_rawinstream.c lib_rawoutstream.c
 ifneq ($(CONFIG_NFILE_STREAMS),0)
-STDIO_SRCS += lib_fopen.c lib_fclose.c lib_fread.c lib_libfread.c lib_fseek.c \
+CSRCS += lib_fopen.c lib_fclose.c lib_fread.c lib_libfread.c lib_fseek.c \
 		   lib_ftell.c lib_fsetpos.c lib_fgetpos.c lib_fgetc.c lib_fgets.c \
 		   lib_gets.c lib_fwrite.c lib_libfwrite.c lib_fflush.c \
 		   lib_libflushall.c lib_libfflush.c lib_rdflush.c lib_wrflush.c \
@@ -53,13 +55,18 @@ endif
 endif
 
 ifeq ($(CONFIG_SYSLOG),y)
-STDIO_SRCS += lib_syslogstream.c
+CSRCS += lib_syslogstream.c
 endif
 
 ifeq ($(CONFIG_LIBC_FLOATINGPOINT),y)
-STDIO_SRCS += lib_dtoa.c
+CSRCS += lib_dtoa.c
 endif
 
 ifeq ($(CONFIG_STDIO_LINEBUFFER),y)
-STDIO_SRCS += lib_libnoflush.c
+CSRCS += lib_libnoflush.c
 endif
+
+# Add the stdio directory to the build
+
+DEPPATH += --dep-path stdio
+VPATH += :stdio
diff --git a/nuttx/lib/stdio/lib_libfwrite.c b/nuttx/lib/stdio/lib_libfwrite.c
index e2c35e3e9..e71866b49 100644
--- a/nuttx/lib/stdio/lib_libfwrite.c
+++ b/nuttx/lib/stdio/lib_libfwrite.c
@@ -2,7 +2,7 @@
  * lib/stdio/lib_libfwrite.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
diff --git a/nuttx/lib/stdio/lib_lowinstream.c b/nuttx/lib/stdio/lib_lowinstream.c
index 6dcc4a37e..c97a4721f 100644
--- a/nuttx/lib/stdio/lib_lowinstream.c
+++ b/nuttx/lib/stdio/lib_lowinstream.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_lowinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -42,7 +42,9 @@
 #ifdef CONFIG_ARCH_LOWGETC
 
 #include <stdio.h>
+#include <assert.h>
 #include <errno.h>
+
 #include <nuttx/arch.h>
 
 #include "lib_internal.h"
@@ -57,10 +59,19 @@
 
 static int lowinstream_getc(FAR struct lib_instream_s *this)
 {
-  if (this && up_getc(ch) != EOF)
+  int ret;
+
+  DEBUGASSERT(this);
+
+  /* Get the next character from the incoming stream */
+
+  ret = up_getc(ch)
+  if (ret != EOF)
     {
       this->nget++;
     }
+
+  return ret;
 }
 
 /****************************************************************************
diff --git a/nuttx/lib/stdio/lib_lowoutstream.c b/nuttx/lib/stdio/lib_lowoutstream.c
index 726bd84d7..092f39ca2 100644
--- a/nuttx/lib/stdio/lib_lowoutstream.c
+++ b/nuttx/lib/stdio/lib_lowoutstream.c
@@ -42,6 +42,7 @@
 #ifdef CONFIG_ARCH_LOWPUTC
 
 #include <stdio.h>
+#include <assert.h>
 #include <errno.h>
 #include <nuttx/arch.h>
 
@@ -57,7 +58,9 @@
 
 static void lowoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
-  if (this && up_putc(ch) != EOF)
+  DEBUGASSERT(this);
+
+  if (up_putc(ch) != EOF)
     {
       this->nput++;
     }
diff --git a/nuttx/lib/stdio/lib_meminstream.c b/nuttx/lib/stdio/lib_meminstream.c
index 839e56219..a842096fb 100644
--- a/nuttx/lib/stdio/lib_meminstream.c
+++ b/nuttx/lib/stdio/lib_meminstream.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_meminstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -37,6 +37,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <assert.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -52,7 +54,11 @@ static int meminstream_getc(FAR struct lib_instream_s *this)
   FAR struct lib_meminstream_s *mthis = (FAR struct lib_meminstream_s *)this;
   int ret;
 
