Merge branch 'master' of github.com:PX4/Firmware into px4io-i2c

10 files changed, 1796 insertions, 0 deletions

diff --git a/nuttx/binfmt/libelf/Kconfig b/nuttx/binfmt/libelf/Kconfig
new file mode 100644
index 000000000..f6f579276
--- /dev/null
+++ b/nuttx/binfmt/libelf/Kconfig
@@ -0,0 +1,40 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config ELF_ALIGN_LOG2
+	int "Log2 Section Alignment"
+	default 2
+	---help---
+		Align all sections to this Log2 value:  0->1, 1->2, 2->4, etc.
+
+config ELF_STACKSIZE
+	int "ELF Stack Size"
+	default 2048
+	---help---
+		This is the default stack size that will will be used when starting ELF binaries.
+
+config ELF_BUFFERSIZE
+	int "ELF I/O Buffer Size"
+	default 128
+	---help---
+		This is an I/O buffer that is used to access the ELF file.  Variable length items
+		will need to be read (such as symbol names).  This is really just this initial
+		size of the buffer; it will be reallocated as necessary to hold large symbol
+		names).  Default: 128
+
+config ELF_BUFFERINCR
+	int "ELF I/O Buffer Realloc Increment"
+	default 32
+	---help---
+		This is an I/O buffer that is used to access the ELF file.  Variable length items
+		will need to be read (such as symbol names).  This value specifies the size
+		increment to use each time the buffer is reallocated.  Default: 32
+
+config ELF_DUMPBUFFER
+	bool "Dump ELF buffers"
+	default n
+	depends on DEBUG && DEBUG_VERBOSE
+	---help---
+		Dump various ELF buffers for debug purposes
diff --git a/nuttx/binfmt/libelf/gnu-elf.ld b/nuttx/binfmt/libelf/gnu-elf.ld
new file mode 100644
index 000000000..b2a3dc113
--- /dev/null
+++ b/nuttx/binfmt/libelf/gnu-elf.ld
@@ -0,0 +1,129 @@
+/****************************************************************************
+ * binfmt/libelf/gnu-elf.ld
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+SECTIONS
+{
+  .text 0x00000000 :
+    {
+      _stext = . ;
+      *(.text)
+      *(.text.*)
+      *(.gnu.warning)
+      *(.stub)
+      *(.glue_7)
+      *(.glue_7t)
+      *(.jcr)
+
+      /* C++ support:  The .init and .fini sections contain specific logic
+       * to manage static constructors and destructors.
+       */
+
+      *(.gnu.linkonce.t.*)
+      *(.init)             /* Old ABI */
+      *(.fini)             /* Old ABI */
+      _etext = . ;
+    }
+
+  .rodata :
+    {
+      _srodata = . ;
+      *(.rodata)
+      *(.rodata1)
+      *(.rodata.*)
+      *(.gnu.linkonce.r*)
+      _erodata = . ;
+    }
+
+  .data :
+    {
+      _sdata = . ;
+      *(.data)
+      *(.data1)
+      *(.data.*)
+      *(.gnu.linkonce.d*)
+      _edata = . ;
+    }
+
+  /* C++ support. For each global and static local C++ object,
+   * GCC creates a small subroutine to construct the object. Pointers
+   * to these routines (not the routines themselves) are stored as
+   * simple, linear arrays in the .ctors section of the object file.
+   * Similarly, pointers to global/static destructor routines are
+   * stored in .dtors.
+   */
+
+  .ctors :
+    {
+      _sctors = . ;
+      *(.ctors)       /* Old ABI:  Unallocated */
+      *(.init_array)  /* New ABI:  Allocated */
+      _edtors = . ;
+    }
+
+  .dtors :
+    {
+      _sdtors = . ;
+      *(.dtors)       /* Old ABI:  Unallocated */
+      *(.fini_array)  /* New ABI:  Allocated */
+      _edtors = . ;
+    }
+
+  .bss :
+    {
+      _sbss = . ;
+      *(.bss)
+      *(.bss.*)
+      *(.sbss)
+      *(.sbss.*)
+      *(.gnu.linkonce.b*)
+      *(COMMON)
+      _ebss = . ;
+    }
+
+    /* Stabs debugging sections.    */
+
+    .stab 0 : { *(.stab) }
+    .stabstr 0 : { *(.stabstr) }
+    .stab.excl 0 : { *(.stab.excl) }
+    .stab.exclstr 0 : { *(.stab.exclstr) }
+    .stab.index 0 : { *(.stab.index) }
+    .stab.indexstr 0 : { *(.stab.indexstr) }
+    .comment 0 : { *(.comment) }
+    .debug_abbrev 0 : { *(.debug_abbrev) }
+    .debug_info 0 : { *(.debug_info) }
+    .debug_line 0 : { *(.debug_line) }
+    .debug_pubnames 0 : { *(.debug_pubnames) }
+    .debug_aranges 0 : { *(.debug_aranges) }
+}
diff --git a/nuttx/binfmt/libelf/libelf_ctors.c b/nuttx/binfmt/libelf/libelf_ctors.c
new file mode 100644
index 000000000..20f1256e2
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_ctors.c
@@ -0,0 +1,215 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_ctors.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+#ifdef CONFIG_BINFMT_CONSTRUCTORS
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_loadctors
+ *
+ * Description:
+ *  Load pointers to static constructors into an in-memory array.
