Add graphic device initialize logic (incomplete)

15 files changed, 1121 insertions, 78 deletions

diff --git a/apps/graphics/traveler/Kconfig b/apps/graphics/traveler/Kconfig
index e938ec742..851ab4ca7 100644
--- a/apps/graphics/traveler/Kconfig
+++ b/apps/graphics/traveler/Kconfig
@@ -5,10 +5,22 @@
 
 if GRAPHICS_TRAVELER
 
+choice
+	prompt "Color format"
+	default GRAPHICS_TRAVELER_RGB16_565
+
+config GRAPHICS_TRAVELER_RGB16_565
+	bool "RGB16 565"
+
+config GRAPHICS_TRAVELER_RGB32_888
+	bool "RGB32 888 (no transparency)"
+
+endchoice # Color format
+
 config GRAPHICS_TRAVELER_PERFMON
-	bool "Performance monitor game"
+	bool "Performance monitor"
 	default y
-	depends on NX && FS_READABLE && !NX_LCDDRIVER
+	depends on FS_READABLE
 	---help---
 		Enable or disable performance monitoring instrumentation and output.
 
diff --git a/apps/graphics/traveler/Makefile b/apps/graphics/traveler/Makefile
index 75d48566f..e04bf51c3 100644
--- a/apps/graphics/traveler/Makefile
+++ b/apps/graphics/traveler/Makefile
@@ -46,9 +46,16 @@ STACKSIZE = 2048
 # Hello, World! Example
 
 ASRCS =
-CSRCS =
+CSRCS = trv_mem.c trv_graphics.c
 MAINSRC = trv_main.c
 
+ifeq ($(CONFIG_NX),y)
+CSRCS += trv_nxbkgd.c
+ifeq ($(CONFIG_NX),y)
+CSRCS += trv_nxserver.c
+endif
+endif
+
 AOBJS = $(ASRCS:.S=$(OBJEXT))
 COBJS = $(CSRCS:.c=$(OBJEXT))
 MAINOBJ = $(MAINSRC:.c=$(OBJEXT))
diff --git a/apps/graphics/traveler/include/trv_color.h b/apps/graphics/traveler/include/trv_color.h
index 04e9d1523..0a2cf78bb 100644
--- a/apps/graphics/traveler/include/trv_color.h
+++ b/apps/graphics/traveler/include/trv_color.h
@@ -71,7 +71,7 @@ struct trv_color_lum_s
  ****************************************************************************/
 
 bool trv_color_allocate(FAR struct trv_palette_s *pinfo);
-void trv_color_endmapping(void);
+void trv_color_free(FAR struct trv_palette_s *pinfo);
 trv_pixel_t trv_color_rgb2pixel(FAR struct trv_color_rgb_s *pixel);
 void trv_color_pixel2lum(trv_pixel_t pixel, FAR struct trv_color_lum_s *lum);
 trv_pixel_t trv_color_lum2pixel(FAR struct trv_color_lum_s *lum);
diff --git a/apps/graphics/traveler/include/trv_debug.h b/apps/graphics/traveler/include/trv_debug.h
index d54b1eb13..08b4c2d3b 100644
--- a/apps/graphics/traveler/include/trv_debug.h
+++ b/apps/graphics/traveler/include/trv_debug.h
@@ -93,13 +93,13 @@
        printf(EXTRA_FMT format EXTRA_ARG, ##__VA_ARGS__)
 
 #    else
-#      define vdbg(x...)
+#      define trv_vdebug(x...)
 #    endif
 
 #  else
 
-#    define dbg(x...)
-#    define vdbg(x...)
+#    define trv_debug(x...)
+#    define trv_vdebug(x...)
 
 #  endif
 #else
@@ -132,7 +132,7 @@
  * arguments, then this additional interface will be built.
  */
 
-#ifndef CONFIG_CPP_HAVE_VARARGS && (CONFIG_GRAPHICS_TRAVELER_DEBUG_LEVEL > 0)
+#if !defined(CONFIG_CPP_HAVE_VARARGS) && CONFIG_GRAPHICS_TRAVELER_DEBUG_LEVEL > 0
 int trv_debug(FAR const char *format, ...);
 #endif
 
diff --git a/apps/graphics/traveler/include/trv_graphics.h b/apps/graphics/traveler/include/trv_graphics.h
index 5364c8bc7..69790e627 100644
--- a/apps/graphics/traveler/include/trv_graphics.h
+++ b/apps/graphics/traveler/include/trv_graphics.h
@@ -42,41 +42,88 @@
 
 #include "trv_types.h"
 
+#include <nuttx/video/fb.h>
+#ifdef CONFIG_NX
+#  include <nuttx/nx/nx.h>
+#endif
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#if defined(CONFIG_GRAPHICS_TRAVELER_RGB16_565)
+#  define TRV_BPP        16
+#  define TRV_COLOR_FMT  FB_FMT_RGB16_565
+#elif defined(CONFIG_GRAPHICS_TRAVELER_RGB32_888)
+#  define TRV_BPP        32
+#  define TRV_COLOR_FMT  FB_FMT_RGB32
+#else
+#  error No color format defined
+#endif
+
+#define MAX_REND_WIDTH   480
+#define MAX_REND_HEIGHT  240
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/
 
