c5471 bringup changes

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@41 42af7a65-404d-4744-a932-0658087f49c3

13 files changed, 349 insertions, 67 deletions

diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index 13f2d7f5b..4eb565842 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -34,9 +34,6 @@
     This port uses the <a href="http://www.pjrc.com/">PJRC</a> 87C52 development system
     and the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain.
     This port will require a few more weeks before it is ready for prime time.</li>
-<li><b>Motorola (Freescale) MC68HC908GP32 Microcontroller</b>.
-    Using the Axiom CMS8GP32 development board.
-    This is next in the queue.</li>
 <li><b>Other ports</b>.
     I also have partial ports for the TI TMS320DM270 and for MIPS. 
 </ul>
diff --git a/nuttx/arch/README.txt b/nuttx/arch/README.txt
index 35279349f..07d11b9b3 100644
--- a/nuttx/arch/README.txt
+++ b/nuttx/arch/README.txt
@@ -226,10 +226,6 @@ arch/pjrc-8051
     8051 Microcontroller.  This port uses the PJRC 87C52 development system
     and the SDCC toolchain.   This port is not quite ready for prime time.
 
-arch/axiom-mc68
-    For the Motorola (Freescale) MC68HC908GP32 Microcontroller using the
-    Axiom CMS8GP32 development board. This has not yet been checked-in.
-
 arch/sim
   x86 Linux Simulation</b>.  Fully functional.
 
diff --git a/nuttx/arch/c5471/defconfig b/nuttx/arch/c5471/defconfig
index e3f8d028a..8a6d50189 100644
--- a/nuttx/arch/c5471/defconfig
+++ b/nuttx/arch/c5471/defconfig
@@ -37,11 +37,14 @@
 #
 # CONFIG_ARCH - identifies the arch subdirectory
 # CONFIG_ARCH_name - for use in C code
-# CONFIG_ROM_VECTORS - unique to arm7tdmi
+# CONFIG_ROM_VECTORS - unique to c5471
+# CONFIG_DRAM_END - the size of installed DRAM.
+#   Unique to c5471
 #
 CONFIG_ARCH=c5471
 CONFIG_ARCH_C5471=y
 CONFIG_ROM_VECTORS=n
+CONFIG_DRAM_END=0x11000000
 
 #
 # C5471 specific device driver settings
@@ -59,8 +62,8 @@ CONFIG_ROM_VECTORS=n
 # CONFIG_UART_*_2STOP - Two stop bits
 #
 CONFIG_SERIAL_IRDA_CONSOLE=n
-CONFIG_UART_IRDA_HWFLOWCONTROL=y
-CONFIG_UART_MODEM_HWFLOWCONTROL=y
+CONFIG_UART_IRDA_HWFLOWCONTROL=n
+CONFIG_UART_MODEM_HWFLOWCONTROL=n
 CONFIG_UART_IRDA_RXBUFSIZE=256
 CONFIG_UART_MODEM_RXBUFSIZE=256
 CONFIG_UART_IRDA_TXBUFSIZE=256
@@ -228,5 +231,5 @@ CONFIG_STACK_POINTER=
 CONFIG_PROC_STACK_SIZE=4096
 CONFIG_PTHREAD_STACK_MIN=256
 CONFIG_PTHREAD_STACK_DEFAULT=4096
-CONFIG_HEAP_BASE=(0x10300000+90*1024+CONFIG_PROC_STACK_SIZE)
-CONFIG_HEAP_SIZE=(0x11000000-CONFIG_HEAP_BASE)
+CONFIG_HEAP_BASE=
+CONFIG_HEAP_SIZE=
diff --git a/nuttx/arch/c5471/src/Makefile b/nuttx/arch/c5471/src/Makefile
index 97f3ae9a2..a7867f0b7 100644
--- a/nuttx/arch/c5471/src/Makefile
+++ b/nuttx/arch/c5471/src/Makefile
@@ -50,7 +50,8 @@ CSRCS		= up_initialize.c up_initialstate.c up_idle.c up_doirq.c \
 		  up_createstack.c up_usestack.c up_releasestack.c \
 		  up_exit.c up_assert.c up_blocktask.c up_unblocktask.c \
 		  up_releasepending.c up_reprioritizertr.c up_copystate.c \
-		  up_schedulesigaction.c up_sigdeliver.c up_serial.c
+		  up_schedulesigaction.c up_sigdeliver.c up_serial.c \
+		  up_delay.c up_allocateheap.c
 COBJS		= $(CSRCS:.c=.o)
 
