diff --git a/ChangeLog b/ChangeLog
index 82230ff0bab..ddf3e9e136d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -358,9 +358,10 @@
 
 0.3.11 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
 
-	* FEATURE: Add support for recursive mutexes.
-	* BUGFIX: Eliminate a memory leak -- contained watchdog instance was not
-	  being deleted with a POSIX timer was deleted reported by kwonsk.
-	* BUGFIX: Eliminate a deadlock condition in opendir() reported by kwonsk.
-	* BUGFIX: Fix several FAT filesystem problems reported by kwonsk (Changes
-	  not yet verified).
+	* Add support for recursive mutexes.
+	* Eliminate a memory leak -- contained watchdog instance was not being
+	  deleted with a POSIX timer was deleted reported by kwonsk.
+	* Eliminate a deadlock condition in opendir() reported by kwonsk.
+	* Fix several FAT filesystem problems reported by kwonsk (Changes not yet
+	  verified).
+	* Host simulator no longer uses Linux system calls directly; Now works with Cygwin.
diff --git a/Documentation/NuttX.html b/Documentation/NuttX.html
index 1ed7d6e62d9..43e26d663ca 100644
--- a/Documentation/NuttX.html
+++ b/Documentation/NuttX.html
@@ -1008,12 +1008,13 @@ buildroot-0.1.0 2007-03-09 &lt;spudmonkey@racsa.co.cr&gt
 <pre><ul>
 nuttx-0.3.11 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
-	* FEATURE: Add support for recursive mutexes.
-	* BUGFIX: Eliminate a memory leak -- contained watchdog instance was not
-	  being deleted with a POSIX timer was deleted reported by kwonsk.
-	* BUGFIX: Eliminate a deadlock condition in opendir() reported by kwonsk.
-	* BUGFIX: Fix several FAT filesystem problems reported by kwonsk (Changes
-	  not yet verified).
+	* Add support for recursive mutexes.
+	* Eliminate a memory leak -- contained watchdog instance was not being
+	  deleted with a POSIX timer was deleted reported by kwonsk.
+	* Eliminate a deadlock condition in opendir() reported by kwonsk.
+	* Fix several FAT filesystem problems reported by kwonsk (Changes not yet
+	  verified).
+	* Host simulator no longer uses Linux system calls directly; Now works with Cygwin.
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
diff --git a/TODO b/TODO
index aa390a918e8..89f4063897b 100644
--- a/TODO
+++ b/TODO
@@ -1,7 +1,7 @@
 NuttX TODO List (Last updated February 13, 2008)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-  (7)  Task/Scheduler (sched/)
+  (6)  Task/Scheduler (sched/)
   (1)  Dynamic loader (N/A)
   (2)  Memory Managment (mm/)
   (1)  Signals (sched/, arch/)
diff --git a/arch/sim/src/Makefile b/arch/sim/src/Makefile
index 7a5e1c7ff76..919058d93eb 100644
--- a/arch/sim/src/Makefile
+++ b/arch/sim/src/Makefile
@@ -45,24 +45,27 @@ CSRCS		= up_initialize.c up_idle.c up_interruptcontext.c \
 		  up_releasepending.c up_reprioritizertr.c \
 		  up_exit.c up_schedulesigaction.c up_allocateheap.c \
 		  up_devconsole.c
+HOSTSRCS	= up_stdio.c
 ifeq ($(CONFIG_FS_FAT),y)
 CSRCS		+= up_blockdevice.c up_deviceimage.c
 endif
 ifeq ($(CONFIG_NET),y)
 CSRCS		+= up_uipdriver.c
-SPECSRCS	+= up_tapdev.c
+HOSTSRCS	+= up_tapdev.c
 endif
 
 COBJS		= $(CSRCS:.c=$(OBJEXT))
-SPECOBJS	= $(SPECSRCS:.c=$(OBJEXT))
 
