diff --git a/configs/sim/nx/Make.defs b/configs/sim/nx/Make.defs
new file mode 100644
index 0000000000000000000000000000000000000000..936e161a2f1ade5fd777f0931c63634d81f384fe
--- /dev/null
+++ b/configs/sim/nx/Make.defs
@@ -0,0 +1,110 @@
+############################################################################
+# configs/sim/nx/Make.defs
+#
+#   Copyright (C) 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.
+#
+############################################################################
+
+include ${TOPDIR}/.config
+
+HOSTOS			= ${shell uname -o}
+
+ifeq ($(CONFIG_DEBUG),y)
+  ARCHOPTIMIZATION	= -g
+else
+  ARCHOPTIMIZATION	= -O2
+endif
+
+ARCHCPUFLAGS		= -fno-builtin
+ARCHPICFLAGS		= -fpic
+ARCHWARNINGS		= -Wall -Wstrict-prototypes -Wshadow
+ARCHDEFINES		=
+ARCHINCLUDES		= -I. -isystem $(TOPDIR)/include
+ARCHSCRIPT		=
+
+CROSSDEV		=
+CC			= $(CROSSDEV)gcc
+CPP			= $(CROSSDEV)gcc -E
+LD			= $(CROSSDEV)ld
+AR			= $(CROSSDEV)ar rcs
+NM			= $(CROSSDEV)nm
+OBJCOPY			= $(CROSSDEV)objcopy
+OBJDUMP			= $(CROSSDEV)objdump
+
+CFLAGS			= $(ARCHWARNINGS) $(ARCHOPTIMIZATION) \
+			  $(ARCHCPUFLAGS) $(ARCHINCLUDES) $(ARCHDEFINES) -pipe
+CPPFLAGS		= $(ARCHINCLUDES) $(ARCHDEFINES)
+AFLAGS			= $(CFLAGS) -D__ASSEMBLY__
+
+OBJEXT			= .o
+LIBEXT			= .a
+
+ifeq ($(HOSTOS),Cygwin)
+  EXEEXT		= .exe
+else
+  EXEEXT		=
+endif
+
+ifeq ("${CONFIG_DEBUG}","y")
+  LDFLAGS		+= -g
+endif
+
+define PREPROCESS
+	@echo "CPP: $1->$2"
+	@$(CPP) $(CPPFLAGS) $1 -o $2
+endef
+
+define COMPILE
+	@echo "CC: $1"
+	@$(CC) -c $(CFLAGS) $1 -o $2
+endef
+
+define ASSEMBLE
+	@echo "AS: $1"
+	@$(CC) -c $(AFLAGS) $1 -o $2
+endef
+
+define ARCHIVE
+	echo "AR: $2"; \
+	$(AR) $1 $2 || { echo "$(AR) $1 $2 FAILED!" ; exit 1 ; }
+endef
+
+define CLEAN
+	@rm -f *.o *.a
+endef
+
+MKDEP			= $(TOPDIR)/tools/mkdeps.sh
+
+HOSTCC			= gcc
+HOSTINCLUDES		= -I.
+HOSTCFLAGS		= $(ARCHWARNINGS) $(ARCHOPTIMIZATION) \
+			  $(ARCHCPUFLAGS) $(HOSTINCLUDES) $(ARCHDEFINES) -pipe
+HOSTLDFLAGS		=
diff --git a/configs/sim/nx/defconfig b/configs/sim/nx/defconfig
new file mode 100644
index 0000000000000000000000000000000000000000..914686422de786ac9ff17162f241e009b38efafe
--- /dev/null
+++ b/configs/sim/nx/defconfig
@@ -0,0 +1,450 @@
+############################################################################
+# sim/nx/defconfig
+#
+#   Copyright (C) 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.
+#
+############################################################################
+#
+# Architecture selection
+#
+# CONFIG_ARCH - identifies the arch subdirectory and, hence, the
+#   processor architecture.
+# CONFIG_ARCH_name - for use in C code.  This identifies the particular
+#   processor architecture (CONFIG_ARCH_SIM).