-  if (this && this->nget < mthis->buflen)
+  DEBUGASSERT(this);
+
+  /* Get the next character (if any) from the buffer */
+
+  if (this->nget < mthis->buflen)
     {
       ret = mthis->buffer[this->nget];
       this->nget++;
@@ -61,6 +67,7 @@ static int meminstream_getc(FAR struct lib_instream_s *this)
     {
       ret = EOF;
     }
+
   return ret;
 }
 
diff --git a/nuttx/lib/stdio/lib_memoutstream.c b/nuttx/lib/stdio/lib_memoutstream.c
index 007ab8976..21197358b 100644
--- a/nuttx/lib/stdio/lib_memoutstream.c
+++ b/nuttx/lib/stdio/lib_memoutstream.c
@@ -37,6 +37,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <assert.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -51,12 +53,14 @@ static void memoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_memoutstream_s *mthis = (FAR struct lib_memoutstream_s *)this;
 
+  DEBUGASSERT(this);
+
   /* If this will not overrun the buffer, then write the character to the
    * buffer.  Not that buflen was pre-decremented when the stream was
    * created so it is okay to write past the end of the buflen by one.
    */
 
-  if (this && this->nput < mthis->buflen)
+  if (this->nput < mthis->buflen)
     {
       mthis->buffer[this->nput] = ch;
       this->nput++;
diff --git a/nuttx/lib/stdio/lib_nullinstream.c b/nuttx/lib/stdio/lib_nullinstream.c
index 271cba396..0eadb0a8e 100644
--- a/nuttx/lib/stdio/lib_nullinstream.c
+++ b/nuttx/lib/stdio/lib_nullinstream.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_nullinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -39,6 +39,7 @@
 
 #include <stdio.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
diff --git a/nuttx/lib/stdio/lib_nulloutstream.c b/nuttx/lib/stdio/lib_nulloutstream.c
index 520df459e..69878fd57 100644
--- a/nuttx/lib/stdio/lib_nulloutstream.c
+++ b/nuttx/lib/stdio/lib_nulloutstream.c
@@ -38,7 +38,9 @@
  ****************************************************************************/
 
 #include <stdio.h>
+#include <assert.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -47,6 +49,7 @@
 
 static void nulloutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
+  DEBUGASSERT(this);
   this->nput++;
 }
 
diff --git a/nuttx/lib/stdio/lib_rawinstream.c b/nuttx/lib/stdio/lib_rawinstream.c
index ead3116b4..9671a2716 100644
--- a/nuttx/lib/stdio/lib_rawinstream.c
+++ b/nuttx/lib/stdio/lib_rawinstream.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_rawinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -38,7 +38,9 @@
  ****************************************************************************/
 
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -52,23 +54,26 @@
 static int rawinstream_getc(FAR struct lib_instream_s *this)
 {
   FAR struct lib_rawinstream_s *rthis = (FAR struct lib_rawinstream_s *)this;
+  int nwritten;
   char ch;
 
-  if (this && rthis->fd >= 0)
+  DEBUGASSERT(this && rthis->fd >= 0);
+
+  /* Attempt to read one character */
+
+  nwritten = read(rthis->fd, &ch, 1);
+  if (nwritten == 1)
     {
-      int nwritten;
-      do
-        {
-          nwritten = read(rthis->fd, &ch, 1);
-          if (nwritten == 1)
-            {
-              this->nget++;
-              return ch;
-            }
-        }
-      while (nwritten < 0 && get_errno() == EINTR);
+      this->nget++;
+      return ch;
     }
 
+  /* Return EOF on any failure to read from the incoming byte stream. The
+   * only expected error is EINTR meaning that the read was interrupted
+   * by a signal.  A Zero return value would indicated an end-of-file
+   * confition.
+   */
+
   return EOF;
 }
 
diff --git a/nuttx/lib/stdio/lib_rawoutstream.c b/nuttx/lib/stdio/lib_rawoutstream.c
index ce9d33280..ed813f87a 100644
--- a/nuttx/lib/stdio/lib_rawoutstream.c
+++ b/nuttx/lib/stdio/lib_rawoutstream.c
@@ -38,7 +38,9 @@
  ****************************************************************************/
 
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -52,20 +54,32 @@
 static void rawoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_rawoutstream_s *rthis = (FAR struct lib_rawoutstream_s *)this;
+  int nwritten;
   char buffer = ch;
-  if (this && rthis->fd >= 0)
+
+  DEBUGASSERT(this && rthis->fd >= 0);
+
+  /* Loop until the character is successfully transferred or until an
+   * irrecoverable error occurs.
+   */
+
+  do
     {
-      int nwritten;
-      do
+      nwritten = write(rthis->fd, &buffer, 1);
+      if (nwritten == 1)
         {
-          nwritten = write(rthis->fd, &buffer, 1);
-          if (nwritten == 1)
-            {
-              this->nput++;
-            }
+          this->nput++;
+          return;
         }
-      while (nwritten < 0 && get_errno() == EINTR);
+
+      /* The only expected error is EINTR, meaning that the write operation
+       * was awakened by a signal.  Zero would not be a valid return value
+       * from write().
+       */
+
+      DEBUGASSERT(nwritten < 0);
     }
+  while (get_errno() == EINTR);
 }
 