+#if TRV_BPP == 16
+typedef uint16_t dev_pixel_t;  /* Width of one hardware pixel */
+#elif TRV_BPP == 32
+typedef uint32_t dev_pixel_t;  /* Width of one hardware pixel */
+#endif
+
 struct trv_palette_s
 {
   int ncolors;                  /* Number of colors in the look-up table */
-  FAR nxgl_mxpixel_t *lut;      /* Color lookup table */
+  FAR dev_pixel_t *lut;         /* Color lookup table */
 };
 
 struct trv_graphics_info_s
 {
-  nxgl_coord_t width;           /* Image width */
-  nxgl_coord_t height;          /* Image height */
+#ifdef CONFIG_NX
+  NXHANDLE hnx;                 /* The connection handle */
+  NXHANDLE bgwnd;               /* Background window handle */
+#else
+  trv_coord_t stride;           /* Length of a line in bytes */
+#endif
+  trv_coord_t hwwidth;          /* Display width (pixels) */
+  trv_coord_t hwheight;         /* Display height (rows) */
+  trv_coord_t swwidth;          /* Software render width (pixels) */
+  trv_coord_t swheight;         /* Software render height height (rows) */
+  uint8_t vscale;               /* Log2 vertical image scale factor */
+  uint8_t hscale;               /* Log2 horizontal image scale factor */
   struct trv_palette_s palette; /* Color palette */
-  FAR nxgl_mxpixel_t *buffer;   /* Hardware framebuffer */
+  FAR dev_pixel_t *hwbuffer;    /* Hardware frame buffer */
+  FAR trv_pixel_t *swbuffer;    /* Software render buffer */
 };
 
-struct trv_framebuffer_s
-{
-  nxgl_coord_t width;           /* Image width */
-  nxgl_coord_t height;          /* Image height */
-  FAR trv_pixel_t *buffer;      /* Software render buffer */
-};
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifdef CONFIG_NX
+extern FAR const struct nx_callback_s *g_trv_nxcallback;
+extern sem_t g_trv_nxevent;
+extern volatile bool g_trv_nxresolution;
+#ifdef CONFIG_NX_MULTIUSER
+extern volatile bool g_trv_nxrconnected;
+#endif
+#endif
 
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
 
-int trv_graphics_initialize(uint16_t width, uint16_t height,
-                            uint8_t scale_factor,
-                            FAR struct trv_graphics_info_s *ginfo);
-void trv_graphics_terminate(void);
+int trv_graphics_initialize(FAR struct trv_graphics_info_s *ginfo);
+void trv_graphics_terminate(FAR struct trv_graphics_info_s *ginfo);
 trv_pixel_t trv_graphics_index2pixel(int index);
-void trv_display_update(struct trv_framebuffer_s *fb);
+void trv_display_update(struct trv_graphics_info_s *fb);
 trv_pixel_t *trv_get_renderbuffer(uint16_t width, uint16_t height);
 
+#ifdef CONFIG_NX_MULTIUSER
+FAR void *trv_nxlistener(FAR void *arg)
+#endif
+
 #endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_GRAPHICS_H */
diff --git a/apps/graphics/traveler/include/trv_main.h b/apps/graphics/traveler/include/trv_main.h
index 08d16ef2b..62c5ad61f 100644
--- a/apps/graphics/traveler/include/trv_main.h
+++ b/apps/graphics/traveler/include/trv_main.h
@@ -56,6 +56,6 @@ extern bool g_trv_terminate;
  * Public Function Prototypes
  ****************************************************************************/
 
-void trv_abort(FAR char *format, ...);
+void trv_abort(FAR char *format, ...) noreturn_function;
 
 #endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_MAIN_H */
diff --git a/apps/graphics/traveler/include/trv_mem.h b/apps/graphics/traveler/include/trv_mem.h
new file mode 100644
index 000000000..5ae3866cf
--- /dev/null
+++ b/apps/graphics/traveler/include/trv_mem.h
@@ -0,0 +1,52 @@
+/****************************************************************************
+ * apps/graphics/traveler/include/trv_mem.h
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_MEM_H
+#define __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_MEM_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include "trv_types.h"
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+FAR void *trv_malloc(size_t size);
+void trv_free(FAR void *memory);
+
+#endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_MEM_H */
diff --git a/apps/graphics/traveler/include/trv_raycntl.h b/apps/graphics/traveler/include/trv_raycntl.h
index 01cbed191..ffcf2b6d3 100644
--- a/apps/graphics/traveler/include/trv_raycntl.h
+++ b/apps/graphics/traveler/include/trv_raycntl.h
@@ -41,6 +41,7 @@
  ****************************************************************************/
 
 #include "trv_types.h"
+#include "trv_graphics.h"
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -54,10 +55,7 @@
  * Public Function Prototypes
  ****************************************************************************/
 