+# CONFIG_ARCH_BOARD - identifies the configs subdirectory and, hence,
+#   the board that supports the particular chip or SoC.
+# CONFIG_ARCH_BOARD_name - for use in C code
+# CONFIG_ENDIAN_BIG - define if big endian (default is little endian)
+#
+CONFIG_ARCH=sim
+CONFIG_ARCH_SIM=y
+CONFIG_ARCH_BOARD=sim
+CONFIG_ARCH_BOARD_SIM=y
+
+#
+# General OS setup
+#
+# CONFIG_EXAMPLE - identifies the subdirectory in examples
+#   that will be used in the build
+# CONFIG_DEBUG - enables built-in debug options
+# CONFIG_DEBUG_VERBOSE - enables verbose debug output
+# CONFIG_MM_REGIONS - If the architecture includes multiple
+#   regions of memory to allocate from, this specifies the
+#   number of memory regions that the memory manager must
+#   handle and enables the API mm_addregion(start, end);
+# CONFIG_ARCH_LOWPUTC - architecture supports low-level, boot
+#   time console output
+# CONFIG_TICKS_PER_MSEC - The default system timer is 100Hz
+#   or TICKS_PER_MSEC=10.  This setting may be defined to
+#   inform NuttX that the processor hardware is providing
+#   system timer interrupts at some interrupt interval other
+#   than 10 msec.
+# CONFIG_RR_INTERVAL - The round robin timeslice will be set
+#   this number of milliseconds;  Round robin scheduling can
+#   be disabled by setting this value to zero.
+# CONFIG_SCHED_INSTRUMENTATION - enables instrumentation in 
+#   scheduler to monitor system performance
+# CONFIG_TASK_NAME_SIZE - Spcifies that maximum size of a
+#   task name to save in the TCB.  Useful if scheduler
+#   instrumentation is selected.  Set to zero to disable.
+# CONFIG_JULIAN_TIME - Enables Julian time conversions
+# CONFIG_START_YEAR, CONFIG_START_MONTH, CONFIG_START_DAY -
+#   Used to initialize the internal time logic.
+# CONFIG_DEV_CONSOLE - Set if architecture-specific logic
+#   provides /dev/console.  Enables stdout, stderr, stdin.
+# CONFIG_DEV_LOWCONSOLE - Use the simple, low-level serial console
+#   driver (minimul support)
+#
+CONFIG_EXAMPLE=nx
+CONFIG_DEBUG=y
+CONFIG_DEBUG_VERBOSE=y
+CONFIG_MM_REGIONS=1
+CONFIG_ARCH_LOWPUTC=y
+CONFIG_RR_INTERVAL=0
+CONFIG_SCHED_INSTRUMENTATION=n
+CONFIG_TASK_NAME_SIZE=32
+CONFIG_START_YEAR=2008
+CONFIG_START_MONTH=11
+CONFIG_START_DAY=28
+CONFIG_JULIAN_TIME=n
+CONFIG_DEV_CONSOLE=y
+CONFIG_DEV_LOWCONSOLE=n
+
+#
+# The following can be used to disable categories of
+# APIs supported by the OS.  If the compiler supports
+# weak functions, then it should not be necessary to
+# disable functions unless you want to restrict usage
+# of those APIs.
+#
+# There are certain dependency relationships in these
+# features.
+#
+# o mq_notify logic depends on signals to awaken tasks
+#   waiting for queues to become full or empty.
+# o pthread_condtimedwait() depends on signals to wake
+#   up waiting tasks.