-SRCS		= $(ASRCS) $(CSRCS) $(SPECSRCS)
-OBJS		= $(AOBJS) $(COBJS) $(SPECOBJS)
+NXOBJS		= $(AOBJS) $(COBJS)
+HOSTOBJS	= $(HOSTSRCS:.c=$(OBJEXT))
+
+SRCS		= $(ASRCS) $(CSRCS) $(HOSTSRCS)
+OBJS		= $(AOBJS) $(COBJS) $(HOSTOBJS)
 
 LDFLAGS		= $(ARCHSCRIPT)
-STDLIBS	= -lc
+STDLIBS		= -lc
 ifeq ($(CONFIG_FS_FAT),y)
-STDLIBS	+= -lz
+STDLIBS		+= -lz
 endif
 
 LINKOBJS	= up_head$(OBJEXT)
@@ -78,18 +81,35 @@ $(AOBJS): %$(OBJEXT): %.S
 $(COBJS) $(LINKOBJS): %$(OBJEXT): %.c
 	$(call COMPILE, $<, $@)
 
-$(SPECOBJS): %$(OBJEXT): %.c
+$(HOSTOBJS): %$(OBJEXT): %.c
 	$(CC) -c $(HOSTCFLAGS) $< -o $@
 
-libarch$(LIBEXT): $(OBJS)
-	@( for obj in $(OBJS) ; do \
+# The architecture-specific library
+libarch$(LIBEXT): $(NXOBJS)
+	@( for obj in $(NXOBJS) ; do \
 		$(call ARCHIVE, $@, $${obj}); \
 	done ; )
 
-nuttx$(EXEEXT): $(LINKOBJS)
+# A partially linked object containing only NuttX code (no interface to host OS)
+# Change the names of most symbols that conflict with libc symbols.
+
+Linux-names.dat: nuttx-names.dat
+	@cp $^ $@
+
+Cygwin-names.dat: nuttx-names.dat
+	@cat $^ | sed -e "s/^/_/g" >$@
+
+nuttx.rel : $(HOSTOS)-names.dat $(LINKOBJS)
+	@echo "LD:  nuttx.rel"
+	@$(LD) -r $(LDFLAGS) $(LDPATHES) -o $@ $(LINKOBJS) --start-group $(LDLIBS) --end-group $(EXTRA_LIBS)
+	$(OBJCOPY) --redefine-syms=$(HOSTOS)-names.dat nuttx.rel
+
+# Generate the final NuttX binary by linking the host-specific objects with the NuttX
+# specific objects (with munged names)
+
+nuttx$(EXEEXT): nuttx.rel $(HOSTOBJS)
 	@echo "LD:  nuttx$(EXEEXT)"
-	@$(CC) $(LDFLAGS) $(LDPATHES) -o $(TOPDIR)/$@ $(LINKOBJS) \
-		-Wl,--start-group $(LDLIBS) -Wl,--end-group $(STDLIBS) $(EXTRA_LIBS)
+	@$(CC) $(LDFLAGS) $(LDPATHES) -o $(TOPDIR)/$@ nuttx.rel $(HOSTOBJS) $(STDLIBS)
 	@$(NM) $(TOPDIR)/$@ | \
 		grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw] \)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | \
 		sort > $(TOPDIR)/System.map
@@ -101,7 +121,8 @@ nuttx$(EXEEXT): $(LINKOBJS)
 depend: .depend
 
 clean:
-	@rm -f libarch$(LIBEXT) *~ .*.swp
+	@rm -f nuttx.rel libarch$(LIBEXT) *~ .*.swp
+	@rm -f nuttx.rel Linux-names.dat Cygwin-names.dat
 	$(call CLEAN)
 