-extern uint8_t *trv_raycaster_initialize(uint16_t screen_width,
-                                         uint16_t screen_height,
-                                         uint8_t scale_factor,
-                                         FAR uint8_t *screen_buffer);
-extern void trv_raycaster(FAR struct trv_camera_s *player);
+void trv_raycaster(FAR struct trv_camera_s *player,
+                   FAR struct trv_graphics_info_s *ginfo);
 
 #endif /* __APPS_GRAPHICS_TRAVELER_INCLUDE_TRV_RAYCNTL_H */
diff --git a/apps/graphics/traveler/include/trv_types.h b/apps/graphics/traveler/include/trv_types.h
index 6fbf61071..2eb9f2618 100644
--- a/apps/graphics/traveler/include/trv_types.h
+++ b/apps/graphics/traveler/include/trv_types.h
@@ -41,12 +41,12 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <nuttx/compiler.h>
 
+#include <sys/types.h>
 #include <stdint.h>
 #include <stdbool.h>
 
-#include <nuttx/nx/nxglib.h>
-
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -63,7 +63,8 @@
  * Public Types
  ****************************************************************************/
 
-typedef uint8_t trv_pixel_t;
+typedef uint8_t trv_pixel_t;  /* Width of one pixel in rendering phase */
+typedef int16_t trv_coord_t;  /* Contains one display coordinate */
 
 /****************************************************************************
  * Public Function Prototypes
diff --git a/apps/graphics/traveler/include/trv_world.h b/apps/graphics/traveler/include/trv_world.h
index b590e2f87..939ec1820 100644
--- a/apps/graphics/traveler/include/trv_world.h
+++ b/apps/graphics/traveler/include/trv_world.h
@@ -52,11 +52,11 @@
 
 struct trv_camera_s
 {
-  nxgl_coord_t x;      /* Camera X position */
-  nxgl_coord_t y;      /* Camera Y position */
-  nxgl_coord_t z;      /* Camera Z position */
-  int16_t      yaw;    /* Camera yaw orientation */
-  int16_t      pitch;  /* Camera pitch orientation */
+  trv_coord_t x;      /* Camera X position */
+  trv_coord_t y;      /* Camera Y position */
+  trv_coord_t z;      /* Camera Z position */
+  int16_t     yaw;    /* Camera yaw orientation */
+  int16_t     pitch;  /* Camera pitch orientation */
 };
 
