Merge branch 'master' into nuttx-merge-5447

9 files changed, 850 insertions, 0 deletions

diff --git a/nuttx/libc/math/Make.defs b/nuttx/libc/math/Make.defs
new file mode 100644
index 000000000..ece25f4e5
--- /dev/null
+++ b/nuttx/libc/math/Make.defs
@@ -0,0 +1,62 @@
+############################################################################
+# libc/math/Make.defs
+#
+#   Copyright (C) 2012 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.
+#
+############################################################################
+
+ifeq ($(CONFIG_LIBM),y)
+
+# Add the floating point math C files to the build
+
+CSRCS += lib_acosf.c lib_asinf.c lib_atan2f.c lib_atanf.c lib_ceilf.c lib_cosf.c
+CSRCS += lib_coshf.c  lib_expf.c lib_fabsf.c lib_floorf.c lib_fmodf.c lib_frexpf.c
+CSRCS += lib_ldexpf.c lib_logf.c lib_log10f.c lib_log2f.c lib_modff.c lib_powf.c
+CSRCS += lib_roundf.c lib_sinf.c lib_sinhf.c lib_sqrtf.c lib_tanf.c lib_tanhf.c
+
+CSRCS += lib_acos.c lib_asin.c lib_atan.c lib_atan2.c lib_ceil.c lib_cos.c
+CSRCS += lib_cosh.c lib_exp.c lib_fabs.c lib_floor.c lib_fmod.c lib_frexp.c
+CSRCS += lib_ldexp.c lib_log.c lib_log10.c lib_log2.c lib_modf.c lib_pow.c
+CSRCS += lib_round.c lib_sin.c lib_sinh.c lib_sqrt.c lib_tan.c lib_tanh.c
+
+CSRCS += lib_acosl.c lib_asinl.c lib_atan2l.c lib_atanl.c lib_ceill.c lib_cosl.c
+CSRCS += lib_coshl.c lib_expl.c lib_fabsl.c lib_floorl.c lib_fmodl.c lib_frexpl.c
+CSRCS += lib_ldexpl.c lib_logl.c lib_log10l.c lib_log2l.c lib_modfl.c lib_powl.c
+CSRCS += lib_roundl.c lib_sinl.c lib_sinhl.c lib_sqrtl.c lib_tanl.c lib_tanhl.c
+
+CSRCS += lib_libexpi.c lib_libsqrtapprox.c
+
+# Add the floating point math directory to the build
+
+DEPPATH += --dep-path math
+VPATH += :math
+
+endif
diff --git a/nuttx/libc/math/lib_round.c b/nuttx/libc/math/lib_round.c
new file mode 100644
index 000000000..6191cee5b
--- /dev/null
+++ b/nuttx/libc/math/lib_round.c
@@ -0,0 +1,40 @@
+/************************************************************************
+ * lib/math/lib_round.c
+ *
+ * This file is a part of NuttX:
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *             (C) 2012 Petteri Aimonen <jpa@nx.mail.kapsi.fi>
+ *
+ ************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_DOUBLE
+double round(double x)
+{
+  double f = modf(x, &x);
+  if (x <= 0.0 && f <= -0.5)
+    {
+      x -= 1.0;
+    }
+  
+  if (x >= 0.0 && f >= 0.5)
+    {
+      x += 1.0;
+    }
+
+  return x;
+}
+#endif
diff --git a/nuttx/libc/math/lib_roundf.c b/nuttx/libc/math/lib_roundf.c
new file mode 100644
index 000000000..145cf3df6
--- /dev/null
+++ b/nuttx/libc/math/lib_roundf.c
@@ -0,0 +1,38 @@
+/************************************************************************
+ * lib/math/lib_roundf.c
+ *
+ * This file is a part of NuttX:
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *             (C) 2012 Petteri Aimonen <jpa@nx.mail.kapsi.fi>
+ *
+ ************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+float roundf(float x)
+{
+  float f = modff(x, &x);
+  if (x <= 0.0f && f <= -0.5f)
+    {
+      x -= 1.0f;
+    }
+  
+  if (x >= 0.0f && f >= 0.5f)
+    {
+      x += 1.0f;
+    }
+
+  return x;
+}
diff --git a/nuttx/libc/math/lib_roundl.c b/nuttx/libc/math/lib_roundl.c
new file mode 100644
index 000000000..b2ddba670
--- /dev/null
+++ b/nuttx/libc/math/lib_roundl.c
@@ -0,0 +1,40 @@
+/************************************************************************
+ * lib/math/lib_round.c
+ *
+ * This file is a part of NuttX:
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *             (C) 2012 Petteri Aimonen <jpa@nx.mail.kapsi.fi>
+ *
+ ************************************************************************/
+
+/************************************************************************
+ * Included Files
+ ************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <math.h>
+
+/************************************************************************
+ * Public Functions
+ ************************************************************************/
+
+#ifdef CONFIG_HAVE_LONG_DOUBLE