 distclean: clean
diff --git a/arch/sim/src/nuttx-names.dat b/arch/sim/src/nuttx-names.dat
new file mode 100644
index 00000000000..434012bc70f
--- /dev/null
+++ b/arch/sim/src/nuttx-names.dat
@@ -0,0 +1,34 @@
+calloc       NXcalloc
+close        NXclose
+closedir     NXclosedir
+dup          NXdup
+free         NXfree
+fclose       NXfclose
+fopen        NXfopen
+fputc        NXfputc
+fread        NXfread
+fwrite       NXfwrite
+fsync        NXfsync
+gettimeofday NXgettimeofday
+ioctl        NXioctl
+lseek        NXlseek
+malloc       NXmalloc
+malloc_init  NXmalloc_init
+mkdir        NXmkdir
+mount        NXmount
+open         NXopen
+opendir      NXopendir
+read         NXread
+realloc      NXrealloc
+rewinddir    NXrewinddir
+rmdir        NXrmdir
+seekdir      NXseekdir
+select       NXselect
+socket       NXsocket
+stat         NXstat
+statfs       NXstatfs
+system       NXsystem
+umount       NXumount
+unlink       NXunlink
+write        NXwrite
+zmalloc      NXzmalloc
diff --git a/arch/sim/src/up_allocateheap.c b/arch/sim/src/up_allocateheap.c
index b464719d413..86efe7d9d05 100644
--- a/arch/sim/src/up_allocateheap.c
+++ b/arch/sim/src/up_allocateheap.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_allocateheap.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -45,25 +45,25 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
 static ubyte sim_heap[SIM_HEAP_SIZE];
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_allocate_heap
  *
  * Description:
@@ -72,7 +72,7 @@ static ubyte sim_heap[SIM_HEAP_SIZE];
  *   are not defined, then this function will be called to
  *   dynamically set aside the heap region.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_allocate_heap(void **heap_start, size_t *heap_size)
 {
diff --git a/arch/sim/src/up_blocktask.c b/arch/sim/src/up_blocktask.c
index ad432fa0216..33056018f0b 100644
--- a/arch/sim/src/up_blocktask.c
+++ b/arch/sim/src/up_blocktask.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_blocktask.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -45,23 +45,23 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_block_task
  *
  * Description:
@@ -79,7 +79,7 @@
  *   task_state: Specifies which waiting task list should be
  *     hold the blocked task TCB.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_block_task(_TCB *tcb, tstate_t task_state)
 {
diff --git a/arch/sim/src/up_createstack.c b/arch/sim/src/up_createstack.c
index c56e7a1a9dd..f0aa8fdf6b1 100644
--- a/arch/sim/src/up_createstack.c
+++ b/arch/sim/src/up_createstack.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_createstack.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -43,23 +43,23 @@
 #include <nuttx/kmalloc.h>
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_create_stack
  *
  * Description:
@@ -79,7 +79,7 @@
  *   stack_size: The requested stack size.  At least this much
  *     must be allocated.
  *
- ************************************************************/
+ ****************************************************************************/
 
 STATUS up_create_stack(_TCB *tcb, size_t stack_size)
 {
diff --git a/arch/sim/src/up_devconsole.c b/arch/sim/src/up_devconsole.c
index 1bb0debdd4c..6bf733f718c 100644
--- a/arch/sim/src/up_devconsole.c
+++ b/arch/sim/src/up_devconsole.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_devconsole.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,43 +31,32 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  *
- ************************************************************/
+ ****************************************************************************/
 
-#if !defined(linux) && !defined(__CYGWIN__)
-# error "Sorry, this will only work with Linux"
-#else
-
-/************************************************************
+/****************************************************************************
  * Included Files
- ************************************************************/
+ ****************************************************************************/
 
 #include <nuttx/config.h>
 #include <sys/types.h>
-
-#include <stdio.h>
-#include <errno.h>
-
 #include <nuttx/fs.h>
 
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Definitions
- ************************************************************/
+ ****************************************************************************/
 
-#define READ   3
-#define WRITE  4
-
-/************************************************************
+/****************************************************************************
  * Private Function Prototypes
- ************************************************************/
+ ****************************************************************************/
 
 static ssize_t devconsole_read(struct file *, char *, size_t);
 static ssize_t devconsole_write(struct file *, const char *, size_t);
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
 static struct file_operations devconsole_fops =
 {
@@ -75,69 +64,26 @@ static struct file_operations devconsole_fops =
   .write	= devconsole_write,
 };
 