 /****************************************************************************
diff --git a/apps/graphics/traveler/src/trv_graphics.c b/apps/graphics/traveler/src/trv_graphics.c
new file mode 100755
index 000000000..6742147aa
--- /dev/null
+++ b/apps/graphics/traveler/src/trv_graphics.c
@@ -0,0 +1,572 @@
+/****************************************************************************
+ * apps/graphics/traveler/src/trv_graphics.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * 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 "trv_types.h"
+#include "trv_main.h"
+#include "trv_mem.h"
+#include "trv_color.h"
+#include "trv_debug.h"
+#include "trv_graphics.h"
+
+#include <string.h>
+#ifdef CONFIG_NX_MULTIUSER
+#  include <semaphore.h>
+#endif
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifdef CONFIG_NX
+FAR const struct nx_callback_s *g_trv_nxcallback;
+sem_t g_trv_nxevent = SEM_INITIZIALIZER(0);
+bool g_trv_nxresolution = false;
+#ifdef CONFIG_NX_MULTIUSER
+bool g_trv_nxrconnected = false;
+#endif
+#endif
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: trv_get_fbdev
+ *
+ * Description:
+ *   Get the system framebuffer device
+ *
+ ****************************************************************************/
+
+#ifndef CONFIG_NX_MULTIUSER
+static FAR struct fb_vtable_s *trv_get_fbdev(void)
+{
+  FAR struct fb_vtable_s *fbdev;
+  int ret;
+
+  /* Initialize the frame buffer device */
+
+  ret = up_fbinitialize();
+  if (ret < 0)
+    {
+      trv_abort("up_fbinitialize failed: %d\n", -ret);
+    }
+
+  /* Set up to use video plane 0.  There is no support for anything but
+   * video plane 0.
+   */
+
+  fbdev = up_fbgetvplane(0);
+  if (!fbdev)
+    {
+      trv_abort("up_fbgetvplane(0) failed\n");
+    }
+
+  return fbdev;
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_fb_initialize
+ *
+ * Description:
+ *   Get the system framebuffer device
+ *
+ ****************************************************************************/
+
+#if !defined(CONFIG_NX_MULTIUSER) && !defined(CONFIG_NX)
+static void trv_fb_initialize(FAR struct trv_graphics_info_s *ginfo)
+{
+  struct fb_videoinfo_s vinfo;
+  struct fb_planeinfo_s pinfo;
+  FAR struct fb_vtable_s *fbdev;
+  int ret;
+
+  /* Get the framebuffer device */
+
+  fbdev = trv_get_fbdev();
+
+  /* Get information about video plane 0 */
+
+  ret = fbdev->getvideoinfo(fbdev, &vinfo);
+  if (ret < 0)
+    {
+      trv_abort("getvideoinfo() failed\n");
+    }
+
+  ginfo->hwwidth  = vinfo.xres;
+  ginfo->hwheight = vinfo.yres;
+
+  ret = fbdev->getplaneinfo(fbdev, 0, &pinfo);
+  if (ret < 0)
+    {
+      trv_abort("getplaneinfo() failed\n");
+    }
+
+  ginfo->stride   = pinfo.stride;
+  ginfo->hwbuffer = pinfo.fbmem;
+
+  if (vinfo.fmt != TRV_COLOR_FMT || pinfo.bpp != TRV_BPP)
+    {
+      trv_abort("Bad color format(%d)/bpp(%b)\n", vinfo.fmt, pinfo.bpp);
+    }
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_use_bgwindow
+ *
+ * Description:
+ *   Get the NX background window
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NX
+static void trv_use_bgwindow(FAR struct trv_graphics_info_s *ginfo)
+{
+  /* Get the background window */
+
+  ret = nx_requestbkgd(g_hnx, &g_trv_nxcallback, ginfo);
+  if (ret < 0)
+    {
+      trv_abort("nx_requestbkgd failed: %d\n", errno);
+    }
+
+  /* Wait until we have the screen resolution.  We'll have this immediately
+   * unless we are dealing with the NX server.
+   */
+
+  while (!g_trv_nxresolution)
+    {
+      (void)sem_wait(&g_trv_nxevent);
+    }
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_nxsu_initialize
+ ****************************************************************************/
+
+#if defined(CONFIG_NX) && !defined(CONFIG_NX_MULTIUSER)
+static inline int trv_nxsu_initialize(FAR struct trv_graphics_info_s *ginfo)
+{
+  FAR struct fb_vtable_s *fbdev;
+  int ret;
+
+  /* Get the framebuffer device */
+
+  fbdev = trv_get_fbdev();
+
+  /* Open NX */
+
+  ginfo->hnx = nx_open(fbdev);
+  if (!ginfo->hnx)
+    {
+      trv_abort("trv_nxsu_initialize: nx_open failed: %d\n", errno);
+    }
+
+  /* And use the background window */
+
+  trv_use_bgwindow(ginfo);
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_servertask
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_MULTIUSER
+int trv_servertask(int argc, char *argv[])
+{
+  FAR struct fb_vtable_s *fbdev;
+  int ret;
+
+  /* Get the framebuffer device */
+
+  fbdev = trv_get_fbdev();
+
+  /* Then start the server */
+
+  ret = nx_run(dev);
+  trv_abort("nx_run returned: %d\n", errno);
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_nxmu_initialize
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_MULTIUSER
+static inline int trv_nxmu_initialize(FAR struct trv_graphics_info_s *ginfo)
+{
+  struct sched_param param;
+  pthread_t thread;
+  pid_t servrid;
+  int ret;
+
+  /* Set the client task priority */
+
+  param.sched_priority = CONFIG_EXAMPLES_NX_CLIENTPRIO;
+  ret = sched_setparam(0, &param);
+  if (ret < 0)
+    {
+      printf("nxeg_initialize: sched_setparam failed: %d\n" , ret);
+      g_exitcode = NXEXIT_SCHEDSETPARAM;
+      return ERROR;
+    }
+
+  /* Start the server task */
+
+  printf("nxeg_initialize: Starting trv_servertask task\n");
+  servrid = task_create("NX Server", CONFIG_EXAMPLES_NX_SERVERPRIO,
+                        CONFIG_EXAMPLES_NX_STACKSIZE, trv_servertask, NULL);
+  if (servrid < 0)
+    {
+      printf("nxeg_initialize: Failed to create trv_servertask task: %d\n", errno);
+      g_exitcode = NXEXIT_TASKCREATE;
+      return ERROR;
+    }
+
+  /* Wait a bit to let the server get started */
+
+  sleep(1);
+
+  /* Connect to the server */
+
+  ginfo->hnx = nx_connect();
+  if (ginfo->hnx)
+    {
+       pthread_attr_t attr;
+
+       /* Start a separate thread to listen for server events.  This is probably
+        * the least efficient way to do this, but it makes this example flow more
+        * smoothly.
+        */
+
+       (void)pthread_attr_init(&attr);
+       param.sched_priority = CONFIG_EXAMPLES_NX_LISTENERPRIO;
+       (void)pthread_attr_setschedparam(&attr, &param);
+       (void)pthread_attr_setstacksize(&attr, CONFIG_EXAMPLES_NX_STACKSIZE);
+
+       ret = pthread_create(&thread, &attr, trv_nxlistener, NULL);
+       if (ret != 0)
+         {
+            printf("nxeg_initialize: pthread_create failed: %d\n", ret);
+            g_exitcode = NXEXIT_PTHREADCREATE;
+            return ERROR;
+         }
+
+       /* Don't return until we are connected to the server */
+
+       while (!g_trv_nxrconnected)
+         {
+           /* Wait for the listener thread to wake us up when we really
+            * are connected.
