Add framework to support loadable ELF modules (not much logic in place yet)

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5250 42af7a65-404d-4744-a932-0658087f49c3

18 files changed, 1441 insertions, 62 deletions

diff --git a/nuttx/binfmt/Kconfig b/nuttx/binfmt/Kconfig
index ae2bf3130..3519536fb 100644
--- a/nuttx/binfmt/Kconfig
+++ b/nuttx/binfmt/Kconfig
@@ -2,3 +2,37 @@
 # For a description of the syntax of this configuration file,
 # see misc/tools/kconfig-language.txt.
 #
+
+config BINFMT_DISABLE
+	bool "Disble BINFMT support"
+	default n
+	---help---
+		By default, support for loadable binary formats is built.  This logic
+		may be suppressed be defining this setting.
+
+if !BINFMT_DISABLE
+
+config NXFLAT
+	bool "Enable the NXFLAT Binary Format"
+	default n
+	---help---
+		Enable support for the NXFLAT binary format.  Default: n
+
+if NXFLAT
+include binfmt/libnxflat/Kconfig
+endif
+
+config ELF
+	bool "Enable the ELF Binary Format"
+	default n
+	---help---
+		Enable support for the ELF binary format.  Default: n
+
+if ELF
+include binfmt/libelf/Kconfig
+endif
+endif
+
+config SYMTAB_ORDEREDBYNAME
+	bool "Symbol Tables Ordered by Name"
+	default n
diff --git a/nuttx/binfmt/Makefile b/nuttx/binfmt/Makefile
index b3a9269b3..1b98e3ede 100644
--- a/nuttx/binfmt/Makefile
+++ b/nuttx/binfmt/Makefile
@@ -1,7 +1,7 @@
 ############################################################################
 # nxflat/Makefile
 #
-#   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2007-2009, 2012 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -36,55 +36,54 @@
 -include $(TOPDIR)/Make.defs
 
 ifeq ($(WINTOOL),y)
-INCDIROPT	= -w
+INCDIROPT		= -w
 endif
-CFLAGS		+= ${shell $(TOPDIR)/tools/incdir.sh $(INCDIROPT) "$(CC)" $(TOPDIR)/sched}
+CFLAGS			+= ${shell $(TOPDIR)/tools/incdir.sh $(INCDIROPT) "$(CC)" $(TOPDIR)/sched}
 
-ifeq ($(CONFIG_NXFLAT),y)
-include libnxflat/Make.defs
-LIBNXFLAT_CSRCS	+= nxflat.c 
-endif
+# Basic BINFMT source files 
 
 BINFMT_ASRCS	=
 BINFMT_CSRCS	= binfmt_globals.c binfmt_register.c binfmt_unregister.c \
-		  binfmt_loadmodule.c binfmt_unloadmodule.c binfmt_execmodule.c \
-		  binfmt_exec.c binfmt_dumpmodule.c
+				  binfmt_loadmodule.c binfmt_unloadmodule.c binfmt_execmodule.c \
+				  binfmt_exec.c binfmt_dumpmodule.c
 
-SYMTAB_ASRCS	=
-SYMTAB_CSRCS	= symtab_findbyname.c symtab_findbyvalue.c \
-		  symtab_findorderedbyname.c symtab_findorderedbyvalue.c
+# Symbol table source files
 
-SUBDIRS		= libnxflat
+BINFMT_CSRCS	+= symtab_findbyname.c symtab_findbyvalue.c \
+				   symtab_findorderedbyname.c symtab_findorderedbyvalue.c
 
-ASRCS		= $(BINFMT_ASRCS) $(SYMTAB_ASRCS) $(LIBNXFLAT_ASRCS)
-AOBJS		= $(ASRCS:.S=$(OBJEXT))
+# Add configured binary modules
 
-CSRCS		= $(BINFMT_CSRCS) $(SYMTAB_CSRCS) $(LIBNXFLAT_CSRCS)
-COBJS		= $(CSRCS:.c=$(OBJEXT))
+VPATH			= 
+SUBDIRS			=
+
+include libnxflat/Make.defs
+include libelf/Make.defs
 