+ *
+ * Input Parameters:
+ *   loadinfo - Load state information
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo)
+{
+  FAR Elf32_Shdr *shdr;
+  size_t ctorsize;
+  int ctoridx;
+  int ret;
+  int i;
+
+  DEBUGASSERT(loadinfo->ctors == NULL);
+
+  /* Allocate an I/O buffer if necessary.  This buffer is used by
+   * elf_sectname() to accumulate the variable length symbol name.
+   */
+
+  ret = elf_allocbuffer(loadinfo);
+  if (ret < 0)
+    {
+      bdbg("elf_allocbuffer failed: %d\n", ret);
+      return -ENOMEM;
+    }
+
+  /* Find the index to the section named ".ctors."  NOTE:  On old ABI system,
+   * .ctors is the name of the section containing the list of constructors;
+   * On newer systems, the similar section is called .init_array.  It is 
+   * expected that the linker script will force the section name to be ".ctors"
+   * in either case.
+   */
+
+  ctoridx = elf_findsection(loadinfo, ".ctors");
+  if (ctoridx < 0)
+    {
+      /* This may not be a failure.  -ENOENT indicates that the file has no
+       * static constructor section.
+       */
+
+      bvdbg("elf_findsection .ctors section failed: %d\n", ctoridx);
+      return ret == -ENOENT ? OK : ret;
+    }
+
+  /* Now we can get a pointer to the .ctor section in the section header
+   * table.
+   */
+
+  shdr = &loadinfo->shdr[ctoridx];
+
+  /* Get the size of the .ctor section and the number of constructors that
+   * will need to be called.
+   */
+
+  ctorsize         = shdr->sh_size;
+  loadinfo->nctors = ctorsize / sizeof(binfmt_ctor_t);
+
+  bvdbg("ctoridx=%d ctorsize=%d sizeof(binfmt_ctor_t)=%d nctors=%d\n",
+        ctoridx, ctorsize,  sizeof(binfmt_ctor_t), loadinfo->nctors);
+
+  /* Check if there are any constructors.  It is not an error if there
+   * are none.
+   */
+
+  if (loadinfo->nctors > 0)
+    {
+      /* Check an assumption that we made above */
+
+      DEBUGASSERT(shdr->sh_size == loadinfo->nctors * sizeof(binfmt_ctor_t));
+
+      /* In the old ABI, the .ctors section is not allocated.  In that case,
+       * we need to allocate memory to hold the .ctors and then copy the
+       * from the file into the allocated memory.
+       *
+       * SHF_ALLOC indicates that the section requires memory during
+       * execution.
+       */
+
+      if ((shdr->sh_flags & SHF_ALLOC) == 0)
+        {
+          /* Allocate memory to hold a copy of the .ctor section */
+
+          loadinfo->ctoralloc = (binfmt_ctor_t*)kmalloc(ctorsize);
+          if (!loadinfo->ctoralloc)
+            {
+              bdbg("Failed to allocate memory for .ctors\n");
+              return -ENOMEM;
+            }
+
+          loadinfo->ctors = (binfmt_ctor_t *)loadinfo->ctoralloc;
+
+          /* Read the section header table into memory */
+
+          ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->ctors, ctorsize,
+                         shdr->sh_offset);
+          if (ret < 0)
+            {
+              bdbg("Failed to allocate .ctors: %d\n", ret);
+              return ret;
+            }
+
+          /* Fix up all of the .ctor addresses.  Since the addresses
+           * do not lie in allocated memory, there will be no relocation
+           * section for them.
+           */
+
+          for (i = 0; i < loadinfo->nctors; i++)
+            {
+              FAR uintptr_t *ptr = (uintptr_t *)((FAR void *)(&loadinfo->ctors)[i]);
+
+              bvdbg("ctor %d: %08lx + %08lx = %08lx\n",
+                    i, *ptr, loadinfo->elfalloc, *ptr + loadinfo->elfalloc);
+
+              *ptr += loadinfo->elfalloc;
+            }
+        }
+      else
+        {
+
+          /* Save the address of the .ctors (actually, .init_array) where it was
+           * loaded into memory.  Since the .ctors lie in allocated memory, they
+           * will be relocated via the normal mechanism.