 /****************************************************************************
diff --git a/nuttx/lib/stdio/lib_stdinstream.c b/nuttx/lib/stdio/lib_stdinstream.c
index d89b6b63a..77aab9ec8 100644
--- a/nuttx/lib/stdio/lib_stdinstream.c
+++ b/nuttx/lib/stdio/lib_stdinstream.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_stdinstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -37,6 +37,8 @@
  * Included Files
  ****************************************************************************/
 
+#include <assert.h>
+
 #include "lib_internal.h"
 
 /****************************************************************************
@@ -50,16 +52,19 @@
 static int stdinstream_getc(FAR struct lib_instream_s *this)
 {
   FAR struct lib_stdinstream_s *sthis = (FAR struct lib_stdinstream_s *)this;
-  if (this)
+  int ret;
+
+  DEBUGASSERT(this);
+
+  /* Get the next character from the incoming stream */
+
+  ret = getc(sthis->stream);
+  if (ret != EOF)
     {
-      int ret = getc(sthis->stream);
-      if (ret != EOF)
-        {
-          this->nget++;
-        }
-      return ret;
+      this->nget++;
     }
-  return EOF;
+ 
+ return ret;
 }
 
 /****************************************************************************
diff --git a/nuttx/lib/stdio/lib_stdoutstream.c b/nuttx/lib/stdio/lib_stdoutstream.c
index 12e78ce53..20da5b702 100644
--- a/nuttx/lib/stdio/lib_stdoutstream.c
+++ b/nuttx/lib/stdio/lib_stdoutstream.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_stdoutstream.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -38,6 +38,8 @@
  ****************************************************************************/
 
 #include <fcntl.h>
+#include <assert.h>
+#include <errno.h>
 
 #include "lib_internal.h"
 
@@ -52,13 +54,28 @@
 static void stdoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
   FAR struct lib_stdoutstream_s *sthis = (FAR struct lib_stdoutstream_s *)this;
-  if (this)
+  int result;
+
+  DEBUGASSERT(this && sthis->stream);
+
+  /* Loop until the character is successfully transferred or an irrecoverable
+   * error occurs.
+   */
+
+  do
     {
-      if (putc(ch, sthis->stream) != EOF)
+      result = fputc(ch, sthis->stream);
+      if (result != EOF)
         {
           this->nput++;
+          return;
         }
+
+      /* EINTR (meaning that fputc was interrupted by a signal) is the only
+       * recoverable error.
+       */
     }
+  while (get_errno() == EINTR);
 }
 
 /****************************************************************************
diff --git a/nuttx/lib/stdio/lib_syslogstream.c b/nuttx/lib/stdio/lib_syslogstream.c
index 20c6165ca..7e47d794a 100644
--- a/nuttx/lib/stdio/lib_syslogstream.c
+++ b/nuttx/lib/stdio/lib_syslogstream.c
@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 
 #include <unistd.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/syslog.h>
@@ -62,10 +63,30 @@
 
 static void syslogstream_putc(FAR struct lib_outstream_s *this, int ch)
 {
-  /* Write the character to the supported logging device */
-
-  (void)syslog_putc(ch);
-  this->nput++;
+  int ret;
+
+  /* Try writing until the write was successful or until an irrecoverable
+   * error occurs.
+   */
+
+  do
+    {
+      /* Write the character to the supported logging device */
+
+      ret = syslog_putc(ch);
+      if (ret == OK)
+        {
+          this->nput++;
+          return;
+        }
+
+      /* On failure syslog_putc will return a negated errno value.  The
+       * errno variable will not be set.  The special value -EINTR means that
+       * syslog_putc() was awakened by a signal.  This is not a real error and
+       * must be ignored in this context.
+       */
+    }
+  while (ret == -EINTR);
 }
 
 /****************************************************************************
diff --git a/nuttx/lib/stdlib/Make.defs b/nuttx/lib/stdlib/Make.defs
index 3119ecda4..76e285808 100644
--- a/nuttx/lib/stdlib/Make.defs
+++ b/nuttx/lib/stdlib/Make.defs
@@ -33,6 +33,12 @@
 #
 ############################################################################
 
-STDLIB_SRCS = lib_abs.c lib_abort.c lib_imaxabs.c lib_labs.c lib_llabs.c \
+# Add the stdlib C files to the build
+
+CSRCS += lib_abs.c lib_abort.c lib_imaxabs.c lib_labs.c lib_llabs.c \
 		  lib_rand.c lib_qsort.c
 