+            */
+
+           (void)sem_wait(&g_trv_nxevent);
+         }
+    }
+  else
+    {
+      printf("nxeg_initialize: nx_connect failed: %d\n", errno);
+      g_exitcode = NXEXIT_NXCONNECT;
+      return ERROR;
+    }
+
+  /* And use the background window */
+
+  trv_use_bgwindow(ginfo);
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_row_update
+ *
+ * Description:
+ *   Expand one one either directly into the frame buffer or else into an
+ *   intermediate line buffer.
+ *
+ ****************************************************************************/
+
+void trv_row_update(struct trv_graphics_info_s *ginfo,
+                    FAR const trv_pixel_t *src,
+                    FAR dev_pixel_t *dest)
+{
+  trv_coord_t hexpand;
+  dev_pixel_t pixel;
+  trv_coord_t srccol;
+  int i;
+
+  /* Loop for each column in the src render buffer */
+
+  hexpand = (1 << ginfo->hscale);
+
+  for (srccol = 0; srccol < ginfo->swwidth; srccol++)
+    {
+      /* Map the source pixel */
+
+      pixel = ginfo->palette.lut[*src++];
+
+      /* Copy it to the destination, expanding as necessary */
+
+      for (i = 0; i < hexpand; i++)
+        {
+          *dest++ = pixel;
+        }
+    }
+}
+
+/****************************************************************************
+ * Name: trv_row_tranfer
+ *
+ * Description:
+ *   Transfer one line from the line buffer to the NX window.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NX
+void trv_display_update(struct trv_graphics_info_s *ginfo,
+                        FAR dev_pixel_t *dest, trv_coord_t destrow)
+{
+  /* Transfer the row buffer to the NX window */
+#warning Missing logic
+
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: trv_graphics_initialize
+ *
+ * Description:
+ ****************************************************************************/
+
+int trv_graphics_initialize(FAR struct trv_graphics_info_s *ginfo)
+{
+  int swwidth;
+  int swheight;
+  int scale;
+  int ret;
+
+  /* Initialize the graphics device and get information about the display */
+
+#if !defined(CONFIG_NX)
+  trv_fb_initialize(ginfo);
+#elif defined(CONFIG_NX_MULTIUSER)
+  trv_nxmu_initialize(ginfo);
+#else
+  trv_nxsu_initialize(ginfo);
+#endif
+
+  /* Check if we need to scale the image */
+
+  swwidth = ginfo->hwwidth;
+  scale   = 0;
+
+  while (swwidth > MAX_REND_WIDTH)
+    {
+      swwidth >>= 1;
+      scale++;
+    }
+
+  ginfo->swwidth = swwidth;
+  ginfo->hscale   = scale;
+
+  swheight = ginfo->hwheight;
+  scale    = 0;
+
+  while (swheight > MAX_REND_WIDTH)
+    {
+      swheight >>= 1;
+      scale++;
+    }
+
+  ginfo->swheight = swheight;
+  ginfo->vscale   = scale;
+
+  /* Allocate buffers
+   *
+   * ginfo->swbuffer - Software renders into this buffer using an 8-bit
+   *   encoding and perhaps at a different resolution that the final
+   *   image.
+   */
+
+   ginfo->swbuffer = (trv_pixel_t*)
+     trv_malloc(swwidth * swheight * sizeof(trv_pixel_t));
+   if (!ginfo->swbuffer)
+     {
+       trv_abort("ERROR: Failed to allocate render buffer\n");
+     }
+
+  /* Using the framebuffer driver:
+   *   ginfo->hwbuffer - This address of the final, expanded frame image.
+   *   This address is determined by hardware and is neither allocated
+   *   nor freed.
+   *
+   * Using NX
+   *   ginfo->hwbuffer - This address of one line of the final expanded
+   *   image that must transferred to the window.
+   */
+
+#ifdef CONFIG_NX
+   ginfo->hwbuffer = (trv_pixel_t*)
+     trv_malloc(ginfo->hwwidth * sizeof(dev_pixel_t));
+   if (!ginfo->hwbuffer)
+     {
+       trv_abort("ERROR: Failed to allocate hardware line buffer\n");
+     }
+#endif
+
+  /* Allocate color mapping information */
+
+  ret = trv_color_allocate(&ginfo->palette);
+  if (ret < 0)
+    {
+      trv_abort("ERROR trv_color_allocate failed: %d");
+    }
+
+  trv_vdebug("%d colors allocated\n", ginfo->palette.ncolors);
+  return OK;
+}
+
+/****************************************************************************
+ * Name: trv_graphics_terminate
+ *
+ * Description:
+ ****************************************************************************/
+
+void trv_graphics_terminate(FAR struct trv_graphics_info_s *ginfo)
+{
+  /* Free palette */
+
+  trv_color_free(&ginfo->palette);
+
+  /* Free image buffers */
+
+  if (ginfo->swbuffer)
+    {
+      trv_free(ginfo->swbuffer);
+      ginfo->swbuffer = NULL;
+    }
+
+#ifdef CONFIG_NX
+  if (ginfo->hwbuffer)
+    {
+      trv_free(ginfo->hwbuffer);
+      ginfo->hwbuffer = NULL;
+    }
+
+  /* Close/disconnect NX */
+#warning "Missing Logic"
+#endif
+}
+
+/****************************************************************************
+ * Name: trv_display_update
+ *
+ * Description:
+ ****************************************************************************/
+
+void trv_display_update(struct trv_graphics_info_s *ginfo)
+{
+  FAR const uint8_t *src = (FAR const uint8_t *)ginfo->swbuffer;
+  FAR uint8_t *dest = (FAR uint8_t *)ginfo->hwbuffer;
+  trv_coord_t srcrow;
+#ifdef CONFIG_NX
+  trv_coord_t destrow;
+#else
+  FAR uint8_t *first;
+  trv_coord_t lnwidth;
+#endif
+  trv_coord_t vexpand;
+  int i;
+
+  /* Loop for each row in the srce render buffer */
+
+  vexpand = (1 << ginfo->vscale);
+#ifdef CONFIG_NX
+  destrow = 0;
+#else
+  lnwidth = ginfo->hwwidth * sizeof(dev_pixel_t);
+#endif
+
+  for (srcrow = 0; srcrow < ginfo->swheight; srcrow++)
+    {
+      /* Transfer the row to the device row/buffer */
+
+      trv_row_update(ginfo, (FAR const trv_pixel_t *)src,
+                     (FAR dev_pixel_t *)dest);
+
+#ifdef CONFIG_NX
+      /* Transfer the row buffer to the NX window */
+
+      trv_row_tranfer(ginfo, dest, destrow);
+      destrow++;
+#else
+      first = dest;
+      dest += ginfo->stride;
+#endif
+
+      /* Then replicate as many times as is necessary */
+
+      for (i = 1; i < vexpand; i++)
+        {
+#ifdef CONFIG_NX
+          /* Transfer the row buffer to the NX window */
+
+          trv_row_tranfer(ginfo, dest, destrow);
+          destrow++;
+#else
+          /* Point to the next row in the frame buffer */
+
+          memcpy(dest, first, lnwidth);
+          dest += ginfo->stride;
+#endif
+        }
+
+      /* Point to the next src row */
+
+      src += ginfo->swwidth;
+    }
+}
+
diff --git a/apps/graphics/traveler/src/trv_main.c b/apps/graphics/traveler/src/trv_main.c
index 604ff2975..fc9de19f6 100755
--- a/apps/graphics/traveler/src/trv_main.c
+++ b/apps/graphics/traveler/src/trv_main.c
@@ -52,7 +52,7 @@
 #include "trv_rayrend.h"
 #include "trv_input.h"
 #include "trv_graphics.h"
-#include "trv_color.h"
+#include "trv_debug.h"
 #include "trv_main.h"
 