-SRCS		= $(ASRCS) $(CSRCS)
-OBJS		= $(AOBJS) $(COBJS)
+BINFMT_AOBJS	= $(BINFMT_ASRCS:.S=$(OBJEXT))
+BINFMT_COBJS	= $(BINFMT_CSRCS:.c=$(OBJEXT))
 
-BIN		= libbinfmt$(LIBEXT)
+BINFMT_SRCS		= $(BINFMT_ASRCS) $(BINFMT_CSRCS)
+BINFMT_OBJS		= $(BINFMT_AOBJS) $(BINFMT_COBJS)
 
-VPATH		= libnxflat
+BIN				= libbinfmt$(LIBEXT)
 
-all:	$(BIN)
+all: $(BIN)
 
-$(AOBJS): %$(OBJEXT): %.S
+$(BINFMT_AOBJS): %$(OBJEXT): %.S
 	$(call ASSEMBLE, $<, $@)
 
-$(COBJS): %$(OBJEXT): %.c
+$(BINFMT_COBJS): %$(OBJEXT): %.c
 	$(call COMPILE, $<, $@)
 
-$(BIN): $(OBJS)
-	@( for obj in $(OBJS) ; do \
+$(BIN): $(BINFMT_OBJS)
+	@( for obj in $(BINFMT_OBJS) ; do \
 		$(call ARCHIVE, $@, $${obj}); \
 	done ; )
 
-.depend: Makefile $(SRCS)
+.depend: Makefile $(BINFMT_SRCS)
 	@$(MKDEP) --dep-path . --dep-path libnxflat \
-		$(CC) -- $(CFLAGS) -- $(SRCS) >Make.dep
+		$(CC) -- $(CFLAGS) -- $(BINFMT_SRCS) >Make.dep
 	@touch $@
 
