examples/cpuhog and serialblaster from Bob Doiron

ChangeLog.txt

@@ -891,4 +891,6 @@
 	* apps/system/sdcard:  Remove an STM32 dependency.  From Bob Doiron
 	  (2014-4-21).
 	* apps/nshlib: malloc/free IOBUFFER for 'cat' and 'hexdump' commands
-	  instead of using the stack.  From Bob Doiron (2014-4-21).
+	  instead of using the stack.  From Bob Doiron (2014-4-21).
+	* apps/examples/cpuhog and serialblaster:  Stress test examples added
+	  by Bob Doiron (2014-4-22).

examples/Kconfig

@@ -8,6 +8,7 @@ source "$APPSDIR/examples/buttons/Kconfig"
 source "$APPSDIR/examples/can/Kconfig"
 source "$APPSDIR/examples/cc3000/Kconfig"
 source "$APPSDIR/examples/configdata/Kconfig"
+source "$APPSDIR/examples/cpuhog/Kconfig"
 source "$APPSDIR/examples/cxxtest/Kconfig"
 source "$APPSDIR/examples/dhcpd/Kconfig"
 source "$APPSDIR/examples/elf/Kconfig"
@@ -49,6 +50,7 @@ source "$APPSDIR/examples/relays/Kconfig"
 source "$APPSDIR/examples/rgmp/Kconfig"
 source "$APPSDIR/examples/romfs/Kconfig"
 source "$APPSDIR/examples/sendmail/Kconfig"
+source "$APPSDIR/examples/serialblaster/Kconfig"
 source "$APPSDIR/examples/serloop/Kconfig"
 source "$APPSDIR/examples/slcd/Kconfig"
 source "$APPSDIR/examples/flash_test/Kconfig"

examples/Make.defs

@@ -54,6 +54,10 @@ ifeq ($(CONFIG_EXAMPLES_CONFIGDATA),y)
 CONFIGURED_APPS += examples/configdata
 endif
 
+ifeq ($(CONFIG_EXAMPLES_CPUHOG),y)
+CONFIGURED_APPS += examples/cpuhog
+endif
+
 ifeq ($(CONFIG_EXAMPLES_CXXTEST),y)
 CONFIGURED_APPS += examples/cxxtest
 endif
@@ -222,6 +226,10 @@ ifeq ($(CONFIG_EXAMPLES_SENDMAIL),y)
 CONFIGURED_APPS += examples/sendmail
 endif
 
+ifeq ($(CONFIG_EXAMPLES_SERIALBLASTER),y)
+CONFIGURED_APPS += examples/serialblaster
+endif
+
 ifeq ($(CONFIG_EXAMPLES_SERLOOP),y)
 CONFIGURED_APPS += examples/serloop
 endif

examples/Makefile

@@ -37,14 +37,15 @@
 
 # Sub-directories
 
-SUBDIRS  = adc buttons can cc3000 cxxtest dhcpd discover elf flash_test
+SUBDIRS  = adc buttons can cc3000 cpuhog cxxtest dhcpd discover elf
-SUBDIRS += ftpc ftpd hello helloxx hidkbd igmp i2schar json keypadtest
+SUBDIRS += flash_test ftpc ftpd hello helloxx hidkbd igmp i2schar json
-SUBDIRS += lcdrw mm modbus mount mtdpart nettest nrf24l01_term nsh null nx
+SUBDIRS += keypadtest lcdrw mm modbus mount mtdpart nettest nrf24l01_term
-SUBDIRS += nxconsole nxffs nxflat nxhello nximage nxlines nxtext ostest
+SUBDIRS += nsh null nx nxconsole nxffs nxflat nxhello nximage nxlines
-SUBDIRS += pashello pipe poll posix_spawn pwm qencoder random relays rgmp
+SUBDIRS += nxtext ostest pashello pipe poll posix_spawn pwm qencoder random
-SUBDIRS += romfs sendmail serloop slcd smart smart_test tcpecho telnetd
+SUBDIRS += relays rgmp romfs sendmail serialblaster serloop slcd smart
-SUBDIRS += thttpd tiff touchscreen udp uip usbserial usbterm watchdog
+SUBDIRS += smart_test tcpecho telnetd thttpd tiff touchscreen udp uip
-SUBDIRS += wget wgetjson xmlrpc
+SUBDIRS += usbserial usbterm watchdog wget wgetjson xmlrpc
+
 
 # Sub-directories that might need context setup.  Directories may need
 # context setup for a variety of reasons, but the most common is because
@@ -53,11 +54,11 @@ SUBDIRS += wget wgetjson xmlrpc
 CNTXTDIRS = pwm
 
 ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
-CNTXTDIRS += adc can cc3000 cxxtest dhcpd discover flash_test ftpd
+CNTXTDIRS += adc can cc3000 cpuhog cxxtest dhcpd discover flash_test ftpd
 CNTXTDIRS += hello helloxx i2schar json keypadtestmodbus lcdrw mtdpart
 CNTXTDIRS += nettest nx nxhello nximage nxlines nxtext nrf24l01_term
-CNTXTDIRS += ostest random relays qencoder slcd smart_test tcpecho telnetd
+CNTXTDIRS += ostest random relays qencoder serialblasterslcd smart_test
-CNTXTDIRS += tiff touchscreen usbterm watchdog wgetjson
+CNTXTDIRS += tcpecho telnetd tiff touchscreen usbterm watchdog wgetjson
 endif
 
 all: nothing

examples/README.txt

@@ -121,11 +121,18 @@ examples/configdata
 
   This is a Unit Test for the MTD configuration data driver
 
+examples/cpuhog
+^^^^^^^^^^^^^^^
+
+  Attempts to keep the system busy by passing data through a pipe in loop
+  back mode.  This may be useful if you are trying run down other problems
+  that you think might only occur when the system is very busy.
+
 examples/cxxtest
 ^^^^^^^^^^^^^^^^
 
   This is a test of the C++ standard library.  At present a port of the uClibc++
-  C++ library is available.  Due to licensinging issues, the uClibc++ C++ library
+  C++ library is available.  Due to licensing issues, the uClibc++ C++ library
   is not included in the NuttX source tree by default, but must be installed
   (see misc/uClibc++/README.txt for installation).
 
@@ -1442,6 +1449,13 @@ examples/sendmail
     CONFIG_NETUTILS_UIPLIB=y
     CONFIG_NETUTILS_SMTP=y
 
+examples/serialblaster
+^^^^^^^^^^^^^^^^^^^^^^
+
+  Sends a repeating pattern (the alphabet) out a serial por continuously.
+  This may be useful if you are trying run down other problems that you
+  think might only occur when the serial port usage is high.
+
 examples/serloop
 ^^^^^^^^^^^^^^^^
 

examples/cpuhog/.gitignore

@@ -0,0 +1,11 @@
+/Make.dep
+/.depend
+/.built
+/*.asm
+/*.obj
+/*.rel
+/*.lst
+/*.sym
+/*.adb
+/*.lib
+/*.src

examples/cpuhog/Kconfig

@@ -0,0 +1,13 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config EXAMPLES_CPUHOG
+    bool "CPU Hog"
+    default n
+    ---help---
+        Enable the cpuhog example
+
+if EXAMPLES_CPUHOG
+endif

examples/cpuhog/Makefile

@@ -0,0 +1,109 @@
+############################################################################
+# apps/examples/cpuhog/Makefile
+#
+#   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.
+#
+############################################################################
+
+-include $(TOPDIR)/.config
+-include $(TOPDIR)/Make.defs
+include $(APPDIR)/Make.defs
+
+# do nothing loop to use up cpu time
+
+ASRCS =
+CSRCS = cpuhog_main.c
+
+AOBJS = $(ASRCS:.S=$(OBJEXT))
+COBJS = $(CSRCS:.c=$(OBJEXT))
+
+SRCS = $(ASRCS) $(CSRCS)
+OBJS = $(AOBJS) $(COBJS)
+
+ifeq ($(CONFIG_WINDOWS_NATIVE),y)
+  BIN = ..\..\libapps$(LIBEXT)
+else
+ifeq ($(WINTOOL),y)
+  BIN = ..\\..\\libapps$(LIBEXT)
+else
+  BIN = ../../libapps$(LIBEXT)
+endif
+endif
+
+ROOTDEPPATH = --dep-path .
+
+# Built-in application info
+
+APPNAME = cpuhog
+PRIORITY = SCHED_PRIORITY_LOW
+STACKSIZE = 1024
+
+# Common build
+
+VPATH =
+
+all: .built
+.PHONY: clean depend distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	$(call ARCHIVE, $(BIN), $(OBJS))
+	@touch .built
+
+ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
+$(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat: $(DEPCONFIG) Makefile
+	$(call REGISTER,$(APPNAME),$(PRIORITY),$(STACKSIZE),$(APPNAME)_main)
+
+context: $(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat
+else
+context:
+endif
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	$(call DELFILE, .built)
+	$(call CLEAN)
+
+distclean: clean
+	$(call DELFILE, Make.dep)
+	$(call DELFILE, .depend)
+
+-include Make.dep