 #if CONFIG_GRAPHICS_TRAVELER_PERFMON
@@ -78,10 +78,21 @@ static double trv_current_time(void);
 bool g_trv_terminate;
 
 /****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void trv_exit(int exitcode) noreturn_function;
+static void trv_usage(char *execname);
+#ifdef CONFIG_GRAPHICS_TRAVELER_PERFMON
+static double trv_current_time(void);
+#endif
+
+/****************************************************************************
  * Private Data
  *************************************************************************/
 
 static const char g_default_worldfile[] = "transfrm.wld";
+static FAR struct trv_graphics_info_s g_trv_ginfo;
 
 /****************************************************************************
  * Private Functions
@@ -93,7 +104,7 @@ static const char g_default_worldfile[] = "transfrm.wld";
  * Description:
  ****************************************************************************/
 
-static void trv_exit(int exitCode)
+static void trv_exit(int exitcode)
 {
   /* Release memory held by the ray casting engine */
 
@@ -102,9 +113,9 @@ static void trv_exit(int exitCode)
   /* Close off input */
 
   trv_input_terminate();
-  trv_graphics_terminate();
+  trv_graphics_terminate(&g_trv_ginfo);
 
-  exit(exitCode);
+  exit(exitcode);
 }
 
 /****************************************************************************
@@ -117,7 +128,6 @@ static void trv_usage(char *execname)
 {
   fprintf(stderr, "Usage: %s [-b] [-p<path>] [world]\n", execname);
   fprintf(stderr, "Where:\n");
-  fprintf(stderr, "  -b       Selects 640x400 window (default is 320x200)\n");
   fprintf(stderr, "  -p<path> Selects the path to the world data file\n");
   fprintf(stderr, "  world    Selects the world file name\n");
   exit(EXIT_FAILURE);
@@ -155,10 +165,7 @@ int main(int argc, FAR char *argv[])
 int traveler_main(int argc, char *argv[])
 #endif
 {
-  FAR struct trv_graphics_info_s ginfo;
-  struct trv_framebuffer_s frame;
   FAR const char *world_filename;
-  uint8_t scale_factor = 1;
 #ifdef CONFIG_GRAPHICS_TRAVELER_PERFMON
   int32_t frame_count = 0;
   double elapsed_time = 0.0;
@@ -178,10 +185,6 @@ int traveler_main(int argc, char *argv[])
           ptr++;
           switch (*ptr)
             {
-            case 'b':
-              scale_factor = 2;
-              break;
-
             case 'p' :
               ptr++;
               printf("World data path = %s\n", ptr);
@@ -204,31 +207,21 @@ int traveler_main(int argc, char *argv[])
         }
     }
 