+#
+CONFIG_DISABLE_CLOCK=n
+CONFIG_DISABLE_POSIX_TIMERS=y
+CONFIG_DISABLE_PTHREAD=y
+CONFIG_DISABLE_SIGNALS=y
+CONFIG_DISABLE_MQUEUE=y
+CONFIG_DISABLE_MOUNTPOINT=y
+CONFIG_DISABLE_ENVIRON=y
+CONFIG_DISABLE_POLL=y
+
+#
+# Misc libc settings
+#
+# CONFIG_NOPRINTF_FIELDWIDTH - sprintf-related logic is a
+#   little smaller if we do not support fieldwidthes
+#
+CONFIG_NOPRINTF_FIELDWIDTH=n
+
+#
+# Allow for architecture optimized implementations
+#
+# The architecture can provide optimized versions of the
+# following to improve sysem performance
+#
+CONFIG_ARCH_MEMCPY=n
+CONFIG_ARCH_MEMCMP=n
+CONFIG_ARCH_MEMMOVE=n
+CONFIG_ARCH_MEMSET=n
+CONFIG_ARCH_STRCMP=n
+CONFIG_ARCH_STRCPY=n
+CONFIG_ARCH_STRNCPY=n
+CONFIG_ARCH_STRLEN=n
+CONFIG_ARCH_BZERO=n
+CONFIG_ARCH_KMALLOC=n
+CONFIG_ARCH_KZMALLOC=n
+CONFIG_ARCH_KFREE=n
+
+#
+# General build options
+#
+# CONFIG_RRLOAD_BINARY - make the rrload binary format used with
+#   BSPs from www.ridgerun.com using the tools/mkimage.sh script
+# CONFIG_INTELHEX_BINARY - make the Intel HEX binary format
+#   used with many different loaders using the GNU objcopy program
+#   Should not be selected if you are not using the GNU toolchain.
+# CONFIG_RAW_BINARY - make a raw binary format file used with many
+#   different loaders using the GNU objcopy program.  This option
+#   should not be selected if you are not using the GNU toolchain.
+# CONFIG_HAVE_LIBM - toolchain supports libm.a
+#
+CONFIG_RRLOAD_BINARY=n
+CONFIG_INTELHEX_BINARY=n
+CONFIG_RAW_BINARY=n
+CONFIG_HAVE_LIBM=y
+
+#
+# Sizes of configurable things (0 disables)
+#
+# CONFIG_MAX_TASKS - The maximum number of simultaneously
+#   active tasks. This value must be a power of two.
+# CONFIG_MAX_TASK_ARGS - This controls the maximum number of
+#   of parameters that a task may receive (i.e., maxmum value
+#   of 'argc')
+# CONFIG_NPTHREAD_KEYS - The number of items of thread-
+#   specific data that can be retained
+# CONFIG_NFILE_DESCRIPTORS - The maximum number of file
+#   descriptors (one for each open)
+# CONFIG_NFILE_STREAMS - The maximum number of streams that
+#   can be fopen'ed
+# CONFIG_NAME_MAX - The maximum size of a file name.
+# CONFIG_STDIO_BUFFER_SIZE - Size of the buffer to allocate
+#   on fopen. (Only if CONFIG_NFILE_STREAMS > 0)
+# CONFIG_NUNGET_CHARS - Number of characters that can be
+#   buffered by ungetc() (Only if CONFIG_NFILE_STREAMS > 0)
+# CONFIG_PREALLOC_MQ_MSGS - The number of pre-allocated message
+#   structures.  The system manages a pool of preallocated
+#   message structures to minimize dynamic allocations
+# CONFIG_MQ_MAXMSGSIZE - Message structures are allocated with
+#   a fixed payload size given by this settin (does not include
+#   other message structure overhead.
+# CONFIG_MAX_WDOGPARMS - Maximum number of parameters that
+#   can be passed to a watchdog handler
+# CONFIG_PREALLOC_WDOGS - The number of pre-allocated watchdog
+#   structures.  The system manages a pool of preallocated
+#   watchdog structures to minimize dynamic allocations
+# CONFIG_PREALLOC_TIMERS - The number of pre-allocated POSIX
+#   timer structures.  The system manages a pool of preallocated
+#   timer structures to minimize dynamic allocations.  Set to
+#   zero for all dynamic allocations.