+long double roundl(long double x)
+{
+  long double f = modfl(x, &x);
+  if (x <= 0.0 && f <= -0.5)
+    {
+      x -= 1.0;
+    }
+  
+  if (x >= 0.0 && f >= 0.5)
+    {
+      x += 1.0;
+    }
+
+  return x;
+}
+#endif
diff --git a/nuttx/libc/stdlib/lib_rand.c b/nuttx/libc/stdlib/lib_rand.c
new file mode 100644
index 000000000..453a4537a
--- /dev/null
+++ b/nuttx/libc/stdlib/lib_rand.c
@@ -0,0 +1,277 @@
+/****************************************************************************
+ * libc/stdlib/lib_rand.c
+ *
+ *   Copyright (C) 2007, 2011 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 <sys/types.h>
+#include <stdlib.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* First, second, and thired order congruential generators are supported */
+
+#ifndef CONFIG_LIB_RAND_ORDER
+#  define CONFIG_LIB_RAND_ORDER 1
+#endif
+
+#if CONFIG_LIB_RAND_ORDER > 3
+#  undef CONFIG_LIB_RAND_ORDER
+#  define CONFIG_LIB_RAND_ORDER 3
+#endif
+
+/* Values needed by the random number generator */
+
+#define RND1_CONSTK  470001
+#define RND1_CONSTP  999563
+#define RND2_CONSTK1 366528
+#define RND2_CONSTK2 508531
+#define RND2_CONSTP  998917
+#define RND3_CONSTK1 360137
+#define RND3_CONSTK2 519815
+#define RND3_CONSTK3 616087
+#define RND3_CONSTP  997783
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static unsigned int nrand(unsigned int nLimit);
+
+/* First order congruential generators */
+
+static inline unsigned long fgenerate1(void);
+#if (CONFIG_LIB_RAND_ORDER == 1)
+static double_t frand1(void);
+#endif
+
+/* Second order congruential generators */
+
+#if (CONFIG_LIB_RAND_ORDER > 1)
+static inline unsigned long fgenerate2(void);
+#if (CONFIG_LIB_RAND_ORDER == 2)
+static double_t frand2(void);
+#endif
+
+/* Third order congruential generators */
+
+#if (CONFIG_LIB_RAND_ORDER > 2)
+static inline unsigned long fgenerate3(void);
+static double_t frand3(void);
+#endif
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static unsigned long g_randint1;
+#if (CONFIG_LIB_RAND_ORDER > 1)
+static unsigned long g_randint2;
+#if (CONFIG_LIB_RAND_ORDER > 2)
+static unsigned long g_randint3;
+#endif
+#endif
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static unsigned int nrand(unsigned int nLimit)
+{
+  unsigned long result;
+  double_t ratio;
+
+  /* Loop to be sure a legal random number is generated */
+
+  do
+    {
+      /* Get a random integer in the requested range */
+
+#if (CONFIG_LIB_RAND_ORDER == 1)
+      ratio = frand1();
+#elif (CONFIG_LIB_RAND_ORDER == 2)
+      ratio = frand2();
+#else /* if (CONFIG_LIB_RAND_ORDER > 2) */
+      ratio = frand3();
+#endif
+
+      /* Then, produce the return-able value */
+
+      result = (unsigned long)(((double_t)nLimit) * ratio);
+    }
+  while (result >= (unsigned long)nLimit);
+
+  return (unsigned int)result;
+}
+
+/* First order congruential generators */
+
+static inline unsigned long fgenerate1(void)
+{
+  unsigned long randint;
+
+  /* First order congruential generator.  One may be added to the result of the
+   * generated value to avoid the value zero.  This would be fatal for the
+   * first order random number generator.
+   */
+
+  randint    = (RND1_CONSTK * g_randint1) % RND1_CONSTP;
+  g_randint1 = (randint == 0 ? 1 : randint);
+  return randint;
+}
+
+#if (CONFIG_LIB_RAND_ORDER == 1)
+static double_t frand1(void)
+{
+  /* First order congruential generator. */
+
+  unsigned long randint = fgenerate1();
+
+  /* Construct an floating point value in the range from 0.0 up to 1.0 */
+
+  return ((double_t)randint) / ((double_t)RND1_CONSTP);
+}
+#endif
+
+/* Second order congruential generators */
+
+#if (CONFIG_LIB_RAND_ORDER > 1)
+static inline unsigned long fgenerate2(void)
+{
+  unsigned long randint;
+
+  /* Second order congruential generator. */
+
+  randint    = (RND2_CONSTK1 * g_randint1 +
+                RND2_CONSTK2 * g_randint2) % RND2_CONSTP;
+
+  g_randint2 = g_randint1;
+  g_randint1 = randint;
+
+  /* We cannot permit both values to become zero.  That would be fatal for the
+   * second order random number generator.