-  printf("World data file = %s\n", world_filename);
+  trv_debug("World data file = %s\n", world_filename);
 
   /* Initialize the graphics interface */
 
-  ret = trv_graphics_initialize(320, 200, scale_factor, &ginfo);
-  if (ret < 0)
-    {
-      fprintf(stderr, "ERROR: trv_graphics_initialize failed: %d\n", ret);
-      trv_exit(EXIT_FAILURE);
-    }
+  trv_graphics_initialize(&g_trv_ginfo);
 
   /* Load the word data structures */
 
   ret = trv_world_create(world_filename);
   if (ret < 0)
     {
-      fprintf(stderr, "ERROR: %d loading world file %s: %d\n",
-              world_filename, ret);
-      trv_exit(EXIT_FAILURE);
+      trv_abort("ERROR: %d loading world file %s: %d\n",
+                world_filename, ret);
     }
 
-  /* We can now release any color mapping tables */
-
-  trv_color_endmapping();
-
   /* Set the player's POV in the new world */
 
   trv_pov_reset();
@@ -237,19 +230,6 @@ int traveler_main(int argc, char *argv[])
 
   trv_door_initialize();
 
-  /* Initialize the ray cast engine */
-
-  frame.width  = ginfo.width;
-  frame.height = ginfo.height;
-  frame.buffer = trv_get_renderbuffer(ginfo.width, ginfo.height);
-
-  if (!trv_raycaster_initialize(frame.width, frame.height,
-                                scale_factor, frame.buffer))
-    {
-      fprintf(stderr, "Error:  Initializing ray cast engine.\n");
-      trv_exit(EXIT_FAILURE);
-    }
-
   /* Set up to receive input */
 
   trv_input_initialize();
@@ -276,11 +256,11 @@ int traveler_main(int argc, char *argv[])
 
       /* Render the 3-D view */
 
-      trv_raycaster(&g_trv_player);
+      trv_raycaster(&g_trv_player, &g_trv_ginfo);
 