 depend: .depend
diff --git a/nuttx/binfmt/elf.c b/nuttx/binfmt/elf.c
new file mode 100644
index 000000000..74a35174f
--- /dev/null
+++ b/nuttx/binfmt/elf.c
@@ -0,0 +1,259 @@
+/****************************************************************************
+ * binfmt/elf.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/types.h>
+#include <stdint.h>
+#include <string.h>
+#include <elf.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <arpa/inet.h>
+#include <nuttx/binfmt.h>
+#include <nuttx/elf.h>
+
+#ifdef CONFIG_ELF
+
+/****************************************************************************
+ * 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
+
+#ifndef MIN
+#  define MIN(a,b) (a < b ? a : b)
+#endif
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int elf_loadbinary(FAR struct binary_s *binp);
+#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_BINFMT)
+static void elf_dumploadinfo(FAR struct elf_loadinfo_s *loadinfo);
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct binfmt_s g_elfbinfmt =
+{
+  NULL,             /* next */
+  elf_loadbinary,   /* load */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_dumploadinfo
+ ****************************************************************************/
+
+#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_BINFMT)
+static void elf_dumploadinfo(FAR struct elf_loadinfo_s *loadinfo)
+{
+  unsigned long dsize = loadinfo->datasize + loadinfo->bsssize;
+
+  bdbg("LOAD_INFO:\n");
+  bdbg("  ISPACE:\n");
+  bdbg("    ispace:       %08lx\n", loadinfo->ispace);
+  bdbg("    entryoffs:    %08lx\n", loadinfo->entryoffs);
+  bdbg("    isize:        %08lx\n", loadinfo->isize);
+
+  bdbg("  DSPACE:\n");
+  bdbg("    dspace:       %08lx\n", loadinfo->dspace);
+  if (loadinfo->dspace != NULL)
+    {
+      bdbg("      crefs:      %d\n",    loadinfo->dspace->crefs);
+      bdbg("      region:     %08lx\n", loadinfo->dspace->region);
+    }
+  bdbg("    datasize:     %08lx\n", loadinfo->datasize);
+  bdbg("    bsssize:      %08lx\n", loadinfo->bsssize);
+  bdbg("      (pad):      %08lx\n", loadinfo->dsize - dsize);
+  bdbg("    stacksize:    %08lx\n", loadinfo->stacksize);
+  bdbg("    dsize:        %08lx\n", loadinfo->dsize);
+
+  bdbg("  RELOCS:\n");
+  bdbg("    relocstart:   %08lx\n", loadinfo->relocstart);
+  bdbg("    reloccount:   %d\n",    loadinfo->reloccount);
+
+  bdbg("  HANDLES:\n");
+  bdbg("    filfd:        %d\n",    loadinfo->filfd);
+}
+#else
+# define elf_dumploadinfo(i)
+#endif
+
+/****************************************************************************
+ * Name: elf_loadbinary
+ *
+ * Description:
+ *   Verify that the file is an ELF binary and, if so, load the ELF
+ *   binary into memory
+ *
+ ****************************************************************************/
+
+static int elf_loadbinary(struct binary_s *binp)
+{
+  struct elf_loadinfo_s loadinfo;  /* Contains globals for libelf */
+  int                      ret;
+
+  bvdbg("Loading file: %s\n", binp->filename);
+
+  /* Initialize the xflat library to load the program binary. */
+
+  ret = elf_init(binp->filename, &loadinfo);
+  elf_dumploadinfo(&loadinfo);
+  if (ret != 0)
+    {
+      bdbg("Failed to initialize for load of NXFLT program: %d\n", ret);
+      goto errout;
+    }
+
+  /* Load the program binary */
+
+  ret = elf_load(&loadinfo);
+  elf_dumploadinfo(&loadinfo);
+  if (ret != 0)
+    {
+      bdbg("Failed to load NXFLT program binary: %d\n", ret);
+      goto errout_with_init;
+    }
+
+  /* Bind the program to the exported symbol table */
+
+  ret = elf_bind(&loadinfo, binp->exports, binp->nexports);
+  if (ret != 0)
+    {
+      bdbg("Failed to bind symbols program binary: %d\n", ret);
+      goto errout_with_load;
+    }
+
+  /* Return the load information */
+
+  binp->entrypt   = (main_t)(loadinfo.ispace + loadinfo.entryoffs);
+  binp->ispace    = (void*)loadinfo.ispace;
+  binp->dspace    = (void*)loadinfo.dspace;
+  binp->isize     = loadinfo.isize;
+  binp->stacksize = loadinfo.stacksize;
+
+  elf_dumpbuffer("Entry code", (FAR const uint8_t*)binp->entrypt,
+                    MIN(binp->isize - loadinfo.entryoffs,512));
+
+  elf_uninit(&loadinfo);
+  return OK;
+
+errout_with_load:
+  elf_unload(&loadinfo);
+errout_with_init:
+  elf_uninit(&loadinfo);
+errout:
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_initialize
+ *
+ * Description:
+ *   ELF support is built unconditionally.  However, it order to
+ *   use this binary format, this function must be called during system
+ *   format in order to register the ELF binary format.
+ *
+ * Returned Value:
+ *   This is a NuttX internal function so it follows the convention that
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_initialize(void)
+{
+  int ret;
+
+  /* Register ourselves as a binfmt loader */
+
+  bvdbg("Registering ELF\n");
+
+  ret = register_binfmt(&g_elfbinfmt);
+  if (ret != 0)
+    {
+      bdbg("Failed to register binfmt: %d\n", ret);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: elf_uninitialize
+ *
+ * Description:
+ *   Unregister the ELF binary loader
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void elf_uninitialize(void)
+{
+  unregister_binfmt(&g_elfbinfmt);
+}
+
+#endif /* CONFIG_ELF */
+
diff --git a/nuttx/binfmt/libelf/Kconfig b/nuttx/binfmt/libelf/Kconfig
new file mode 100644
index 000000000..c47bc9f9e
--- /dev/null
+++ b/nuttx/binfmt/libelf/Kconfig
@@ -0,0 +1,9 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+config ELF_DUMPBUFFER