 SRCS		= $(ASRCS) $(CSRCS)
diff --git a/nuttx/arch/c5471/src/up_allocateheap.c b/nuttx/arch/c5471/src/up_allocateheap.c
new file mode 100644
index 000000000..2d40857f8
--- /dev/null
+++ b/nuttx/arch/c5471/src/up_allocateheap.c
@@ -0,0 +1,77 @@
+/************************************************************
+ * up_allocateheap.c
+ *
+ *   Copyright (C) 2007 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 Gregory Nutt 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 <sys/types.h>
+#include <debug.h>
+#include <nuttx/arch.h>
+#include "up_internal.h"
+
+/************************************************************
+ * Private Definitions
+ ************************************************************/
+
+/************************************************************
+ * Private Data
+ ************************************************************/
+
+/************************************************************
+ * Private Functions
+ ************************************************************/
+
+/************************************************************
+ * Public Functions
+ ************************************************************/
+
+/************************************************************
+ * Name: up_allocate_heap
+ *
+ * Description:
+ *   The heap may be statically allocated by
+ *   defining CONFIG_HEAP_BASE and CONFIG_HEAP_SIZE.  If these
+ *   are not defined, then this function will be called to
+ *   dynamically set aside the heap region.
+ *
+ ************************************************************/
+
+void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
+{
+  *heap_start = (FAR void*)g_heapstart;
+  *heap_size = CONFIG_DRAM_END - g_heapstart;
+}
diff --git a/nuttx/arch/c5471/src/up_delay.c b/nuttx/arch/c5471/src/up_delay.c
new file mode 100644
index 000000000..373602d53
--- /dev/null
+++ b/nuttx/arch/c5471/src/up_delay.c
@@ -0,0 +1,102 @@
+/************************************************************
+ * up_delay.c
+ *
+ *   Copyright (C) 2007 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 Gregory Nutt 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 <sys/types.h>
+#include <unistd.h>
+#include <semaphore.h>
+#include <string.h>
+#include <errno.h>
+#include <debug.h>
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <nuttx/fs.h>
+#include <arch/serial.h>
+#include "c5471.h"
+#include "os_internal.h"
+#include "up_internal.h"
+
+/************************************************************
+ * Definitions
+ ************************************************************/
+
+#define LOOPS_PER_MSEC 1250
+
+/************************************************************
+ * Private Types
+ ************************************************************/
+
+/************************************************************
+ * Private Function Prototypes
+ ************************************************************/
+
+/************************************************************
+ * Private Variables
+ ************************************************************/
+
+/************************************************************
+ * Private Functions
+ ************************************************************/
+
+
+/************************************************************
+ * Public Funtions
+ ************************************************************/
+
+/************************************************************
+ * Name: up_delay
+ *
+ * Description:
+ *   Delay inline for the requested number of milliseconds.
+ *   NOT multi-tasking friendly.
+ *
+ ************************************************************/
+
+void up_delay(int milliseconds)
+{
+  volatile int i;
+  volatile int j;
+
+  for (i = 0; i < milliseconds; i++)
+    {
+        for (j = 0; j < LOOPS_PER_MSEC; j++)
+          {
+          }
+    }
+}
diff --git a/nuttx/arch/c5471/src/up_head.S b/nuttx/arch/c5471/src/up_head.S
index e97a52dbd..dd59b98b7 100644
--- a/nuttx/arch/c5471/src/up_head.S
+++ b/nuttx/arch/c5471/src/up_head.S
@@ -64,6 +64,7 @@
  * us and that only leaves us having to do some os specific things
  * below.
  */
+	.text
         .global __start
 	.type	__start, #function
 __start:
@@ -122,7 +123,9 @@ __start:
 	 * _sbss is the start of the BSS region (see ld.script)
 	 * _ebss is the end of the BSS regsion (see ld.script)
 	 * The idle task stack starts at the end of BSS and is
-	 * of size CONFIG_PROC_STACK_SIZE
+	 * of size CONFIG_PROC_STACK_SIZE.  The heap continues
+	 * from there until the end of memory.  See g_heapstart
+	 * below.
 	 */
 
 LC0:	.long	_sbss
@@ -134,6 +137,20 @@ LC2:	.long	_eronly	/* Where .data defaults are stored in FLASH */
 	.long	_sdata	/* Where .data needs to reside in SDRAM */
 	.long	_edata
 #endif
+	.size	__start, .-__start
+
+	/* This global variable is unsigned long g_heapstart and is
+	 * exported from here only because of its coupling to LCO
+	 * above.
+	 */
+
+	.data
+	.align	4
+	.globl	g_heapstart
+	.type	g_heapstart, object
+g_heapstart:
+	.long	_ebss+CONFIG_PROC_STACK_SIZE
+	.size	g_heapstart, .-g_heapstart
 