+   */
+
+  if (g_randint2 == 0 && g_randint1 == 0)
+    {
+      g_randint2 = 1;
+    }
+
+  return randint;
+}
+
+#if (CONFIG_LIB_RAND_ORDER == 2)
+static double_t frand2(void)
+{
+  /* Second order congruential generator */
+
+  unsigned long randint = fgenerate2();
+
+  /* Construct an floating point value in the range from 0.0 up to 1.0 */
+
+  return ((double_t)randint) / ((double_t)RND2_CONSTP);
+}
+#endif
+
+/* Third order congruential generators */
+
+#if (CONFIG_LIB_RAND_ORDER > 2)
+static inline unsigned long fgenerate3(void)
+{
+  unsigned long randint;
+
+  /* Third order congruential generator. */
+
+  randint    = (RND3_CONSTK1 * g_randint1 +
+                RND3_CONSTK2 * g_randint2 +
+                RND3_CONSTK2 * g_randint3) % RND3_CONSTP;
+
+  g_randint3 = g_randint2;
+  g_randint2 = g_randint1;
+  g_randint1 = randint;
+
+  /* We cannot permit all three values to become zero.  That would be fatal for the
+   * third order random number generator.
+   */
+
+  if (g_randint3 == 0 && g_randint2 == 0 && g_randint1 == 0)
+    {
+      g_randint3 = 1;
+    }
+
+  return randint;
+}
+
+static double_t frand3(void)
+{
+  /* Third order congruential generator */
+
+  unsigned long randint = fgenerate3();
+
+  /* Construct an floating point value in the range from 0.0 up to 1.0 */
+
+  return ((double_t)randint) / ((double_t)RND3_CONSTP);
+}
+#endif
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function:  srand, rand
+ ****************************************************************************/
+
+void srand(unsigned int seed)
+{
+  g_randint1 = seed;
+#if (CONFIG_LIB_RAND_ORDER > 1)
+  g_randint2 = seed;
+  (void)fgenerate1();
+#if (CONFIG_LIB_RAND_ORDER > 2)
+  g_randint3 = seed;
+  (void)fgenerate2();
+#endif
+#endif
+}
+
+int rand(void)
+{
+  return (int)nrand(32768);
+}
diff --git a/nuttx/libc/string/lib_memcmp.c b/nuttx/libc/string/lib_memcmp.c
new file mode 100644
index 000000000..5434bb847
--- /dev/null
+++ b/nuttx/libc/string/lib_memcmp.c
@@ -0,0 +1,74 @@
+/************************************************************
+ * libc/string/lib_memcmp.c
+ *
+ *   Copyright (C) 2007, 2011-2012 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.
+ *
+ ************************************************************/
+
+/************************************************************
+ * Compilation Switches
+ ************************************************************/
+
+/************************************************************
+ * Included Files
+ ************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <string.h>
+
+/************************************************************
+ * Global Functions
+ ************************************************************/
+
+#ifndef CONFIG_ARCH_MEMCMP
+int memcmp(FAR const void *s1, FAR const void *s2, size_t n)
+{
+  unsigned char *p1 = (unsigned char *)s1;
+  unsigned char *p2 = (unsigned char *)s2;
+
+  while (n-- > 0)
+    {
+      if (*p1 < *p2)
+        {
+          return -1;
+        }
+      else if (*p1 > *p2)
+        {
+          return 1;
+        }
+
+      p1++;
+      p2++;
+    }
+  return 0;
+}
+#endif
diff --git a/nuttx/libc/string/lib_memmove.c b/nuttx/libc/string/lib_memmove.c
new file mode 100644
index 000000000..cc8317223
--- /dev/null
+++ b/nuttx/libc/string/lib_memmove.c
@@ -0,0 +1,77 @@
+/************************************************************
+ * libc/string/lib_memmove.c
+ *
+ *   Copyright (C) 2007, 2011 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.