+# Add the stdlib directory to the build
+
+DEPPATH += --dep-path stdlib
+VPATH += :stdlib
diff --git a/nuttx/lib/string/Make.defs b/nuttx/lib/string/Make.defs
index 86fdaba02..495634a9e 100644
--- a/nuttx/lib/string/Make.defs
+++ b/nuttx/lib/string/Make.defs
@@ -33,7 +33,9 @@
 #
 ############################################################################
 
-STRING_SRCS	= lib_checkbase.c lib_isbasedigit.c lib_memset.c lib_memchr.c \
+# Add the string C files to the build
+
+CSRCS += lib_checkbase.c lib_isbasedigit.c lib_memset.c lib_memchr.c \
 		  lib_memccpy.c lib_memcpy.c lib_memcmp.c lib_memmove.c lib_skipspace.c \
 		  lib_strcasecmp.c lib_strcat.c lib_strchr.c lib_strcpy.c lib_strcmp.c \
 		  lib_strcspn.c lib_strdup.c lib_strerror.c lib_strlen.c lib_strnlen.c \
@@ -41,3 +43,8 @@ STRING_SRCS	= lib_checkbase.c lib_isbasedigit.c lib_memset.c lib_memchr.c \
 		  lib_strndup.c lib_strcasestr.c lib_strpbrk.c lib_strrchr.c\
 		  lib_strspn.c lib_strstr.c lib_strtok.c lib_strtokr.c lib_strtol.c \
 		  lib_strtoll.c lib_strtoul.c lib_strtoull.c lib_strtod.c
+
+# Add the string directory to the build
+
+DEPPATH += --dep-path string
+VPATH += :string
diff --git a/nuttx/lib/termios/Make.defs b/nuttx/lib/termios/Make.defs
index c0a090bd5..a6bb77f83 100644
--- a/nuttx/lib/termios/Make.defs
+++ b/nuttx/lib/termios/Make.defs
@@ -33,11 +33,22 @@
 #
 ############################################################################
 
-TERMIOS_SRCS =
+# termios.h support requires file descriptors and that CONFIG_SERIAL_TERMIOS
+# is defined
 
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
+ifeq ($(CONFIG_SERIAL_TERMIOS),y)
 
-TERMIOS_SRCS += lib_cfgetspeed.c lib_cfsetspeed.c lib_tcflush.c
-TERMIOS_SRCS += lib_tcgetattr.c lib_tcsetattr.c
+# Add the termios C files to the build
+
+CSRCS += lib_cfgetspeed.c lib_cfsetspeed.c lib_tcflush.c
+CSRCS += lib_tcgetattr.c lib_tcsetattr.c
+
+# Add the termios directory to the build
+
+DEPPATH += --dep-path termios
+VPATH += termios
 
 endif
+endif
+
diff --git a/nuttx/lib/time/Make.defs b/nuttx/lib/time/Make.defs
index d65ba50f6..ab7414229 100644
--- a/nuttx/lib/time/Make.defs
+++ b/nuttx/lib/time/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/time/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,5 +33,12 @@
 #
 ############################################################################
 
-TIME_SRCS = lib_mktime.c lib_gmtime.c lib_gmtimer.c lib_strftime.c \
+# Add the time C files to the build
+
+CSRCS += lib_mktime.c lib_gmtime.c lib_gmtimer.c lib_strftime.c \
 		  lib_calendar2utc.c lib_daysbeforemonth.c lib_isleapyear.c lib_time.c
+
+# Add the time directory to the build
+
+DEPPATH += --dep-path time
+VPATH += :time
diff --git a/nuttx/lib/unistd/Make.defs b/nuttx/lib/unistd/Make.defs
index 90f172406..e1441a48d 100644
--- a/nuttx/lib/unistd/Make.defs
+++ b/nuttx/lib/unistd/Make.defs
@@ -1,8 +1,8 @@
 ############################################################################
 # lib/unistd/Make.defs
 #
-#   Copyright (C) 2011 Gregory Nutt. All rights reserved.
-#   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+#   Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
+#   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -33,10 +33,17 @@
 #
 ############################################################################
 
-UNISTD_SRCS = lib_getopt.c lib_getoptargp.c lib_getoptindp.c lib_getoptoptp.c
+# Add the unistd C files to the build
+
+CSRCS += lib_getopt.c lib_getoptargp.c lib_getoptindp.c lib_getoptoptp.c
+
 ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
 ifneq ($(CONFIG_DISABLE_ENVIRON),y)
-UNISTD_SRCS +=  lib_chdir.c lib_getcwd.c
+CSRCS +=  lib_chdir.c lib_getcwd.c
 endif
 endif
 
+# Add the unistd directory to the build
+
+DEPPATH += --dep-path unistd
+VPATH += :unistd