-/************************************************************
+/****************************************************************************
  * Private Functions
- ************************************************************/
+ ****************************************************************************/
 
-static inline int up_read(int fd, void* buf, size_t count)
+
+ static ssize_t devconsole_read(struct file *filp, char *buffer, size_t len)
 {
-  uint32 result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (READ), "b" ((uint32)(fd)), "c" ((uint32)(buf)), "d" ((uint32)(count)) \
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_write(int fd, const void* buf, size_t count)
-{
-  uint32 result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (WRITE), "b" ((uint32)(fd)), "c" ((uint32)(buf)), "d" ((uint32)(count)) \
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_check_result(int result)
-{
-  if (result >= (uint32)(-(128 + 1)))
-    {
-      *get_errno_ptr() = -result;
-      result = ERROR;
-    }
-  return result;
-}
-
-static ssize_t devconsole_read(struct file *filp, char *buffer, size_t len)
-{
-  return up_check_result(up_read(1, buffer, len));
+  return up_hostread(buffer, len);
 }
 
 static ssize_t devconsole_write(struct file *filp, const char *buffer, size_t len)
 {
-  return up_check_result(up_write(1, buffer, len));
+  return up_hostwrite(buffer, len);
 }
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
 void up_devconsole(void)
 {
   (void)register_driver("/dev/console", &devconsole_fops, 0666, NULL);
 }
-
-int up_putc(int ch)
-{
-  char b = ch;
-  (void)up_write(1, &b, 1);
-  return ch;
-}
-
-#endif /* linux */
-
diff --git a/arch/sim/src/up_head.c b/arch/sim/src/up_head.c
index e095deb7cea..4f054211f49 100644
--- a/arch/sim/src/up_head.c
+++ b/arch/sim/src/up_head.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_head.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  *
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Included Files
- ************************************************************/
+ ****************************************************************************/
 
 #include <sys/types.h>
 #include <stdio.h>
@@ -45,15 +45,15 @@
 #include <nuttx/init.h>
 #include <nuttx/arch.h>
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
 static jmp_buf sim_abort;
 
-/************************************************************
- * Global Funtions
- ************************************************************/
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
 
 int main(int argc, char **argv, char **envp)
 {
diff --git a/arch/sim/src/up_idle.c b/arch/sim/src/up_idle.c
index 5735540e166..84177f106f1 100644
--- a/arch/sim/src/up_idle.c
+++ b/arch/sim/src/up_idle.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_idle.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,34 +31,34 @@
  * 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 <nuttx/arch.h>
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_idle
  *
  * Description:
@@ -71,7 +71,7 @@
  *   this is where power management operations might be
  *   performed.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_idle(void)
 {
diff --git a/arch/sim/src/up_initialize.c b/arch/sim/src/up_initialize.c
index 82ba215d85c..cb5901ffeac 100644
--- a/arch/sim/src/up_initialize.c
+++ b/arch/sim/src/up_initialize.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_initialize.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -43,23 +43,23 @@
 #include <nuttx/fs.h>
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_initialize
  *
  * Description:
@@ -77,7 +77,7 @@
  *   libraries have been initialized.  OS services and driver
  *   services are available.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_initialize(void)
 {
diff --git a/arch/sim/src/up_initialstate.c b/arch/sim/src/up_initialstate.c
index ec3e50991b8..6a17863f73a 100644
--- a/arch/sim/src/up_initialstate.c
+++ b/arch/sim/src/up_initialstate.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_initialstate.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -43,23 +43,23 @@
 #include <nuttx/arch.h>
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_initial_state
  *
  * Description:
@@ -71,7 +71,7 @@
  *   and/or  stack so that execution will begin at tcb->start
  *   on the next context switch.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_initial_state(_TCB *tcb)
 {
diff --git a/arch/sim/src/up_internal.h b/arch/sim/src/up_internal.h
index fbe5e5e44ce..250bf0e06ee 100644
--- a/arch/sim/src/up_internal.h
+++ b/arch/sim/src/up_internal.h
@@ -107,6 +107,11 @@ extern void up_registerblockdevice(void);
 
 extern char *up_deviceimage(void);
 