+           */
+ 
+          loadinfo->ctors = (binfmt_ctor_t*)shdr->sh_addr;
+        }
+    }
+
+  return OK;
+}
+
+#endif /* CONFIG_BINFMT_CONSTRUCTORS */
diff --git a/nuttx/binfmt/libelf/libelf_dtors.c b/nuttx/binfmt/libelf/libelf_dtors.c
new file mode 100644
index 000000000..c0c73a337
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_dtors.c
@@ -0,0 +1,215 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_dtors.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+#ifdef CONFIG_BINFMT_CONSTRUCTORS
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_loaddtors
+ *
+ * Description:
+ *  Load pointers to static destructors into an in-memory array.
+ *
+ * Input Parameters:
+ *   loadinfo - Load state information
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_loaddtors(FAR struct elf_loadinfo_s *loadinfo)
+{
+  FAR Elf32_Shdr *shdr;
+  size_t dtorsize;
+  int dtoridx;
+  int ret;
+  int i;
+
+  DEBUGASSERT(loadinfo->dtors == NULL);
+
+  /* Allocate an I/O buffer if necessary.  This buffer is used by
+   * elf_sectname() to accumulate the variable length symbol name.
+   */
+
+  ret = elf_allocbuffer(loadinfo);
+  if (ret < 0)
+    {
+      bdbg("elf_allocbuffer failed: %d\n", ret);
+      return -ENOMEM;
+    }
+
+  /* Find the index to the section named ".dtors."  NOTE:  On old ABI system,
+   * .dtors is the name of the section containing the list of destructors;
+   * On newer systems, the similar section is called .fini_array.  It is 
+   * expected that the linker script will force the section name to be ".dtors"
+   * in either case.
+   */
+
+  dtoridx = elf_findsection(loadinfo, ".dtors");
+  if (dtoridx < 0)
+    {
+      /* This may not be a failure.  -ENOENT indicates that the file has no
+       * static destructor section.
+       */
+
+      bvdbg("elf_findsection .dtors section failed: %d\n", dtoridx);
+      return ret == -ENOENT ? OK : ret;
+    }
+
+  /* Now we can get a pointer to the .dtor section in the section header
+   * table.
+   */
+
+  shdr = &loadinfo->shdr[dtoridx];
+
+  /* Get the size of the .dtor section and the number of destructors that
+   * will need to be called.
+   */
+
+  dtorsize         = shdr->sh_size;
+  loadinfo->ndtors = dtorsize / sizeof(binfmt_dtor_t);
+
+  bvdbg("dtoridx=%d dtorsize=%d sizeof(binfmt_dtor_t)=%d ndtors=%d\n",
+        dtoridx, dtorsize,  sizeof(binfmt_dtor_t), loadinfo->ndtors);
+
+  /* Check if there are any destructors.  It is not an error if there
+   * are none.
+   */
+
+  if (loadinfo->ndtors > 0)
+    {
+      /* Check an assumption that we made above */
+
+      DEBUGASSERT(shdr->sh_size == loadinfo->ndtors * sizeof(binfmt_dtor_t));
+
+      /* In the old ABI, the .dtors section is not allocated.  In that case,
+       * we need to allocate memory to hold the .dtors and then copy the
+       * from the file into the allocated memory.
+       *
+       * SHF_ALLOC indicates that the section requires memory during
+       * execution.
+       */
+
+      if ((shdr->sh_flags & SHF_ALLOC) == 0)
+        {
+          /* Allocate memory to hold a copy of the .dtor section */
+
+          loadinfo->ctoralloc = (binfmt_dtor_t*)kmalloc(dtorsize);
+          if (!loadinfo->ctoralloc)
+            {
+              bdbg("Failed to allocate memory for .dtors\n");
+              return -ENOMEM;
+            }
+
+          loadinfo->dtors = (binfmt_dtor_t *)loadinfo->ctoralloc;
+
+          /* Read the section header table into memory */
+
+          ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->dtors, dtorsize,
+                         shdr->sh_offset);
+          if (ret < 0)
+            {
+              bdbg("Failed to allocate .dtors: %d\n", ret);
+              return ret;
+            }
+
+          /* Fix up all of the .dtor addresses.  Since the addresses
+           * do not lie in allocated memory, there will be no relocation
+           * section for them.