+	bool "Dump ELF buffers"
+	default n
+	depends on DEBUG && DEBUG_VERBOSE
diff --git a/nuttx/binfmt/libelf/Make.defs b/nuttx/binfmt/libelf/Make.defs
new file mode 100644
index 000000000..629961863
--- /dev/null
+++ b/nuttx/binfmt/libelf/Make.defs
@@ -0,0 +1,53 @@
+############################################################################
+# binfmt/libelf/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_ELF),y)
+
+# ELF application interfaces
+
+BINFMT_CSRCS += elf.c
+
+# ELF library
+
+BINFMT_CSRCS = libelf_init.c libelf_uninit.c libelf_load.c \
+			   libelf_unload.c libelf_verify.c libelf_read.c \
+			   libelf_bind.c
+
+# Hook the libelf subdirectory into the build
+
+VPATH += libelf
+SUBDIRS += libelf
+
+endif
diff --git a/nuttx/binfmt/libelf/gnu-elf.ld b/nuttx/binfmt/libelf/gnu-elf.ld
new file mode 100644
index 000000000..703f36981
--- /dev/null
+++ b/nuttx/binfmt/libelf/gnu-elf.ld
@@ -0,0 +1,187 @@
+/****************************************************************************
+ * examples/elf/gnu-elf-gotoff.ld
+ *
+ *   Copyright (C) 2009, 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.
+ *
+ ****************************************************************************/
+
+MEMORY 
+{
+  ISPACE : ORIGIN = 0x0, LENGTH = 2097152
+  DSPACE : ORIGIN = 0x0, LENGTH = 2097152
+}
+
+/****************************************************************************
+ * The XFLAT program image is divided into two segments:
+ *
+ * (1) ISpace (Instruction Space).  This is the segment that contains
+ *     code (.text).  Everything in the segment should be fetch-able
+ *     machine PC instructions (jump, branch, call, etc.).
+ * (2) DSpace (Data Space).  This is the segment that contains both
+ *     read-write data (.data, .bss) as well as read-only data (.rodata).
+ *     Everything in this segment should be access-able with machine
+ *     PIC load and store instructions.
+ *
+ * Older versions of GCC (at least up to GCC 4.3.3), use GOT-relative
+ * addressing to access RO data. In that case, read-only data (.rodata) must
+ * reside in D-Space and this linker script should be used.
+ *
+ * Newer versions of GCC (at least as of GCC 4.6.3), use PC-relative
+ * addressing to access RO data. In that case, read-only data (.rodata) must
+ * reside in I-Space and this linker script should NOT be used with those
+ * newer tools.
+ *
+ ****************************************************************************/
+
+SECTIONS
+{
+  .text 0x00000000 :
+    {
+      /* ISpace is located at address 0.  Every (unrelocated) ISpace
+       * address is an offset from the begining of this segment.
+       */
+
+      text_start = . ;
+
+      *(.text)
+      *(.text.*)
+      *(.gnu.warning)
+      *(.stub)
+      *(.glue_7)
+      *(.glue_7t)
+      *(.jcr)
+
+      /* C++ support:  The .init and .fini sections contain XFLAT-
+       * specific logic to manage static constructors and destructors.
+       */
+
+      *(.gnu.linkonce.t.*)
+      *(.init)
+      *(.fini)
+
+      /* This is special code area at the end of the normal
+         text section.  It contains a small lookup table at
+         the start followed by the code pointed to by entries
+         in the lookup table.  */
+
+      . = ALIGN (4) ;
+      PROVIDE(__ctbp = .);
+      *(.call_table_data)
+      *(.call_table_text)
+
+      _etext = . ;
+
+    } > ISPACE
+
+    /* DSpace is also located at address 0.  Every (unrelocated) DSpace
+     * address is an offset from the begining of this segment.
+     */
+
+  .data 0x00000000 :
+    {
+      /* In this model, .rodata is access using PC-relative addressing
+       * and, hence, must also reside in the .text section.
+       */
+
+      __data_start = . ;
+      *(.rodata)
+      *(.rodata1)
+      *(.rodata.*)
+      *(.gnu.linkonce.r*)
+
+      *(.data)
+      *(.data1)
+      *(.data.*)
+      *(.gnu.linkonce.d*)
+      *(.data1)
+      *(.eh_frame)
+      *(.gcc_except_table)
+
+      *(.gnu.linkonce.s.*)
+      *(__libc_atexit)
+      *(__libc_subinit)
+      *(__libc_subfreeres)
+      *(.note.ABI-tag)
+
+      /* 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.
+       */
+
+      *(.gnu.linkonce.d.*)
+
+      _ctors_start = . ;
+      *(.ctors)
+      _ctors_end = . ;
+      _dtors_start = . ;
+      *(.dtors)
+      _dtors_end = . ;
+
+      _edata = . ;
+      edata = ALIGN( 0x10 ) ;
+    } > DSPACE
+
+  .bss :
+    {
+      __bss_start = _edata ;
+      *(.dynsbss)
+      *(.sbss)
+      *(.sbss.*)
+      *(.scommon)
+      *(.dynbss)
+      *(.bss)
+      *(.bss.*)
+      *(.bss*)
+      *(.gnu.linkonce.b*)
+      *(COMMON)
+      end = ALIGN( 0x10 ) ;
+      _end = ALIGN( 0x10 ) ;
+    } > DSPACE
+
+    .got 0 : { *(.got.plt) *(.got) }
+    .junk 0 : { *(.rel*) *(.rela*) }
+    /* 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_bind.c b/nuttx/binfmt/libelf/libelf_bind.c
new file mode 100644
index 000000000..44532ab88
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_bind.c
@@ -0,0 +1,106 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_bind.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 <stdint.h>
+#include <string.h>
+#include <elf.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <arpa/inet.h>
+#include <nuttx/elf.h>
+#include <nuttx/symtab.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 Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_bind
+ *
+ * Description:
+ *   Bind the imported symbol names in the loaded module described by