+/* up_stdio.c *************************************************************/
+
+extern size_t up_hostread(void *buffer, size_t len);
+extern size_t up_hostwrite(const void *buffer, size_t len);
+
 /* up_tapdev.c ************************************************************/
 
 #ifdef CONFIG_NET 
diff --git a/arch/sim/src/up_interruptcontext.c b/arch/sim/src/up_interruptcontext.c
index ad1eb74d7e1..c9f32c5b84b 100644
--- a/arch/sim/src/up_interruptcontext.c
+++ b/arch/sim/src/up_interruptcontext.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_interruptcontext.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,40 +31,40 @@
  * 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 <nuttx/arch.h>
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_interrupt_context
  *
  * Description:
  *   Return TRUE is we are currently executing in
  *   the interrupt handler context.
- ************************************************************/
+ ****************************************************************************/
 
 boolean up_interrupt_context(void)
 {
diff --git a/arch/sim/src/up_releasepending.c b/arch/sim/src/up_releasepending.c
index 5f25a0db6e7..14601289dd8 100644
--- a/arch/sim/src/up_releasepending.c
+++ b/arch/sim/src/up_releasepending.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_releasepending.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -45,23 +45,23 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_release_pending
  *
  * Description:
@@ -70,7 +70,7 @@
  *   context switch if a new task is placed at the head of
  *   the ready to run list.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_release_pending(void)
 {
diff --git a/arch/sim/src/up_releasestack.c b/arch/sim/src/up_releasestack.c
index 5fc950c6ab9..6c9cd47521b 100644
--- a/arch/sim/src/up_releasestack.c
+++ b/arch/sim/src/up_releasestack.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_releasestack.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -43,30 +43,30 @@
 #include <nuttx/arch.h>
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_release_stack
  *
  * Description:
  *   A task has been stopped. Free all stack
  *   related resources retained int the defunct TCB.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_release_stack(_TCB *dtcb)
 {
diff --git a/arch/sim/src/up_reprioritizertr.c b/arch/sim/src/up_reprioritizertr.c
index f2a2b282873..5f1d2a42cde 100644
--- a/arch/sim/src/up_reprioritizertr.c
+++ b/arch/sim/src/up_reprioritizertr.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_reprioritizertr.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -45,23 +45,23 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_reprioritize_rtr
  *
  * Description:
@@ -79,7 +79,7 @@
  *   tcb: The TCB of the task that has been reprioritized
  *   priority: The new task priority
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_reprioritize_rtr(_TCB *tcb, ubyte priority)
 {
diff --git a/arch/sim/src/up_schedulesigaction.c b/arch/sim/src/up_schedulesigaction.c
index 6e6d13911b3..372458a4345 100644
--- a/arch/sim/src/up_schedulesigaction.c
+++ b/arch/sim/src/up_schedulesigaction.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_schedulesigaction.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -45,23 +45,23 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_schedule_sigaction
  *
  * Description:
@@ -92,7 +92,7 @@
  *       currently executing task -- just call the signal
  *       handler now.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_schedule_sigaction(_TCB *tcb, sig_deliver_t sigdeliver)
 {
diff --git a/arch/sim/src/up_stdio.c b/arch/sim/src/up_stdio.c
new file mode 100644
index 00000000000..cfa5eb225b2
--- /dev/null
+++ b/arch/sim/src/up_stdio.c
@@ -0,0 +1,82 @@
+/****************************************************************************
+ * up_stdio.c
+ *
+ *   Copyright (C) 2007, 2008 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 <stdio.h>
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+size_t up_hostread(void *buffer, size_t len)
+{
+  /* Just map to the host fread() */
+
+  return fread(buffer, 1, len, stdout);
+}
+
+size_t up_hostwrite(const void *buffer, size_t len)
+{
+  /* Just map to the host fwrite() */
+
+  return fwrite(buffer, 1, len, stdout);
+}
+
+int up_putc(int ch)
+{
+  /* Just map to the host fputc routine */
+
+  return fputc(ch, stdout);
+}
+
diff --git a/arch/sim/src/up_tapdev.c b/arch/sim/src/up_tapdev.c
index 7e9809e5cbf..0867117509f 100644
--- a/arch/sim/src/up_tapdev.c
+++ b/arch/sim/src/up_tapdev.c
@@ -2,7 +2,7 @@
 /****************************************************************************
  * up_tapdev.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Based on code from uIP which also has a BSD-like license:
@@ -84,13 +84,6 @@ extern int lib_rawprintf(const char *format, ...);
 #  define UIP_IPADDR3   0
 #endif
 