+           */
+
+          for (i = 0; i < loadinfo->ndtors; i++)
+            {
+              FAR uintptr_t *ptr = (uintptr_t *)((FAR void *)(&loadinfo->dtors)[i]);
+
+              bvdbg("dtor %d: %08lx + %08lx = %08lx\n",
+                    i, *ptr, loadinfo->elfalloc, *ptr + loadinfo->elfalloc);
+
+              *ptr += loadinfo->elfalloc;
+            }
+        }
+      else
+        {
+
+          /* Save the address of the .dtors (actually, .init_array) where it was
+           * loaded into memory.  Since the .dtors lie in allocated memory, they
+           * will be relocated via the normal mechanism.
+           */
+ 
+          loadinfo->dtors = (binfmt_dtor_t*)shdr->sh_addr;
+        }
+    }
+
+  return OK;
+}
+
+#endif /* CONFIG_BINFMT_CONSTRUCTORS */
diff --git a/nuttx/binfmt/libelf/libelf_init.c b/nuttx/binfmt/libelf/libelf_init.c
new file mode 100644
index 000000000..fa4b7983c
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_init.c
@@ -0,0 +1,202 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_init.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/stat.h>
+
+#include <stdint.h>
+#include <string.h>
+#include <fcntl.h>
+#include <elf32.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/* CONFIG_DEBUG, CONFIG_DEBUG_VERBOSE, and CONFIG_DEBUG_BINFMT have to be
+ * defined or CONFIG_ELF_DUMPBUFFER does nothing.
+ */
+
+#if !defined(CONFIG_DEBUG_VERBOSE) || !defined (CONFIG_DEBUG_BINFMT)
+#  undef CONFIG_ELF_DUMPBUFFER
+#endif
+
+#ifdef CONFIG_ELF_DUMPBUFFER
+# define elf_dumpbuffer(m,b,n) bvdbgdumpbuffer(m,b,n)
+#else
+# define elf_dumpbuffer(m,b,n)
+#endif
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_filelen
+ *
+ * Description:
+ *  Get the size of the ELF file
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+static inline int elf_filelen(FAR struct elf_loadinfo_s *loadinfo,
+                              FAR const char *filename)
+{
+  struct stat buf;
+  int ret;
+
+  /* Get the file stats */
+
+  ret = stat(filename, &buf);
+  if (ret < 0)
+    {
+      int errval = errno;
+      bdbg("Failed to fstat file: %d\n", errval);
+      return -errval;
+    }
+
+  /* Verify that it is a regular file */
+
+  if (!S_ISREG(buf.st_mode))
+    {
+      bdbg("Not a regular file.  mode: %d\n", buf.st_mode);
+      return -ENOENT;
+    }
+
+  /* TODO:  Verify that the file is readable.  Not really important because
+   * we will detect this when we try to open the file read-only.
+   */
+
+  /* Return the size of the file in the loadinfo structure */
+
+  loadinfo->filelen = buf.st_size;
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_init
+ *
+ * Description:
+ *   This function is called to configure the library to process an ELF
+ *   program binary.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_init(FAR const char *filename, FAR struct elf_loadinfo_s *loadinfo)
+{
+  int ret;
+
+  bvdbg("filename: %s loadinfo: %p\n", filename, loadinfo);
+
+  /* Clear the load info structure */
+
+  memset(loadinfo, 0, sizeof(struct elf_loadinfo_s));
+
+  /* Get the length of the file. */
+
+  ret = elf_filelen(loadinfo, filename);
+  if (ret < 0)
+    {
+      bdbg("elf_filelen failed: %d\n", ret);
+      return ret;
+    }
+
+  /* Open the binary file for reading (only) */
+
+  loadinfo->filfd = open(filename, O_RDONLY);
+  if (loadinfo->filfd < 0)
+    {
+      int errval = errno;
+      bdbg("Failed to open ELF binary %s: %d\n", filename, errval);
+      return -errval;      
+    }
+
+  /* Read the ELF ehdr from offset 0 */
+
+  ret = elf_read(loadinfo, (FAR uint8_t*)&loadinfo->ehdr, sizeof(Elf32_Ehdr), 0);
+  if (ret < 0)
+    {
+      bdbg("Failed to read ELF header: %d\n", ret);
+      return ret;
+    }
+
+  elf_dumpbuffer("ELF header", (FAR const uint8_t*)&loadinfo->ehdr, sizeof(Elf32_Ehdr));
+
+  /* Verify the ELF header */
+
+  ret = elf_verifyheader(&loadinfo->ehdr);
+  if (ret <0)
+    {
+      /* This may not be an error because we will be called to attempt loading
+       * EVERY binary.  If elf_verifyheader() does not recognize the ELF header,
+       * it will -ENOEXEC whcih simply informs the system that the file is not an
+       * ELF file.  elf_verifyheader() will return other errors if the ELF header
+       * is not correctly formed.