+#
+CONFIG_MAX_TASKS=16
+CONFIG_MAX_TASK_ARGS=4
+CONFIG_NPTHREAD_KEYS=4
+CONFIG_NFILE_DESCRIPTORS=16
+CONFIG_NFILE_STREAMS=16
+CONFIG_NAME_MAX=32
+CONFIG_STDIO_BUFFER_SIZE=1024
+CONFIG_NUNGET_CHARS=2
+CONFIG_PREALLOC_MQ_MSGS=32
+CONFIG_MQ_MAXMSGSIZE=32
+CONFIG_MAX_WDOGPARMS=4
+CONFIG_PREALLOC_WDOGS=32
+CONFIG_PREALLOC_TIMERS=8
+
+#
+# FAT filesystem configuration
+# CONFIG_FS_FAT - Enable FAT filesystem support
+# CONFIG_FAT_SECTORSIZE - Max supported sector size
+# CONFIG_FS_ROMFS - Enable ROMFS filesystem support
+CONFIG_FS_FAT=n
+CONFIG_FS_ROMFS=n
+
+#
+# TCP/IP and UDP support via uIP
+# CONFIG_NET - Enable or disable all network features
+# CONFIG_NET_IPv6 - Build in support for IPv6
+# CONFIG_NSOCKET_DESCRIPTORS - Maximum number of socket descriptors per task/thread.
+# CONFIG_NET_SOCKOPTS - Enable or disable support for socket options
+# CONFIG_NET_BUFSIZE - uIP buffer size
+# CONFIG_NET_TCP - TCP support on or off
+# CONFIG_NET_TCP_CONNS - Maximum number of TCP connections (all tasks)
+# CONFIG_NET_TCP_READAHEAD_BUFSIZE - Size of TCP read-ahead buffers
+# CONFIG_NET_NTCP_READAHEAD_BUFFERS - Number of TCP read-ahead buffers (may be zero)
+# CONFIG_NET_TCPBACKLOG - Incoming connections pend in a backlog until
+#   accept() is called. The size of the backlog is selected when listen() is called.
+# CONFIG_NET_MAX_LISTENPORTS - Maximum number of listening TCP ports (all tasks)
+# CONFIG_NET_UDP - UDP support on or off
+# CONFIG_NET_UDP_CHECKSUMS - UDP checksums on or off
+# CONFIG_NET_UDP_CONNS - The maximum amount of concurrent UDP connections
+# CONFIG_NET_ICMP - ICMP ping response support on or off
+# CONFIG_NET_ICMP_PING - ICMP ping request support on or off
+# CONFIG_NET_PINGADDRCONF - Use "ping" packet for setting IP address
+# CONFIG_NET_STATISTICS - uIP statistics on or off
+# CONFIG_NET_RECEIVE_WINDOW - The size of the advertised receiver's window
+# CONFIG_NET_ARPTAB_SIZE - The size of the ARP table
+# CONFIG_NET_BROADCAST - Broadcast support
+# CONFIG_NET_LLH_LEN - The link level header length
+# CONFIG_NET_FWCACHE_SIZE - number of packets to remember when looking for duplicates
+CONFIG_NET=n
+CONFIG_NET_IPv6=n
+CONFIG_NSOCKET_DESCRIPTORS=0
+CONFIG_NET_SOCKOPTS=y
+CONFIG_NET_BUFSIZE=420
+CONFIG_NET_TCP=n
+CONFIG_NET_TCP_CONNS=40
+CONFIG_NET_MAX_LISTENPORTS=40
+CONFIG_NET_UDP=n
+CONFIG_NET_UDP_CHECKSUMS=y
+#CONFIG_NET_UDP_CONNS=10
+CONFIG_NET_ICMP=n
+CONFIG_NET_ICMP_PING=n
+#CONFIG_NET_PINGADDRCONF=0
+CONFIG_NET_STATISTICS=y
+#CONFIG_NET_RECEIVE_WINDOW=
+#CONFIG_NET_ARPTAB_SIZE=8
+CONFIG_NET_BROADCAST=n
+#CONFIG_NET_LLH_LEN=14
+#CONFIG_NET_FWCACHE_SIZE=2
+
+#
+# UIP Network Utilities
+# CONFIG_NET_DHCP_LIGHT - Reduces size of DHCP
+# CONFIG_NET_RESOLV_ENTRIES - Number of resolver entries
+CONFIG_NET_DHCP_LIGHT=n
+CONFIG_NET_RESOLV_ENTRIES=4
+
+#
+# Graphics related configuration settings
+#
+# CONFIG_NXGRAPHICS
+#   Enables overall support for graphics library and NX
+# CONFIG_NX_MULTIUSER
+#   Configures NX in multi-user mode
+# CONFIG_NX_NPLANES
+#   Some YUV color formats requires support for multiple planes,
+#   one for each color component.  Unless you have such special
+#   hardware, this value should be undefined or set to 1
+# CONFIG_NXGLIB_DISABLE_1BPP, CONFIG_NXGLIB_DISABLE_2BPP,
+# CONFIG_NXGLIB_DISABLE_4BPP, CONFIG_NXGLIB_DISABLE_8BPP,
+# CONFIG_NXGLIB_DISABLE_16BPP, CONFIG_NXGLIB_DISABLE_24BPP, and
+# CONFIG_NXGLIB_DISABLE_32BPP
+#   NX supports a variety of pixel depths.  You can save some
+#   memory by disabling support for unused color depths.