examples/cpuhog/cpuhog_main.c

@@ -0,0 +1,163 @@
+/****************************************************************************
+ * examples/cpuhog/cpuhog_main.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 <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <nuttx/clock.h>
+#include <nuttx/arch.h>
+#include <semaphore.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define CPUHOG_FIFO_FNAME "/dev/cpuhogfifo"
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct state_s
+{
+  volatile bool initialized;
+  sem_t sem;
+  int count;
+} g_state;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int cpuhog_main(int argc, char *argv[])
+{
+  int id = -1;
+  char buf[256];
+  int fd = -1;
+
+  if (!g_state.initialized)
+    {
+      sem_init(&g_state.sem, 0, 1);
+      mkfifo(CPUHOG_FIFO_FNAME, 0666);
+      g_state.count = 0;
+      g_state.initialized = true;
+      printf("cpuhog initialized\n");
+    }
+
+  while(1)
+    {
+      /* To test semaphore interaction (debugging system crashes...) */
+
+      while (sem_wait(&g_state.sem) != 0)
+        {
+          ASSERT(errno == EINTR);
+        }
+
+      /* Burn some inside semlock */
+
+      up_udelay(3000);
+      sem_post(&g_state.sem);
+
+      /* Unassigned */
+
+      if (id == -1)
+        {
+          id = g_state.count++;
+          printf("cpuhog %d", id);
+          if (id == 0)
+            {
+              printf(": consumer\n");
+              fd = open(CPUHOG_FIFO_FNAME, O_RDONLY);
+            }
+          else if (id == 1)
+            {
+              printf(": producer\n");
+              fd = open(CPUHOG_FIFO_FNAME, O_WRONLY);
+            }
+          else
+            {
+              printf("\n");
+            }
+        }
+
+      /* Consumer */
+
+      else if (id == 0)
+        {
+          if (read(fd, buf, sizeof(buf)) > 0)
+            {
+              printf("-");
+            }
+          else
+            {
+              perror("fifo: ");
+            }
+        }
+
+      /* Producer */
+
+      else if (id == 1)
+        {
+          if (write(fd, buf, sizeof(buf)) > 0)
+            {
+              printf("+");
+            }
+          else
+            {
+              perror("fifo: ");
+            }
+        }
+
+      /* Otherwise just a cpu burner */
+
+      else
+        {
+          /* Burn some outside semlock */
+
+          up_udelay(3000);
+        }
+    }
+
+  return 0;
+}

examples/serialblaster/.gitignore

@@ -0,0 +1,11 @@
+/Make.dep
+/.depend
+/.built
+/*.asm
+/*.obj
+/*.rel
+/*.lst
+/*.sym
+/*.adb
+/*.lib
+/*.src

examples/serialblaster/Kconfig

@@ -0,0 +1,13 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config EXAMPLES_SERIALBLASTER
+    bool "Serial Blaster example"
+    default n
+    ---help---
+        Enable the serial blaster example
+
+if EXAMPLES_SERIALBLASTER
+endif

examples/serialblaster/Makefile

@@ -0,0 +1,109 @@
+############################################################################
+# apps/examples/serialblaster/Makefile
+#
+#   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.
+#
+############################################################################
+
+-include $(TOPDIR)/.config
+-include $(TOPDIR)/Make.defs
+include $(APPDIR)/Make.defs
+
+# For testing: Blast canned characters at a designated serial port
+
+ASRCS =
+CSRCS = serialblaster_main.c
+
+AOBJS = $(ASRCS:.S=$(OBJEXT))
+COBJS = $(CSRCS:.c=$(OBJEXT))
+
+SRCS = $(ASRCS) $(CSRCS)
+OBJS = $(AOBJS) $(COBJS)
+
+ifeq ($(CONFIG_WINDOWS_NATIVE),y)
+  BIN = ..\..\libapps$(LIBEXT)
+else
+ifeq ($(WINTOOL),y)
+  BIN = ..\\..\\libapps$(LIBEXT)
+else
+  BIN = ../../libapps$(LIBEXT)
+endif
+endif
+
+ROOTDEPPATH = --dep-path .
+
+# Built-in application info
+
+APPNAME = serialblaster
+PRIORITY = SCHED_PRIORITY_DEFAULT
+STACKSIZE = 2048
+
+# Common build
+
+VPATH =
+
+all: .built
+.PHONY: clean depend distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	$(call ARCHIVE, $(BIN), $(OBJS))
+	@touch .built
+
+ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
+$(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat: $(DEPCONFIG) Makefile
+	$(call REGISTER,$(APPNAME),$(PRIORITY),$(STACKSIZE),$(APPNAME)_main)
+
+context: $(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat
+else
+context:
+endif
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	$(call DELFILE, .built)
+	$(call CLEAN)
+
+distclean: clean
+	$(call DELFILE, Make.dep)
+	$(call DELFILE, .depend)
+
+-include Make.dep

examples/serialblaster/serialblaster_main.c

@@ -0,0 +1,81 @@
+/****************************************************************************
+ * examples/serialblaster/serialblaster_main.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 <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <nuttx/clock.h>
+
+#include <nuttx/fs/fs.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define BUFFERED_IO
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const char s[] = "abcdefghijklmnopqrstuvwxyz";
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * serloop_main
+ ****************************************************************************/
+
+int serialblaster_main(int argc, char *argv[])
+{
+  while(1)
+    {
+#ifdef BUFFERED_IO
+      int ret = fputs(s, stdout);
+#else
+      int ret = write(1, s, sizeof(s)-1);
+#endif
+    }
+
+  return 0;
+}