+       */
+
+      bdbg("Bad ELF header: %d\n", ret);
+      return ret;
+    }
+
+  return OK;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_iobuffer.c b/nuttx/binfmt/libelf/libelf_iobuffer.c
new file mode 100644
index 000000000..ead99ca09
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_iobuffer.c
@@ -0,0 +1,136 @@
+/****************************************************************************
+ * binfmt/libelf/elf_iobuffer.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_allocbuffer
+ *
+ * Description:
+ *   Perform the initial allocation of the I/O buffer, if it has not already
+ *   been allocated.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_allocbuffer(FAR struct elf_loadinfo_s *loadinfo)
+{
+  /* Has a buffer been allocated> */
+
+  if (!loadinfo->iobuffer)
+    {
+      /* No.. allocate one now */
+ 
+      loadinfo->iobuffer = (FAR uint8_t *)kmalloc(CONFIG_ELF_BUFFERSIZE);
+      if (!loadinfo->iobuffer)
+        {
+          bdbg("Failed to allocate an I/O buffer\n");
+          return -ENOMEM;
+        }
+
+      loadinfo->buflen = CONFIG_ELF_BUFFERSIZE;
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: elf_reallocbuffer
+ *
+ * Description:
+ *   Increase the size of I/O buffer by the specified buffer increment.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_reallocbuffer(FAR struct elf_loadinfo_s *loadinfo, size_t increment)
+{
+  FAR void *buffer;
+  size_t newsize;
+
+  /* Get the new size of the allocation */
+
+  newsize = loadinfo->buflen + increment;
+
+  /* And perform the reallocation */
+
+   buffer = krealloc((FAR void *)loadinfo->iobuffer, newsize);
+   if (!buffer)
+    {
+      bdbg("Failed to reallocate the I/O buffer\n");
+      return -ENOMEM;
+    }
+
+  /* Save the new buffer info */
+
+  loadinfo->iobuffer = buffer;
+  loadinfo->buflen   = newsize;
+  return OK;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_sections.c b/nuttx/binfmt/libelf/libelf_sections.c
new file mode 100644
index 000000000..c41793544
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_sections.c
@@ -0,0 +1,284 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_sections.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_sectname
+ *
+ * Description:
+ *   Get the symbol name in loadinfo->iobuffer[].
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+static inline int elf_sectname(FAR struct elf_loadinfo_s *loadinfo,
+                               FAR const Elf32_Shdr *shdr)
+{
+  FAR Elf32_Shdr *shstr;
+  FAR uint8_t *buffer;
+  off_t  offset;
+  size_t readlen;
+  size_t bytesread;
+  int shstrndx;
+  int ret;
+
+  /* Get the section header table index of the entry associated with the
+   * section name string table. If the file has no section name string table,
+   * this member holds the value SH_UNDEF.
+   */
+
+  shstrndx = loadinfo->ehdr.e_shstrndx;
+  if (shstrndx == SHN_UNDEF)
+    {
+      bdbg("No section header string table\n");
+      return -EINVAL;
+    }
+
+  /* Get the section name string table section header */
+
+  shstr = &loadinfo->shdr[shstrndx];
+
+  /* Get the file offset to the string that is the name of the section. This
+   * is the sum of:
+   *
+   *   shstr->sh_offset: The file offset to the first byte of the section
+   *     header string table data.