+# CONFIG_NXGL_PACKEDMSFIRST
+#   If a pixel depth of less than 8-bits is used, then NX needs
+#   to know if the pixels pack from the MS to LS or from LS to MS
+# CONFIG_NX_MOUSE
+#   Build in support for mouse input
+# CONFIG_NX_KBD
+#   Build in support of keypad/keyboard input
+#
+# NX Multi-user only options:
+#
+# CONFIG_NX_BLOCKING
+#   Open the client message queues in blocking mode.  In this case,
+#   nx_eventhandler() will never return.
+# CONFIG_NX_MXSERVERMSGS and CONFIG_NX_MXCLIENTMSGS
+#   Specifies the maximum number of messages that can fit in
+#   the message queues.  No additional resources are allocated, but
+#   this can be set to prevent flooding of the client or server with
+#   too many messages (CONFIG_PREALLOC_MQ_MSGS controls how many
+#   messages are pre-allocated).
+CONFIG_NXGRAPHICS=y
+CONFIG_NX_MULTIUSER=n
+CONFIG_NX_NPLANES=1
+CONFIG_NXGLIB_DISABLE_1BPP=n
+CONFIG_NXGLIB_DISABLE_2BPP=n
+CONFIG_NXGLIB_DISABLE_4BPP=n
+CONFIG_NXGLIB_DISABLE_8BPP=y
+CONFIG_NXGLIB_DISABLE_16BPP=n
+CONFIG_NXGLIB_DISABLE_24BPP=n
+CONFIG_NXGLIB_DISABLE_32BPP=n
+CONFIG_NXGL_PACKEDMSFIRST=n
+CONFIG_NX_MOUSE=n
+CONFIG_NX_KBD=n
+CONFIG_NX_BLOCKING=n
+CONFIG_NX_MXSERVERMSGS=32
+CONFIG_NX_MXCLIENTMSGS=16
+
+#
+# Settings for examples/uip
+CONFIG_EXAMPLE_UIP_IPADDR=(192<<24|168<<16|0<<8|128)
+CONFIG_EXAMPLE_UIP_DRIPADDR=(192<<24|168<<16|0<<8|1)
+CONFIG_EXAMPLE_UIP_NETMASK=(255<<24|255<<16|255<<8|0)
+CONFIG_EXAMPLE_UIP_SMTP=n
+CONFIG_EXAMPLE_UIP_TELNETD=n
+CONFIG_EXAMPLE_UIP_WEBSERVER=y
+CONFIG_EXAMPLE_UIP_DHCPC=n
+CONFIG_EXAMPLE_UIP_WEBCLIENT=n
+
+#
+# Settings for examples/nettest
+CONFIG_EXAMPLE_NETTEST_SERVER=n
+CONFIG_EXAMPLE_NETTEST_PERFORMANCE=n
+CONFIG_EXAMPLE_NETTEST_NOMAC=n
+CONFIG_EXAMPLE_NETTEST_IPADDR=(192<<24|168<<16|0<<8|128)
+CONFIG_EXAMPLE_NETTEST_DRIPADDR=(192<<24|168<<16|0<<8|1)
+CONFIG_EXAMPLE_NETTEST_NETMASK=(255<<24|255<<16|255<<8|0)
+CONFIG_EXAMPLE_NETTEST_CLIENTIP=(192<<24|168<<16|0<<8|106)
+
+#
+# Settings for examples/ostest
+CONFIG_EXAMPLES_OSTEST_LOOPS=100
+CONFIG_EXAMPLES_OSTEST_STACKSIZE=8192
+
+#
+# Settings for examples/nsh
+#
+# CONFIG_EXAMPLES_NSH_FILEIOSIZE - Size of a static I/O buffer
+# CONFIG_EXAMPLES_NSH_STRERROR - Use strerror(errno)
+# CONFIG_EXAMPLES_NSH_LINELEN - Maximum length of one command line
+# CONFIG_EXAMPLES_NSH_STACKSIZE - Stack size to use for new threads.