       /* Display the world. */
 
-      trv_display_update(&frame);
+      trv_display_update(&g_trv_ginfo);
 #ifdef CONFIG_GRAPHICS_TRAVELER_PERFMON
       frame_count++;
       elapsed_time += trv_current_time() - start_time;
diff --git a/apps/graphics/traveler/src/trv_mem.c b/apps/graphics/traveler/src/trv_mem.c
new file mode 100755
index 000000000..84e85c3d0
--- /dev/null
+++ b/apps/graphics/traveler/src/trv_mem.c
@@ -0,0 +1,85 @@
+/****************************************************************************
+ * apps/graphics/traveler/src/trv_mem.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * 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 "trv_types.h"
+#include "trv_main.h"
+#include "trv_mem.h"
+
+#include <stdlib.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: trv_malloc
+ *
+ * Description:
+ ****************************************************************************/
+
+FAR void *trv_malloc(size_t size)
+{
+  FAR void *memory;
+
+  memory = malloc(size);
+  if (memory == NULL)
+    {
+      trv_abort("Out of memory (trv_malloc %x bytes)", size);
+    }
+
+  return memory;
+}
+
+/****************************************************************************
+ * Name: trv_free
+ *
+ * Description:
+ ****************************************************************************/
+
+void trv_free(void *memory)
+{
+  if (memory == NULL)
+    {
+      trv_abort("Freeing NULL");
+    }
+  else
+    {
+      free(memory);
+    }
+}
diff --git a/apps/graphics/traveler/src/trv_nxbkgd.c b/apps/graphics/traveler/src/trv_nxbkgd.c
new file mode 100644
index 000000000..4bd8a6997
--- /dev/null
+++ b/apps/graphics/traveler/src/trv_nxbkgd.c
@@ -0,0 +1,175 @@
+/****************************************************************************
+ * apps/graphics/traveler/trv_nxbkgd.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * 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 "trv_types.h"
+
+#include <string.h>
+#include <semaphore.h>
+#include <errno.h>
+
+#include <nuttx/nx/nx.h>
+#include <nuttx/nx/nxfonts.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void trv_nxredraw(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
+                        bool morem, FAR void *arg);
+static void trv_nxposition(NXWINDOW hwnd, FAR const struct nxgl_size_s *size,
+                          FAR const struct nxgl_point_s *pos,
+                          FAR const struct nxgl_rect_s *bounds,
+                          FAR void *arg);
+#ifdef CONFIG_NX_XYINPUT
+static void trv_nxmousein(NXWINDOW hwnd, FAR const struct nxgl_point_s *pos,
+                         uint8_t buttons, FAR void *arg);
+#endif
+
+#ifdef CONFIG_NX_KBD
+static void trv_nxkbdin(NXWINDOW hwnd, uint8_t nch, FAR const uint8_t *ch,
+                       FAR void *arg);
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* Background window call table */
+
+const struct nx_callback_s g_trv_nxcallback =
+{
+  trv_nxredraw,   /* redraw */
+  trv_nxposition  /* position */
+#ifdef CONFIG_NX_XYINPUT
+  , trv_nxmousein /* mousein */
+#endif
+#ifdef CONFIG_NX_KBD
+  , trv_nxkbdin   /* my kbdin */
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: trv_nxredraw
+ ****************************************************************************/
+
+static void trv_nxredraw(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
+                        bool more, FAR void *arg)
+{
+}
+
+/****************************************************************************
+ * Name: trv_nxposition
+ ****************************************************************************/
+
+static void trv_nxposition(NXWINDOW hwnd, FAR const struct nxgl_size_s *size,
+                          FAR const struct nxgl_point_s *pos,
+                          FAR const struct nxgl_rect_s *bounds,
+                          FAR void *arg)
+{
+  FAR struct trv_graphics_info_s *ginfo = (FAR struct trv_graphics_info_s *)arg;
+
+  /* Report the position */
+
+  gvdbg("hwnd=%p size=(%d,%d) pos=(%d,%d) bounds={(%d,%d),(%d,%d)}\n",
+        hwnd, size->w, size->h, pos->x, pos->y,
+        bounds->pt1.x, bounds->pt1.y, bounds->pt2.x, bounds->pt2.y);
+
+  /* Have we picked off the window bounds yet? */
+
+  if (!g_trv_nxresolution)
+    {
+      /* Save the background window handle */
+
+      ginnfo->bgwnd = hwnd;
+
+      /* Save the background window size */
+
+      ginfo->width  = size->w;
+      ginfo->height = size->h;
+
+      g_trv_nxresolution = true;
+      sem_post(&g_trv_nxevent);
+      gvdbg("Have width=%d height=%d\n", ginfo->width, ginfo->height);
+    }
+}
+
+/****************************************************************************
+ * Name: trv_nxmousein
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_XYINPUT
+static void trv_nxmousein(NXWINDOW hwnd, FAR const struct nxgl_point_s *pos,
+                         uint8_t buttons, FAR void *arg)
+{
+  printf("trv_nxmousein: hwnd=%p pos=(%d,%d) button=%02x\n",
+         hwnd,  pos->x, pos->y, buttons);
+}
+#endif
+
+/****************************************************************************
+ * Name: trv_nxkbdin
+ ****************************************************************************/
+
+#ifdef CONFIG_NX_KBD
+static void trv_nxkbdin(NXWINDOW hwnd, uint8_t nch, FAR const uint8_t *ch,
+                       FAR void *arg)
+{
+  gvdbg("hwnd=%p nch=%d\n", hwnd, nch);
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
diff --git a/apps/graphics/traveler/src/trv_nxserver.c b/apps/graphics/traveler/src/trv_nxserver.c
new file mode 100644
index 000000000..e2cedaa28
--- /dev/null
+++ b/apps/graphics/traveler/src/trv_nxserver.c
@@ -0,0 +1,114 @@
+/****************************************************************************
+ * apps/graphics/traveler/trv_nxlistener.c
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * 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 "trv_types.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sched.h>
+#include <errno.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/nx/nx.h>
+#include <nuttx/video/fb.h>
+
+#ifdef CONFIG_NX_MULTIUSER
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: trv_nxlistener
+ ****************************************************************************/
+
+FAR void *trv_nxlistener(FAR void *arg)
+{
+  int ret;
+
+  /* Process events forever */
+
+  for (;;)
+    {
+      /* Handle the next event.  If we were configured blocking, then
+       * we will stay right here until the next event is received.  Since
+       * we have dedicated a while thread to servicing events, it would
+       * be most natural to also select CONFIG_NX_BLOCKING -- if not, the
+       * following would be a tight infinite loop (unless we added addition
+       * logic with nx_eventnotify and sigwait to pace it).
+       */
+
+      ret = nx_eventhandler(g_hnx);
+      if (ret < 0)
+        {
+          /* An error occurred... assume that we have lost connection with
+           * the server.
+           */
+
+          trv_abort("Lost server connection: %d\n", errno);
+        }
+
+      /* If we received a message, we must be connected */
+
+      if (!g_trv_nxrconnected)
+        {
+          g_trv_nxrconnected = true;
+          sem_post(&g_trv_nxevent);
+          trv_debug("Connected to server\n");
+        }
+    }
+}
+
+#endif /* CONFIG_NX_MULTIUSER */