+   *   shdr->sh_name: The offset to the name of the section in the section
+   *     name table
+   */
+
+  offset = shstr->sh_offset + shdr->sh_name;
+
+  /* Loop until we get the entire section name into memory */
+
+  buffer    = loadinfo->iobuffer;
+  bytesread = 0;
+
+  for (;;)
+    {
+      /* Get the number of bytes to read */
+
+      readlen = loadinfo->buflen - bytesread;
+      if (offset + readlen > loadinfo->filelen)
+        {
+          readlen = loadinfo->filelen - offset;
+          if (readlen <= 0)
+            {
+              bdbg("At end of file\n");
+              return -EINVAL;
+            }
+        }
+
+      /* Read that number of bytes into the array */
+
+      buffer = &loadinfo->iobuffer[bytesread];
+      ret = elf_read(loadinfo, buffer, readlen, offset);
+      if (ret < 0)
+        {
+          bdbg("Failed to read section name\n");
+          return ret;
+        }
+
+      bytesread += readlen;
+
+      /* Did we read the NUL terminator? */
+
+      if (memchr(buffer, '\0', readlen) != NULL)
+        {
+          /* Yes, the buffer contains a NUL terminator. */
+
+          return OK;
+        }
+
+      /* No.. then we have to read more */
+
+      ret = elf_reallocbuffer(loadinfo, CONFIG_ELF_BUFFERINCR);
+      if (ret < 0)
+        {
+          bdbg("elf_reallocbuffer failed: %d\n", ret);
+          return ret;
+        }
+    }
+
+  /* We will not get here */
+
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_loadshdrs
+ *
+ * Description:
+ *   Loads section headers into memory.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_loadshdrs(FAR struct elf_loadinfo_s *loadinfo)
+{
+  size_t shdrsize;
+  int ret;
+
+  DEBUGASSERT(loadinfo->shdr == NULL);
+
+  /* Verify that there are sections */
+
+  if (loadinfo->ehdr.e_shnum < 1)
+    {
+      bdbg("No sections(?)\n");
+      return -EINVAL;
+    }
+
+  /* Get the total size of the section header table */
+
+  shdrsize = (size_t)loadinfo->ehdr.e_shentsize * (size_t)loadinfo->ehdr.e_shnum;
+  if(loadinfo->ehdr.e_shoff + shdrsize > loadinfo->filelen)
+    {
+      bdbg("Insufficent space in file for section header table\n");
+      return -ESPIPE;
+    }
+
+  /* Allocate memory to hold a working copy of the sector header table */
+
+  loadinfo->shdr = (FAR Elf32_Shdr*)kmalloc(shdrsize);
+  if (!loadinfo->shdr)
+    {
+      bdbg("Failed to allocate the section header table. Size: %ld\n", (long)shdrsize);
+      return -ENOMEM;
+    }
+
+  /* Read the section header table into memory */
+
+  ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->shdr, shdrsize, loadinfo->ehdr.e_shoff);
+  if (ret < 0)
+    {
+      bdbg("Failed to read section header table: %d\n", ret);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: elf_findsection
+ *
+ * Description:
+ *   A section by its name.
+ *
+ * Input Parameters:
+ *   loadinfo - Load state information
+ *   sectname - Name of the section to find
+ *
+ * Returned Value:
+ *   On success, the index to the section is returned; A negated errno value
+ *   is returned on failure.
+ *
+ ****************************************************************************/
+
+int elf_findsection(FAR struct elf_loadinfo_s *loadinfo,
+                    FAR const char *sectname)
+{
+  FAR const Elf32_Shdr *shdr;
+  int ret;
+  int i;
+
+  /* Search through the shdr[] array in loadinfo for a section named 'sectname' */
+
+  for (i = 0; i < loadinfo->ehdr.e_shnum; i++)
+    {
+      /* Get the name of this section */
+
+      shdr = &loadinfo->shdr[i];
+      ret  = elf_sectname(loadinfo, shdr);
+      if (ret < 0)
+        {
+          bdbg("elf_sectname failed: %d\n", ret);
+          return ret;
+        }
+ 
+      /* Check if the name of this section is 'sectname' */
+
+      bvdbg("%d. Comparing \"%s\" and .\"%s\"\n",
+            i, loadinfo->iobuffer, sectname);
+
+      if (strcmp((FAR const char *)loadinfo->iobuffer, sectname) == 0)
+        {
+          /* We found it... return the index */
+
+          return i;
+        }
+    }
+
+  /* We failed to find a section with this name. */
+
+  return -ENOENT;
+}
diff --git a/nuttx/binfmt/libelf/libelf_symbols.c b/nuttx/binfmt/libelf/libelf_symbols.c
new file mode 100644
index 000000000..2d94b11af
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_symbols.c
@@ -0,0 +1,329 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_symbols.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <elf32.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/binfmt/elf.h>
+#include <nuttx/binfmt/symtab.h>
+
+#include "libelf.h"
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+#ifndef CONFIG_ELF_BUFFERINCR
+#  define CONFIG_ELF_BUFFERINCR 32
+#endif
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_symname
+ *
+ * Description:
+ *   Get the symbol name in loadinfo->iobuffer[].
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+static int elf_symname(FAR struct elf_loadinfo_s *loadinfo,
+                       FAR const Elf32_Sym *sym)
+{
+  FAR uint8_t *buffer;
+  off_t  offset;
+  size_t readlen;
+  size_t bytesread;
+  int ret;
+
+  /* Get the file offset to the string that is the name of the symbol.  The
+   * st_name member holds an offset into the file's symbol string table.