+# CONFIG_EXAMPLES_NSH_NESTDEPTH - Max number of nested if-then[-else]-fi
+# CONFIG_EXAMPLES_NSH_DISABLESCRIPT - Disable scripting support
+# CONFIG_EXAMPLES_NSH_DISABLEBG - Disable background commands
+# CONFIG_EXAMPLES_NSH_ROMFSETC - Use startup script in /etc
+# CONFIG_EXAMPLES_NSH_CONSOLE - Use serial console front end
+# CONFIG_EXAMPLES_NSH_TELNET - Use telnetd console front end
+#
+# If CONFIG_EXAMPLES_NSH_TELNET is selected:
+# CONFIG_EXAMPLES_NSH_IOBUFFER_SIZE -- Telnetd I/O buffer size
+# CONFIG_EXAMPLES_NSH_DHCPC - Obtain address using DHCP
+# CONFIG_EXAMPLES_NSH_IPADDR - Provides static IP address
+# CONFIG_EXAMPLES_NSH_DRIPADDR - Provides static router IP address
+# CONFIG_EXAMPLES_NSH_NETMASK - Provides static network mask
+# CONFIG_EXAMPLES_NSH_NOMAC - Use a bogus MAC address
+#
+# If CONFIG_EXAMPLES_NSH_ROMFSETC is selected:
+# CONFIG_EXAMPLES_NSH_ROMFSMOUNTPT - ROMFS mountpoint
+# CONFIG_EXAMPLES_NSH_INITSCRIPT - Relative path to init script
+# CONFIG_EXAMPLES_NSH_ROMFSDEVNO - ROMFS RAM device minor
+# CONFIG_EXAMPLES_NSH_ROMFSSECTSIZE - ROMF sector size
+# CONFIG_EXAMPLES_NSH_FATDEVNO - FAT FS RAM device minor
+# CONFIG_EXAMPLES_NSH_FATSECTSIZE - FAT FS sector size
+# CONFIG_EXAMPLES_NSH_FATNSECTORS - FAT FS number of sectors
+# CONFIG_EXAMPLES_NSH_FATMOUNTPT - FAT FS mountpoint
+CONFIG_EXAMPLES_NSH_FILEIOSIZE=1024
+CONFIG_EXAMPLES_NSH_STRERROR=n
+CONFIG_EXAMPLES_NSH_LINELEN=80
+CONFIG_EXAMPLES_NSH_STACKSIZE=4096
+CONFIG_EXAMPLES_NSH_NESTDEPTH=3
+CONFIG_EXAMPLES_NSH_DISABLESCRIPT=n
+CONFIG_EXAMPLES_NSH_DISABLEBG=n
+CONFIG_EXAMPLES_NSH_ROMFSETC=y
+CONFIG_EXAMPLES_NSH_CONSOLE=y
+CONFIG_EXAMPLES_NSH_TELNET=n
+CONFIG_EXAMPLES_NSH_IOBUFFER_SIZE=512
+CONFIG_EXAMPLES_NSH_DHCPC=n
+CONFIG_EXAMPLES_NSH_NOMAC=n
+CONFIG_EXAMPLES_NSH_IPADDR=(10<<24|0<<16|0<<8|2)
+CONFIG_EXAMPLES_NSH_DRIPADDR=(10<<24|0<<16|0<<8|1)
+CONFIG_EXAMPLES_NSH_NETMASK=(255<<24|255<<16|255<<8|0)
+CONFIG_EXAMPLES_NSH_ROMFSMOUNTPT="/etc"
+CONFIG_EXAMPLES_NSH_INITSCRIPT="init.d/rcS"
+CONFIG_EXAMPLES_NSH_ROMFSDEVNO=1
+CONFIG_EXAMPLES_NSH_ROMFSSECTSIZE=64
+CONFIG_EXAMPLES_NSH_FATDEVNO=2