-#define READ            3
-#define WRITE           4
-#define OPEN            5
-#define IOCTL           54
-#define SELECT          82
-#define SOCKETCALL      102
-
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -123,93 +116,6 @@ static int gtapdevfd;
  * Private Functions
  ****************************************************************************/
 
-/* This is REALLY awkward.. we need to compile using the system header files,
- * but we can't use any of the libc calls because all of the symbols are
- * defined for NuttX (read, write, etc)!  So we do hand rolled syscalls
- * to get to the Linux functions.
- */
-
-static inline int up_open(const char *filename, int flags, int mode)
-{
-  int result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (OPEN), "b" ((int)(filename)), "c" ((int)(flags)), "d" ((int)(mode)) \
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_socketcall(int call, unsigned long *args)
-{
-  int result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (SOCKETCALL), "b" (call), "c" ((int)args)	\
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_socket(int domain, int type, int protocol)
-{
-  unsigned long args[3];
-  args[0] = domain;
-  args[1] = type;
-  args[2] = protocol;
-  return up_socketcall(SYS_SOCKET, args);  
-}
-
-static inline int up_read(int fd, void* buf, size_t count)
-{
-  ssize_t result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (READ), "b" ((int)(fd)), "c" ((int)(buf)), "d" ((int)(count)) \
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_write(int fd, const void* buf, size_t count)
-{
-  ssize_t result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (WRITE), "b" ((int)(fd)), "c" ((int)(buf)), "d" ((int)(count)) \
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_ioctl(int fd, unsigned int cmd, unsigned long arg)
-{
-  ssize_t result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (IOCTL), "b" ((int)(fd)), "c" ((int)(cmd)), "d" ((long)(arg)) \
-                    : "memory");
-
-  return (int)result;
-}
-
-static inline int up_select(struct sel_arg_struct *arg)
-{
-  ssize_t result;
-
-  __asm__ volatile ("int $0x80" \
-                    : "=a" (result) \
-                    : "0" (SELECT),"b" ((struct sel_arg_struct *)(arg))
-                    : "memory");
-
-  return (int)result;
-}
-
 #ifdef TAPDEV_DEBUG
 static inline void dump_ethhdr(const char *msg, unsigned char *buf, int buflen)
 {
@@ -246,7 +152,7 @@ void tapdev_init(void)
 
   /* Open the tap device */
 
-  gtapdevfd = up_open(DEVTAP, O_RDWR, 0644);
+  gtapdevfd = open(DEVTAP, O_RDWR, 0644);
   if (gtapdevfd < 0)
     {
       lib_rawprintf("TAPDEV: open failed: %d\n", -gtapdevfd );
@@ -257,7 +163,7 @@ void tapdev_init(void)
 
   memset(&ifr, 0, sizeof(ifr));
   ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
-  ret = up_ioctl(gtapdevfd, TUNSETIFF, (unsigned long) &ifr);
+  ret = ioctl(gtapdevfd, TUNSETIFF, (unsigned long) &ifr);
   if (ret < 0)
     {
       lib_rawprintf("TAPDEV: ioctl failed: %d\n", -ret );
@@ -278,7 +184,7 @@ int tapdev_getmacaddr(unsigned char *macaddr)
     {
       /* Get a socket (only so that we get access to the INET subsystem) */
 