+ *   'loadinfo' using the exported symbol values provided by 'symtab'.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_bind(FAR struct elf_loadinfo_s *loadinfo,
+             FAR const struct symtab_s *exports, int nexports)
+{
+#warning "Missing logic"
+  return -ENOSYS;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_init.c b/nuttx/binfmt/libelf/libelf_init.c
new file mode 100644
index 000000000..d72e96b62
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_init.c
@@ -0,0 +1,189 @@
+/****************************************************************************
+ * 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 <elf.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <arpa/inet.h>
+#include <nuttx/elf.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
+ ****************************************************************************/
+
+/****************************************************************************
+ * 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)
+{
+  uint32_t datastart;
+  uint32_t dataend;
+  uint32_t bssstart;
+  uint32_t bssend;
+  int      ret;
+
+  bvdbg("filename: %s loadinfo: %p\n", filename, loadinfo);
+
+  /* Clear the load info structure */
+
+  memset(loadinfo, 0, sizeof(struct elf_loadinfo_s));
+
+  /* Open the binary file */
+
+  loadinfo->filfd = open(filename, O_RDONLY);
+  if (loadinfo->filfd < 0)
+    {
+      bdbg("Failed to open ELF binary %s: %d\n", filename, ret);
+      return -errno;      
+    }
+
+  /* Read the ELF header from offset 0 */
+
+  ret = elf_read(loadinfo, (char*)&loadinfo->header,
+                    sizeof(struct elf_hdr_s), 0);
+  if (ret < 0)
+    {
+      bdbg("Failed to read ELF header: %d\n", ret);
+      return ret;
+    }
+
+  elf_dumpbuffer("ELF header", (FAR const uint8_t*)&loadinfo->header,
+                    sizeof(struct elf_hdr_s));
+
+  /* Verify the ELF header */
+
+  if (elf_verifyheader(&loadinfo->header) != 0)
+    {
+      /* This is not an error because we will be called to attempt loading
+       * EVERY binary.  Returning -ENOEXEC simply informs the system that
+       * the file is not an ELF file.  Besides, if there is something worth
+       * complaining about, nelf_verifyheader() has already
+       * done so.
+       */
+
+      bdbg("Bad ELF header\n");
+      return -ENOEXEC;
+    }
+
+  /* Save all of the input values in the loadinfo structure 
+   * and extract some additional information from the xflat
+   * header.  Note that the information in the xflat header is in
+   * network order.
+   */
+
+  datastart             = ntohl(loadinfo->header.h_datastart);
+  dataend               = ntohl(loadinfo->header.h_dataend);
+  bssstart              = dataend;
+  bssend                = ntohl(loadinfo->header.h_bssend);
+
+  /* And put this information into the loadinfo structure as well.
+   *
+   * Note that:
+   *
+   *   isize       = the address range from 0 up to datastart.
+   *   datasize   = the address range from datastart up to dataend
+   *   bsssize    = the address range from dataend up to bssend.
+   */
+
+  loadinfo->entryoffs   = ntohl(loadinfo->header.h_entry);
+  loadinfo->isize       = datastart;
+
+  loadinfo->datasize    = dataend - datastart;
+  loadinfo->bsssize     = bssend - dataend;
+  loadinfo->stacksize   = ntohl(loadinfo->header.h_stacksize);
+
+  /* This is the initial dspace size.  We'll re-calculate this later
+   * after the memory has been allocated.
+   */
+
+  loadinfo->dsize       = bssend - datastart;
+
+  /* Get the offset to the start of the relocations (we'll relocate
+   * this later).
+   */
+
+  loadinfo->relocstart  = ntohl(loadinfo->header.h_relocstart);
+  loadinfo->reloccount  = ntohs(loadinfo->header.h_reloccount);
+
+  return 0;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_load.c b/nuttx/binfmt/libelf/libelf_load.c
new file mode 100644
index 000000000..94d200b56
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_load.c
@@ -0,0 +1,91 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_load.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/types.h>
+#include <sys/mman.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <elf.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <arpa/inet.h>
+#include <nuttx/elf.h>
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+#ifndef MAX
+#define MAX(x,y) ((x) > (y) ? (x) : (y))
+#endif
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_load
+ *
+ * Description:
+ *   Loads the binary into memory, allocating memory, performing relocations
+ *   and inializing the data and bss segments.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_load(FAR struct elf_loadinfo_s *loadinfo)
+{
+# warning "Missing logic"
+  return -ENOSYS;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_read.c b/nuttx/binfmt/libelf/libelf_read.c
new file mode 100644
index 000000000..5f00a531e
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_read.c
@@ -0,0 +1,165 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_read.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/types.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <elf.h>
+#include <debug.h>
+#include <errno.h>
+
+#include <arpa/inet.h>
+#include <nuttx/elf.h>
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+#undef ELF_DUMP_READDATA       /* Define to dump all file data read */
+#define DUMPER lib_rawprintf   /* If ELF_DUMP_READDATA is defined, this
+                                * is the API used to dump data */