+ *
+ ************************************************************/
+
+/************************************************************
+ * Compilation Switches
+ ************************************************************/
+
+/************************************************************
+ * Included Files
+ ************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <string.h>
+
+/************************************************************
+ * Global Functions
+ ************************************************************/
+
+#ifndef CONFIG_ARCH_MEMMOVE
+FAR void *memmove(FAR void *dest, FAR const void *src, size_t count)
+{
+  char *tmp, *s;
+  if (dest <= src)
+    {
+      tmp = (char*) dest;
+      s   = (char*) src;
+      while (count--)
+        {
+	  *tmp++ = *s++;
+        }
+    }
+  else
+    {
+      tmp = (char*) dest + count;
+      s   = (char*) src + count;
+      while (count--)
+        {
+	  *--tmp = *--s;
+        }
+    }
+
+  return dest;
+}
+#endif
diff --git a/nuttx/libc/string/lib_strcasestr.c b/nuttx/libc/string/lib_strcasestr.c
new file mode 100644
index 000000000..7f17a686d
--- /dev/null
+++ b/nuttx/libc/string/lib_strcasestr.c
@@ -0,0 +1,136 @@
+/****************************************************************************
+ * libc/string/lib_strstr.c
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use str 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 str binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer str
+ *    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 <string.h>
+#include <ctype.h>
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static FAR char *strcasechr(FAR const char *s, int uc)
+{
+  register char ch;
+
+  if (s)
+    {
+      for (; *s; s++)
+        {
+          ch = *s;
+          if (toupper(ch) == uc)
+            {
+              return (FAR char*)s;
+            }
+        }
+    }
+
+  return NULL;
+}
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+FAR char *strcasestr(FAR const char *str, FAR const char *substr)
+{
+  const char *candidate;  /* Candidate in str with matching start character */
+  char         ch;        /* First character of the substring */
+  int          len;       /* The length of the substring */
+
+  /* Special case the empty substring */
+
+  len = strlen(substr);
+  ch  = *substr;
+
+  if (!ch)
+    {
+      /* We'll say that an empty substring matches at the beginning of
+       * the string
+       */
+
+      return (char*)str;
+    }
+
+  /* Search for the substring */
+
+  candidate = str;
+  ch        = toupper(ch);
+
+  for (;;)
+    {
+      /* strcasechr() will return a pointer to the next occurrence of the
+       * character ch in the string (ignoring case)
+       */
+
+      candidate = strcasechr(candidate, ch);
+      if (!candidate || strlen(candidate) < len)
+        {
+           /* First character of the substring does not appear in the string
+            * or the remainder of the string is not long enough to contain the
+            * substring.
+            */
+
+           return NULL;
+        }
+
+      /* Check if this is the beginning of a matching substring (ignoring case) */
+
+      if (strncasecmp(candidate, substr, len) == 0)
+        {
+           /* Yes.. return the pointer to the first occurrence of the matching
+            * substring.
+            */
+
+           return (char*)candidate;
+        }
+
+      /* No, find the next candidate after this one */
+
+      candidate++;
+    }
+
+  /* Won't get here, but some compilers might complain.  Others might complain
+   * about this code being unreachable too.
+   */
+
+  return NULL;
+}
+
diff --git a/nuttx/libc/string/lib_strstr.c b/nuttx/libc/string/lib_strstr.c
new file mode 100644
index 000000000..7a60a680d
--- /dev/null
+++ b/nuttx/libc/string/lib_strstr.c
@@ -0,0 +1,106 @@
+/****************************************************************************
+ * libc/string/lib_strstr.c
+ *
+ *   Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use str 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 str binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer str
+ *    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 <string.h>
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+char *strstr(const char *str, const char *substr)
+{
+  const char *candidate;  /* Candidate in str with matching start character */
+  char         ch;        /* First character of the substring */
+  int          len;       /* The length of the substring */
+
+  /* Special case the empty substring */
+
+  len = strlen(substr);
+  ch  = *substr;
+
+  if (!ch)
+    {
+      /* We'll say that an empty substring matches at the beginning of
+       * the string
+       */
+
+      return (char*)str;
+    }
+
+  /* Search for the substring */
+
+  candidate = str;
+  for (;;)
+    {
+      /* strchr() will return a pointer to the next occurrence of the
+       * character ch in the string
+       */
+
+      candidate = strchr(candidate, ch);
+      if (!candidate || strlen(candidate) < len)
+        {
+           /* First character of the substring does not appear in the string
+            * or the remainder of the string is not long enough to contain the
+            * substring.
+            */
+
+           return NULL;
+        }
+
+      /* Check if this is the beginning of a matching substring */
+
+      if (strncmp(candidate, substr, len) == 0)
+        {
+           return (char*)candidate;
+        }
+
+      /* No, find the next candidate after this one */
+
+      candidate++;
+    }
+
+  /* Won't get here, but some compilers might complain.  Other compilers
+   * might complain about this code being unreachable too.
+   */
+
+  return NULL;
+}
+