 	.end
 
diff --git a/nuttx/arch/c5471/src/up_initialize.c b/nuttx/arch/c5471/src/up_initialize.c
index bae36548b..86b6a9f8d 100644
--- a/nuttx/arch/c5471/src/up_initialize.c
+++ b/nuttx/arch/c5471/src/up_initialize.c
@@ -88,7 +88,9 @@ void up_initialize(void)
 
   /* Initialize the system timer interrupt */
 
+#ifndef CONFIG_SUPPRESS_INTERRUPTS
   up_timerinit();
+#endif
 
   /* Register devices */
 
diff --git a/nuttx/arch/c5471/src/up_initialstate.c b/nuttx/arch/c5471/src/up_initialstate.c
index 0309daab0..76792f695 100644
--- a/nuttx/arch/c5471/src/up_initialstate.c
+++ b/nuttx/arch/c5471/src/up_initialstate.c
@@ -83,5 +83,9 @@ void up_initial_state(_TCB *tcb)
   memset(xcp, 0, sizeof(struct xcptcontext));
   xcp->regs[REG_SP]   = (uint32)tcb->adj_stack_ptr;
   xcp->regs[REG_PC]   = (uint32)tcb->start;
+#ifdef CONFIG_SUPPRESS_INTERRUPTS
+  xcp->regs[REG_CPSR] = SVC_MODE | I_BIT | F_BIT;
+#else
   xcp->regs[REG_CPSR] = SVC_MODE | F_BIT;
+#endif
 }
diff --git a/nuttx/arch/c5471/src/up_internal.h b/nuttx/arch/c5471/src/up_internal.h
index b1256130e..7563a15fc 100644
--- a/nuttx/arch/c5471/src/up_internal.h
+++ b/nuttx/arch/c5471/src/up_internal.h
@@ -44,6 +44,11 @@
  * Definitions
  ************************************************************/
 
+/* Bring-up debug configurations */
+
+#define CONFIG_SUPPRESS_INTERRUPTS  1 /* Do not enable interrupts */
+#define CONFIG_SUPPRESS_UART_CONFIG 1 /* Do not reconfig UART */
+
 /************************************************************
  * Public Types
  ************************************************************/
@@ -57,7 +62,20 @@ typedef void (*up_vector_t)(void);
  ************************************************************/
 
 #ifndef __ASSEMBLY__
+/* This holds a references to the current interrupt level
+ * register storage structure.  If is non-NULL only during
+ * interrupt processing.
+ */
+
 extern uint32 *current_regs;
+
+/* This is the beginning of heap as provided from up_head.S.
+ * This is the first address in DRAM after the loaded
+ * program+bss+idle stack.  The end of the heap is
+ * CONFIG_DRAM_END
+ */
+
+extern uint32 g_heapstart;
 #endif
 
 /************************************************************
@@ -75,6 +93,7 @@ extern uint32 *current_regs;
 
 extern void up_copystate(uint32 *dest, uint32 *src);
 extern void up_dataabort(uint32 *regs);
+extern void up_delay(int milliseconds);
 extern void up_doirq(int irq, uint32* regs);
 extern void up_fullcontextrestore(uint32 *regs) __attribute__ ((noreturn));
 extern void up_irqinitialize(void);
diff --git a/nuttx/arch/c5471/src/up_irq.c b/nuttx/arch/c5471/src/up_irq.c
index 32c350d48..6b981c99a 100644
--- a/nuttx/arch/c5471/src/up_irq.c
+++ b/nuttx/arch/c5471/src/up_irq.c
@@ -176,7 +176,9 @@ void up_irqinitialize(void)
 
   /* And finally, enable interrupts */
 
+#ifndef CONFIG_SUPPRESS_INTERRUPTS
   irqrestore(SVC_MODE | F_BIT);
+#endif
 }
 
 /************************************************************
diff --git a/nuttx/arch/c5471/src/up_serial.c b/nuttx/arch/c5471/src/up_serial.c
index b11bfc070..7bd90ef11 100644
--- a/nuttx/arch/c5471/src/up_serial.c
+++ b/nuttx/arch/c5471/src/up_serial.c
@@ -43,6 +43,7 @@
 #include <semaphore.h>
 #include <string.h>
 #include <errno.h>
+#include <debug.h>
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 #include <nuttx/fs.h>
@@ -57,6 +58,10 @@
 