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_dumpreaddata
+ ****************************************************************************/
+
+#if defined(ELF_DUMP_READDATA)
+static inline void elf_dumpreaddata(char *buffer, int buflen)
+{
+  uint32_t *buf32 = (uint32_t*)buffer;
+  int i;
+  int j;
+
+  for (i = 0; i < buflen; i += 32)
+    {
+      DUMPER("%04x:", i);
+      for (j = 0; j < 32; j += sizeof(uint32_t))
+        {
+          DUMPER("  %08x", *buf32++);
+        }
+      DUMPER("\n");
+    }
+}
+#else
+#  define elf_dumpreaddata(b,n)
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_read
+ *
+ * Description:
+ *   Read 'readsize' bytes from the object file at 'offset'
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_read(struct elf_loadinfo_s *loadinfo, char *buffer, int readsize, int offset)
+{
+  ssize_t nbytes;      /* Number of bytes read */
+  off_t   rpos;        /* Position returned by lseek */
+  char   *bufptr;      /* Next buffer location to read into */
+  int     bytesleft;   /* Number of bytes of .data left to read */
+  int     bytesread;   /* Total number of bytes read */
+
+  bvdbg("Read %d bytes from offset %d\n", readsize, offset);
+
+  /* Seek to the position in the object file where the initialized
+   * data is saved.
+   */
+
+  bytesread = 0;
+  bufptr    = buffer;
+  bytesleft = readsize;
+  do
+    {
+      rpos = lseek(loadinfo->filfd, offset, SEEK_SET);
+      if (rpos != offset)
+        {
+          bdbg("Failed to seek to position %d: %d\n", offset, errno);
+          return -errno;
+        }
+
+      /* Read the file data at offset into the user buffer */
+
+       nbytes = read(loadinfo->filfd, bufptr, bytesleft);
+       if (nbytes < 0)
+         {
+           if (errno != EINTR)
+             {
+               bdbg("Read of .data failed: %d\n", errno);
+               return -errno;
+             }
+         }
+       else if (nbytes == 0)
+         {
+           bdbg("Unexpected end of file\n");
+           return -ENODATA;
+         }
+       else
+         {
+           bytesread += nbytes;
+           bytesleft -= nbytes;
+           bufptr    += nbytes;
+           offset    += nbytes;
+         }
+    }
+  while (bytesread < readsize);
+
+  elf_dumpreaddata(buffer, readsize);
+  return OK;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_uninit.c b/nuttx/binfmt/libelf/libelf_uninit.c
new file mode 100644
index 000000000..cd7ae7282
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_uninit.c
@@ -0,0 +1,85 @@
+/****************************************************************************
+ * 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/elf.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)
+{
+  if (loadinfo->filfd >= 0)
+    {
+      close(loadinfo->filfd);
+    }
+
+  return OK;
+}
+
diff --git a/nuttx/binfmt/libelf/libelf_unload.c b/nuttx/binfmt/libelf/libelf_unload.c
new file mode 100644
index 000000000..9e930e295
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_unload.c
@@ -0,0 +1,97 @@
+/****************************************************************************
+ * binfmt/libelf/libelf_unload.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/mman.h>
+#include <stdlib.h>
+#include <debug.h>
+
+#include <nuttx/elf.h>
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_unload
+ *
+ * Description:
+ *   This function unloads the object from memory. This essentially
+ *   undoes the actions of elf_load.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_unload(struct elf_loadinfo_s *loadinfo)
+{
+  /* Reset the contents of the info structure. */
+
+  /* Release the memory segments */
+
+  if (loadinfo->ispace)
+    {
+      kfree((void*)loadinfo->ispace, loadinfo->isize);
+      loadinfo->ispace = 0;
+    }
+
+  if (loadinfo->dspace)
+    {
+      kfree((void*)loadinfo->dspace);
+      loadinfo->dspace = 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..9e265573a
--- /dev/null
+++ b/nuttx/binfmt/libelf/libelf_verify.c
@@ -0,0 +1,88 @@
+/****************************************************************************
+ * 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 <arpa/inet.h>
+#include <nuttx/elf.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * 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.
+ *
+ ****************************************************************************/
+
+int elf_verifyheader(const struct elf_hdr_s *header)
+{
+  if (!header)
+    {
+      bdbg("NULL ELF header!");
+      return -ENOEXEC;
+    }
+
+#warning "Missing Logic"
+  return -ENOSYS;
+}
+
diff --git a/nuttx/binfmt/libnxflat/Kconfig b/nuttx/binfmt/libnxflat/Kconfig
index ae2bf3130..fdb270cfb 100644
--- a/nuttx/binfmt/libnxflat/Kconfig
+++ b/nuttx/binfmt/libnxflat/Kconfig
@@ -2,3 +2,8 @@
 # For a description of the syntax of this configuration file,
 # see misc/tools/kconfig-language.txt.
 #
+
+config NXFLAT_DUMPBUFFER
+	bool "Dump NXFLAT buffers"
+	default n
+	depends on DEBUG && DEBUG_VERBOSE
diff --git a/nuttx/binfmt/libnxflat/Make.defs b/nuttx/binfmt/libnxflat/Make.defs
index f979741e5..59c3ce334 100644
--- a/nuttx/binfmt/libnxflat/Make.defs
+++ b/nuttx/binfmt/libnxflat/Make.defs
@@ -1,5 +1,5 @@
 ############################################################################
-# nxflat/lib/Make.defs
+# binfmt/libnxflat/Make.defs
 #
 #   Copyright (C) 2009 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
@@ -33,7 +33,21 @@
 #
 ############################################################################
 