+   */
+
+  if (sym->st_name == 0)
+    {
+      bdbg("Symbol has no name\n");
+      return -ENOENT;
+    }
+
+  offset = loadinfo->shdr[loadinfo->strtabidx].sh_offset + sym->st_name;
+
+  /* Loop until we get the entire symbol name into memory */
+
+  bytesread = 0;
+
+  for (;;)
+    {
+      /* Get the number of bytes to read */
+
+      readlen = loadinfo->buflen - bytesread;
+      if (offset + readlen > loadinfo->filelen)
+        {
+          readlen = loadinfo->filelen - offset;
+          if (readlen <= 0)
+            {
+              bdbg("At end of file\n");
+              return -EINVAL;
+            }
+        }
+
+      /* Read that number of bytes into the array */
+
+      buffer = &loadinfo->iobuffer[bytesread];
+      ret = elf_read(loadinfo, buffer, readlen, offset);
+      if (ret < 0)
+        {
+          bdbg("elf_read failed: %d\n", ret);
+          return ret;
+        }
+
+      bytesread += readlen;
+
+      /* Did we read the NUL terminator? */
+
+      if (memchr(buffer, '\0', readlen) != NULL)
+        {
+          /* Yes, the buffer contains a NUL terminator. */
+
+          return OK;
+        }
+
+      /* No.. then we have to read more */
+
+      ret = elf_reallocbuffer(loadinfo, CONFIG_ELF_BUFFERINCR);
+      if (ret < 0)
+        {
+          bdbg("elf_reallocbuffer failed: %d\n", ret);
+          return ret;
+        }
+    }
+
+  /* We will not get here */
+
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_findsymtab
+ *
+ * Description:
+ *   Find the symbol table section.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_findsymtab(FAR struct elf_loadinfo_s *loadinfo)
+{
+  int i;
+
+  /* Find the symbol table section header and its associated string table */
+
+  for (i = 1; i < loadinfo->ehdr.e_shnum; i++)
+    {
+      if (loadinfo->shdr[i].sh_type == SHT_SYMTAB)
+        {
+          loadinfo->symtabidx = i;
+          loadinfo->strtabidx = loadinfo->shdr[i].sh_link;
+          break;
+        }
+    }
+
+  /* Verify that there is a symbol and string table */
+
+  if (loadinfo->symtabidx == 0)
+    {
+      bdbg("No symbols in ELF file\n");
+      return -EINVAL;
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: elf_readsym
+ *
+ * Description:
+ *   Read the ELFT symbol structure at the specfied index into memory.
+ *
+ * Input Parameters:
+ *   loadinfo - Load state information
+ *   index    - Symbol table index
+ *   sym      - Location to return the table entry
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_readsym(FAR struct elf_loadinfo_s *loadinfo, int index,
+                FAR Elf32_Sym *sym)
+{
+  FAR Elf32_Shdr *symtab = &loadinfo->shdr[loadinfo->symtabidx];
+  off_t offset;
+
+  /* Verify that the symbol table index lies within symbol table */
+
+  if (index < 0 || index > (symtab->sh_size / sizeof(Elf32_Sym)))
+    {
+      bdbg("Bad relocation symbol index: %d\n", index);
+      return -EINVAL;
+    }
+
+  /* Get the file offset to the symbol table entry */
+
+  offset = symtab->sh_offset + sizeof(Elf32_Sym) * index;
+
+  /* And, finally, read the symbol table entry into memory */
+
+  return elf_read(loadinfo, (FAR uint8_t*)sym, sizeof(Elf32_Sym), offset);
+}
+
+/****************************************************************************
+ * Name: elf_symvalue
+ *
+ * Description:
+ *   Get the value of a symbol.  The updated value of the symbol is returned
+ *   in the st_value field of the symbol table entry.