-      int sockfd = up_socket(PF_INET, SOCK_DGRAM, 0);
+      int sockfd = socket(PF_INET, SOCK_DGRAM, 0);
       if (sockfd >= 0)
         {
           struct ifreq req;
@@ -290,7 +196,7 @@ int tapdev_getmacaddr(unsigned char *macaddr)
 
           /* Perform the ioctl to get the MAC address */
 
-          ret = up_ioctl(sockfd, SIOCGIFHWADDR, (unsigned long)&req);
+          ret = ioctl(sockfd, SIOCGIFHWADDR, (unsigned long)&req);
           if (!ret)
             {
               /* Return the MAC address */
@@ -304,7 +210,6 @@ int tapdev_getmacaddr(unsigned char *macaddr)
 
 unsigned int tapdev_read(unsigned char *buf, unsigned int buflen)
 {
-  struct sel_arg_struct arg;
   fd_set                fdset;
   struct timeval        tv;
   int                   ret;
@@ -324,19 +229,13 @@ unsigned int tapdev_read(unsigned char *buf, unsigned int buflen)
   FD_ZERO(&fdset);
   FD_SET(gtapdevfd, &fdset);
 
-  arg.n    = gtapdevfd + 1;
-  arg.inp  = &fdset;
-  arg.outp = NULL;
-  arg.exp  = NULL;
-  arg.tvp  = &tv;
-
-  ret = up_select(&arg);
+  ret = select(gtapdevfd + 1, &fdset, NULL, NULL, &tv);
   if(ret == 0)
     {
       return 0;
     }
 
-  ret = up_read(gtapdevfd, buf, buflen);
+  ret = read(gtapdevfd, buf, buflen);
   if (ret < 0)
     {
       lib_rawprintf("TAPDEV: read failed: %d\n", -ret);
@@ -361,7 +260,7 @@ void tapdev_send(unsigned char *buf, unsigned int buflen)
     }
 #endif
 
-  ret = up_write(gtapdevfd, buf, buflen);
+  ret = write(gtapdevfd, buf, buflen);
   if (ret < 0)
     {
       lib_rawprintf("TAPDEV: write failed: %d", -ret);
diff --git a/arch/sim/src/up_unblocktask.c b/arch/sim/src/up_unblocktask.c
index ba5f5987d35..f13f7fb0f35 100644
--- a/arch/sim/src/up_unblocktask.c
+++ b/arch/sim/src/up_unblocktask.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_unblocktask.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -46,23 +46,23 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_unblock_task
  *
  * Description:
@@ -76,7 +76,7 @@
  *     the ready-to-run list and, if it is the highest priority
  *     ready to run taks, executed.
  *
- ************************************************************/
+ ****************************************************************************/
 
 void up_unblock_task(_TCB *tcb)
 {
diff --git a/arch/sim/src/up_usestack.c b/arch/sim/src/up_usestack.c
index d8964b64421..e28cac3129f 100644
--- a/arch/sim/src/up_usestack.c
+++ b/arch/sim/src/up_usestack.c
@@ -1,7 +1,7 @@
-/************************************************************
+/****************************************************************************
  * up_usestack.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -14,7 +14,7 @@
  *    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
+ * 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.
  *
@@ -31,11 +31,11 @@
  * 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>
@@ -44,23 +44,23 @@
 #include "os_internal.h"
 #include "up_internal.h"
 
-/************************************************************
+/****************************************************************************
  * Private Definitions
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Private Data
- ************************************************************/
+ ****************************************************************************/
 
-/************************************************************
- * Private Funtions
- ************************************************************/
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
 
-/************************************************************
- * Public Funtions
- ************************************************************/
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
 
-/************************************************************
+/****************************************************************************
  * Name: up_use_stack
  *
  * Description:
@@ -79,7 +79,7 @@
  *   tcb: The TCB of new task
  *   stack_size: The allocated stack size.
  *
- ************************************************************/
+ ****************************************************************************/
 
 STATUS up_use_stack(_TCB *tcb, void *stack, size_t stack_size)
 {