-LIBNXFLAT_ASRCS =
-LIBNXFLAT_CSRCS = libnxflat_init.c libnxflat_uninit.c libnxflat_load.c \
-		  libnxflat_unload.c libnxflat_verify.c libnxflat_read.c \
-		  libnxflat_bind.c
+ifeq ($(CONFIG_NXFLAT),y)
+
+# NXFLAT application interfaces
+
+BINFMT_CSRCS += nxflat.c
+
+# NXFLAT library
+
+BINFMT_CSRCS = libnxflat_init.c libnxflat_uninit.c libnxflat_load.c \
+			   libnxflat_unload.c libnxflat_verify.c libnxflat_read.c \
+			   libnxflat_bind.c
+
+# Hook the libnxflat subdirectory into the build
+
+VPATH += libnxflat
+SUBDIRS += libnxflat
+
+endif
diff --git a/nuttx/binfmt/libnxflat/libnxflat_bind.c b/nuttx/binfmt/libnxflat/libnxflat_bind.c
index ca348178d..c18a16cd8 100644
--- a/nuttx/binfmt/libnxflat/libnxflat_bind.c
+++ b/nuttx/binfmt/libnxflat/libnxflat_bind.c
@@ -263,7 +263,6 @@ static inline int nxflat_gotrelocs(FAR struct nxflat_loadinfo_s *loadinfo)
       result = OK;
       switch (NXFLAT_RELOC_TYPE(reloc.r_info))
         {
-
         /* NXFLAT_RELOC_TYPE_REL32I  Meaning: Object file contains a 32-bit offset
          *                                    into I-Space at the offset.
          *                           Fixup:   Add mapped I-Space address to the offset.
@@ -329,6 +328,7 @@ static inline int nxflat_gotrelocs(FAR struct nxflat_loadinfo_s *loadinfo)
       nxflat_dumpbuffer("GOT", (FAR const uint8_t*)relocs, nrelocs * sizeof(struct nxflat_reloc_s));
     }
 #endif
+
   return ret;
 }
 