 #define BASE_BAUD     115200
 
+#if defined(CONFIG_UART_IRDA_HWFLOWCONTROL) || defined(CONFIG_UART_MODEM_HWFLOWCONTROL)
+# define CONFIG_UART_HWFLOWCONTROL
+#endif
+
 /************************************************************
  * Private Types
  ************************************************************/
@@ -93,15 +98,17 @@ struct up_dev_s
 					 * this UART */
   boolean              parity;		/* 0=none, 1=odd, 2=even */
   boolean              bits;		/* Number of bits (7 or 8) */
+#ifdef CONFIG_UART_HWFLOWCONTROL
   boolean              flowcontrol;	/* TRUE: Hardware flow control
 					 * is enabled. */
+#endif
   boolean              stopbits2;	/* TRUE: Configure with 2
 					 * stop bits instead of 1 */
   boolean              xmitwaiting;	/* TRUE: User is waiting
 					 * for space in xmit.buffer */
   boolean              recvwaiting;	/* TRUE: User is waiting
 					 * for space in recv.buffer */
-  boolean              isconsole;       /* TRUE: This is the serila console */
+  boolean              isconsole;       /* TRUE: This is the serial console */
   sem_t                closesem;	/* Looks out new opens while
 					 * close is in progress */
   sem_t                xmitsem;		/* Used to wakeup user waiting
@@ -124,7 +131,6 @@ static ssize_t up_read(struct file *filep, char *buffer, size_t buflen);
 static ssize_t up_write(struct file *filep, const char *buffer, size_t buflen);
 static int     up_ioctl(struct file *filep, int cmd, unsigned long arg);
 static void    up_uartsetup(up_dev_t *dev);
-static void    up_delay(int milliseconds);
 
 /************************************************************
  * Private Variables
@@ -150,7 +156,9 @@ static up_dev_t g_irdaport =
   .baud           = CONFIG_UART_IRDA_BAUD,
   .parity         = CONFIG_UART_IRDA_PARITY,
   .bits           = CONFIG_UART_IRDA_BITS,
-  .flowcontrol    = CONFIG_UART_IRDA_HWFLOWCONTROL,
+#ifdef CONFIG_UART_IRDA_HWFLOWCONTROL
+  .flowcontrol    = TRUE,
+#endif
   .stopbits2      = CONFIG_UART_IRDA_2STOP,
 };
 
@@ -165,7 +173,9 @@ static up_dev_t g_modemport =
   .baud           = CONFIG_UART_MODEM_BAUD,
   .parity         = CONFIG_UART_MODEM_PARITY,
   .bits           = CONFIG_UART_MODEM_BITS,
-  .flowcontrol    = CONFIG_UART_MODEM_HWFLOWCONTROL,
+#ifdef CONFIG_UART_MODEM_HWFLOWCONTROL
+  .flowcontrol    = TRUE,
+#endif
   .stopbits2      = CONFIG_UART_MODEM_2STOP,
 };
 
@@ -464,22 +474,13 @@ static inline void up_saveregisters(up_dev_t *dev)
 {
   dev->regs.ier = up_inserial(dev, UART_IER_OFFS);
   dev->regs.lcr = up_inserial(dev, UART_LCR_OFFS);
+#ifdef CONFIG_UART_HWFLOWCONTROL
   if (dev->flowcontrol)
     {
       dev->regs.efr = up_inserial(dev, UART_EFR_OFFS);
       dev->regs.tcr = up_inserial(dev, UART_TCR_OFFS);
     }
-}
-
-#define LOOPS_PER_MSEC 1250
-
-static void up_delay(int milliseconds)
-{
-  volatile int i, j;
-  for (i = 0; i < milliseconds; i++) {
-    for (j = 0; j < LOOPS_PER_MSEC; j++) {
-    }
-  }
+#endif
 }
 
 /************************************************************
@@ -582,6 +583,51 @@ static void up_xmitchars(up_dev_t *dev)
 }
 
 /************************************************************
+ * Name: up_putxmitchar
+ ************************************************************/
+
+static void up_putxmitchar(up_dev_t *dev, int ch)
+{
+  int nexthead = dev->xmit.head + 1;
+  if (nexthead >= dev->xmit.size)
+    {
+      nexthead = 0;
+    }
+
+  if (nexthead != dev->xmit.tail)
+    {
+      dev->xmit.buffer[dev->xmit.head] = ch;
+      dev->xmit.head = nexthead;
+    }
+  else
+    {
+      /* Transfer some characters with interrupts disabled */
+
+      up_xmitchars(dev);
+
+      /* If we unsuccessful in making room in the buffer.
+       * then transmit the characters with interrupts
+       * enabled and wait for result.
+       */
+
+      if (nexthead == dev->xmit.tail)
+        {
+          /* Still no space */
+
+          dev->xmitwaiting = TRUE;
+
+          /* Wait for some characters to be sent from the buffer
+           * with the TX interrupt disabled.
+           */
+
+         up_enabletxint(dev);
+         up_takesem(&dev->xmitsem);
+         up_disabletxint(dev);
+       }
+   }
+}
+
+/************************************************************
  * Name: up_interrupt
  ************************************************************/
 