+CONFIG_EXAMPLES_NSH_FATSECTSIZE=512
+CONFIG_EXAMPLES_NSH_FATNSECTORS=1024
+CONFIG_EXAMPLES_NSH_FATMOUNTPT=/tmp
+
+#
+# Settings for examples/mount
+CONFIG_EXAMPLES_MOUNT_DEVNAME="/dev/ram0"
+#CONFIG_EXAMPLES_MOUNT_NSECTORS=2048
+#CONFIG_EXAMPLES_MOUNT_SECTORSIZE=512
+#CONFIG_EXAMPLES_MOUNT_RAMDEVNO=1
+
+#
+# Stack and heap information
+#
+# CONFIG_BOOT_FROM_FLASH - Some configurations support XIP
+#   operation from FLASH.
+# CONFIG_CUSTOM_STACK - The up_ implementation will handle
+#   all stack operations outside of the nuttx model.
+# CONFIG_STACK_POINTER - The initial stack pointer
+# CONFIG_IDLETHREAD_STACKSIZE - The size of the initial stack.
+#  This is the thread that (1) performs the inital boot of the system up
+#  to the point where user_start() is spawned, and (2) there after is the
+#  IDLE thread that executes only when there is no other thread ready to
+#  run.
+# CONFIG_USERMAIN_STACKSIZE - The size of the stack to allocate
+#  for the main user thread that begins at the user_start() entry point.
+# CONFIG_PTHREAD_STACK_MIN - Minimum pthread stack size
+# CONFIG_PTHREAD_STACK_DEFAULT - Default pthread stack size
+# CONFIG_HEAP_BASE - The beginning of the heap
+# CONFIG_HEAP_SIZE - The size of the heap
+#
+CONFIG_BOOT_FROM_FLASH=n
+CONFIG_CUSTOM_STACK=n
+CONFIG_IDLETHREAD_STACKSIZE=4096
+CONFIG_USERMAIN_STACKSIZE=4096
+CONFIG_PTHREAD_STACK_MIN=256
+CONFIG_PTHREAD_STACK_DEFAULT=8192
+CONFIG_HEAP_BASE=
+CONFIG_HEAP_SIZE=
diff --git a/configs/sim/nx/setenv.sh b/configs/sim/nx/setenv.sh
new file mode 100755
index 0000000000000000000000000000000000000000..6a5a7e6c098820c2432be66ffa7bba8d80da9c8d
--- /dev/null
+++ b/configs/sim/nx/setenv.sh
@@ -0,0 +1,45 @@
+#!/bin/bash
+# sim/nx/setenv.sh
+#
+#   Copyright (C) 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.
+#
+
+if [ "$(basename $0)" = "setenv.sh" ] ; then
+  echo "You must source this script, not run it!" 1>&2
+  exit 1
+fi
+
+if [ -z ${PATH_ORIG} ]; then export PATH_ORIG=${PATH}; fi
+
+#export NUTTX_BIN=
+#export PATH=${NUTTX_BIN}:/sbin:/usr/sbin:${PATH_ORIG}
+
+echo "PATH : ${PATH}"