+ *
+ * Input Parameters:
+ *   loadinfo - Load state information
+ *   sym      - Symbol table entry (value might be undefined)
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_symvalue(FAR struct elf_loadinfo_s *loadinfo, FAR Elf32_Sym *sym,
+                 FAR const struct symtab_s *exports, int nexports)
+{
+  FAR const struct symtab_s *symbol;
+  uintptr_t secbase;
+  int ret;
+
+  switch (sym->st_shndx)
+    {
+    case SHN_COMMON:
+      {
+        /* NuttX ELF modules should be compiled with -fno-common. */
+
+        bdbg("SHN_COMMON: Re-compile with -fno-common\n");
+        return -EINVAL;
+      }
+
+    case SHN_ABS:
+      {
+        /* st_value already holds the correct value */
+
+        bvdbg("SHN_ABS: st_value=%08lx\n", (long)sym->st_value);
+        return OK;
+      }
+
+    case SHN_UNDEF:
+      {
+        /* Get the name of the undefined symbol */
+
+        ret = elf_symname(loadinfo, sym);
+        if (ret < 0)
+          {
+            bdbg("SHN_UNDEF: Failed to get symbol name: %d\n", ret);
+            return ret;
+          }
+
+        /* Check if the base code exports a symbol of this name */
+
+#ifdef CONFIG_SYMTAB_ORDEREDBYNAME
+        symbol = symtab_findorderedbyname(exports, (FAR char *)loadinfo->iobuffer, nexports);
+#else
+        symbol = symtab_findbyname(exports, (FAR char *)loadinfo->iobuffer, nexports);
+#endif
+        if (!symbol)
+          {
+            bdbg("SHN_UNDEF: Exported symbol \"%s\" not found\n", loadinfo->iobuffer);
+            return -ENOENT;
+          }
+
+        /* Yes... add the exported symbol value to the ELF symbol table entry */
+
+        bvdbg("SHN_ABS: name=%s %08x+%08x=%08x\n",
+              loadinfo->iobuffer, sym->st_value, symbol->sym_value,
+              sym->st_value + symbol->sym_value);
+
+        sym->st_value += (Elf32_Word)((uintptr_t)symbol->sym_value);
+      }
+      break;
+
+    default:
+      {
+        secbase = loadinfo->shdr[sym->st_shndx].sh_addr;
+
+        bvdbg("Other: %08x+%08x=%08x\n",
+              sym->st_value, secbase, sym->st_value + secbase);
+
+        sym->st_value += secbase;
+      }
+      break;
+    }
+
+  return OK;
+}
diff --git a/nuttx/binfmt/libelf/libelf_uninit.c b/nuttx/binfmt/libelf/libelf_uninit.c
new file mode 100644
index 000000000..3ec6f6c61
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_uninit.c
@@ -0,0 +1,126 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_uninit.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <unistd.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_uninit
+ *
+ * Description:
+ *   Releases any resources committed by elf_init().  This essentially
+ *   undoes the actions of elf_init.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_uninit(struct elf_loadinfo_s *loadinfo)
+{
+  /* Free all working buffers */
+
+  elf_freebuffers(loadinfo);
+
+  /* Close the ELF file */
+
+  if (loadinfo->filfd >= 0)
+    {
+      close(loadinfo->filfd);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: elf_freebuffers
+ *
+ * Description:
+ *  Release all working buffers.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_freebuffers(struct elf_loadinfo_s *loadinfo)
+{
+  /* Release all working allocations  */
+
+  if (loadinfo->shdr)
+    {
+      kfree((FAR void *)loadinfo->shdr);
+      loadinfo->shdr      = NULL;
+    }
+
+  if (loadinfo->iobuffer)
+    {
+      kfree((FAR void *)loadinfo->iobuffer);
+      loadinfo->iobuffer  = NULL;
+      loadinfo->buflen    = 0;
+    }
+
+  return OK;
+}
diff --git a/nuttx/binfmt/libelf/libelf_verify.c b/nuttx/binfmt/libelf/libelf_verify.c
new file mode 100644
index 000000000..c5f185ec3
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_verify.c
@@ -0,0 +1,120 @@
+/****************************************************************************
+ * binfmt/libelf/elf_verify.c
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <nuttx/binfmt/elf.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+static const char g_elfmagic[EI_MAGIC_SIZE] = { 0x7f, 'E', 'L', 'F' };
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_verifyheader
+ *
+ * Description:
+ *   Given the header from a possible ELF executable, verify that it
+ *   is an ELF executable.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ *   -ENOEXEC  : Not an ELF file
+ *   -EINVAL : Not a relocatable ELF file or not supported by the current,
+ *               configured architecture.
+ *
+ ****************************************************************************/
+
+int elf_verifyheader(FAR const Elf32_Ehdr *ehdr)
+{
+  if (!ehdr)
+    {
+      bdbg("NULL ELF header!");
+      return -ENOEXEC;
+    }
+
+  /* Verify that the magic number indicates an ELF file */
+
+  if (memcmp(ehdr->e_ident, g_elfmagic, EI_MAGIC_SIZE) != 0)
+    {
+      bvdbg("Not ELF magic {%02x, %02x, %02x, %02x}\n",
+            ehdr->e_ident[0], ehdr->e_ident[1], ehdr->e_ident[2], ehdr->e_ident[3]);
+      return -ENOEXEC;
+    }
+
+  /* Verify that this is a relocatable file */
+
+  if (ehdr->e_type != ET_REL)
+    {
+      bdbg("Not a relocatable file: e_type=%d\n", ehdr->e_type);
+      return -EINVAL;
+    }
+
+  /* Verify that this file works with the currently configured architecture */
+
+  if (arch_checkarch(ehdr))
+    {
+      bdbg("Not a supported architecture\n");
+      return -ENOEXEC;
+    }
+
+  /* Looks good so far... we still might find some problems later. */
+
+  return OK;
+}
+