@@ -665,6 +711,7 @@ static int up_interrupt(int irq, void *context)
 
 static void up_uartsetup(up_dev_t *dev)
 {
+#ifdef CONFIG_SUPPRESS_UART_CONFIG
   unsigned int cval;
   uint16  mrs;
 
@@ -701,14 +748,17 @@ static void up_uartsetup(up_dev_t *dev)
   up_setrate(dev, dev->baud);
   up_setmode(dev, cval);
 
+#ifdef CONFIG_UART_HWFLOWCONTROL
   if (dev->flowcontrol)
     {
       serial_enable_hw_flow_control(dev);
     }
   else
+#endif
     {
       serial_disable_hw_flow_control(dev);
     }
+#endif
 }
 
 /************************************************************
@@ -749,46 +799,20 @@ static ssize_t up_write(struct file *filep, const char *buffer, size_t buflen)
    */
 
   up_disabletxint(dev);
-  while (buflen)
+  for (; buflen; buflen--)
     {
-      int nexthead = dev->xmit.head + 1;
-      if (nexthead >= dev->xmit.size)
-        {
-          nexthead = 0;
-        }
-
-      if (nexthead != dev->xmit.tail)
-        {
-          dev->xmit.buffer[dev->xmit.head] = *buffer++;
-          dev->xmit.head = nexthead;
-          buflen--;
-        }
-      else
-        {
-          /* Transfer some characters with interrupts disabled */
+      int ch = *buffer++;
 
-          up_xmitchars(dev);
-
-          /* If we unsuccessful in making room in the buffer.
-           * then transmit the characters with interrupts
-           * enabled and wait for result.
-           */
-
-          if (nexthead == dev->xmit.tail)
-            {
-              /* Still no space */
+      /* Put the character into the transmit buffer */
 
-              dev->xmitwaiting = TRUE;
+      up_putxmitchar(dev, ch);
+ 
+     /* If this is the console, then we should replace LF with LF-CR */
 
-              /* Wait for some characters to be sent from the buffer
-               * with the TX interrupt disabled.
-               */
-
-             up_enabletxint(dev);
-             up_takesem(&dev->xmitsem);
-             up_disabletxint(dev);
-           }
-       }
+      if (ch == '\n')
+        {
+          up_putxmitchar(dev, '\r');
+        }
     }
 
   if (dev->xmit.head != dev->xmit.tail)
@@ -924,6 +948,10 @@ static int up_close(struct file *filep)
       return OK;
     }
 
+  /* There are no more references to the port */
+
+  dev->open_count = 0;
+
   /* Stop accepting input */
 
   up_disablerxint(dev);
@@ -1100,12 +1128,12 @@ int up_putc(int ch)
 
   /* Check for LF */
 
-  if (ch == 10)
+  if (ch == '\n')
     {
       /* Add CR */
 
       up_waittxfifonotfull(&CONSOLE_DEV);
-      up_outserialchar(&CONSOLE_DEV, 13);
+      up_outserialchar(&CONSOLE_DEV, '\r');
     }
 
   up_waittxfifonotfull(&CONSOLE_DEV);
diff --git a/nuttx/arch/pjrc-8051/README.txt b/nuttx/arch/pjrc-8051/README.txt
new file mode 100644
index 000000000..0b73373d3
--- /dev/null
+++ b/nuttx/arch/pjrc-8051/README.txt
@@ -0,0 +1,34 @@
+pjrc-8051 README
+^^^^^^^^^^^^^^^^
+
+This port uses the PJRC 87C52 development system and the SDCC toolchain.
+
+The PJRC 87C52 development system can be obtained from http://www.pjrc.com/.
+
+The SDCC toolchain is available from http://sdcc.sourceforge.net/.  All
+testing has been performed using verison 2.6.0 of the SDDC toolchain.
+
+Building the SDCC toolchain
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The SDCC toolchain is built with the standard configure/make/make install
+sequence.  However, some special actions are required to generate libraries
+compatible with this build.  First start with the usual steps
+
+  download
+  unpack
+  cd sdcc
+  ./configure
+  make
+
+But before installing,
+
+  Apply sdcc-2.6.0.patch
+  cd sdcc/device/lib
+  make model-mcs51-stack-auto
+
+Then
+
+  cd sdcc
+  make install
+