@@ -388,7 +388,7 @@ static inline int nxflat_bindimports(FAR struct nxflat_loadinfo_s *loadinfo,
                   offset < loadinfo->isize + loadinfo->dsize);
 
       imports = (struct nxflat_import_s*)
-	(offset - loadinfo->isize + loadinfo->dspace->region);
+        (offset - loadinfo->isize + loadinfo->dspace->region);
 
       /* Now, traverse the list of imported symbols and attempt to bind
        * each symbol to the value exported by from the exported symbol
@@ -396,41 +396,41 @@ static inline int nxflat_bindimports(FAR struct nxflat_loadinfo_s *loadinfo,
        */
 
       for (i = 0; i < nimports; i++)
-	{
-	  bvdbg("Import[%d] (%08p) offset: %08x func: %08x\n",
-	        i, &imports[i], imports[i].i_funcname, imports[i].i_funcaddress);
+        {
+          bvdbg("Import[%d] (%08p) offset: %08x func: %08x\n",
+                i, &imports[i], imports[i].i_funcname, imports[i].i_funcaddress);
 
-	  /* Get a pointer to the imported symbol name.  The name itself
-	   * lies in the TEXT segment.  But the reference to the name
-	   * lies in DATA segment.  Therefore, the name reference should
-	   * have been relocated when the module was loaded.
-	   */
+          /* Get a pointer to the imported symbol name.  The name itself
+           * lies in the TEXT segment.  But the reference to the name
+           * lies in DATA segment.  Therefore, the name reference should
+           * have been relocated when the module was loaded.
+           */
 
           offset = imports[i].i_funcname;
           DEBUGASSERT(offset < loadinfo->isize);
 
-	  symname = (char*)(offset + loadinfo->ispace + sizeof(struct nxflat_hdr_s));
+          symname = (char*)(offset + loadinfo->ispace + sizeof(struct nxflat_hdr_s));
 
-	  /* Find the exported symbol value for this this symbol name. */
+          /* Find the exported symbol value for this this symbol name. */
 
 #ifdef CONFIG_SYMTAB_ORDEREDBYNAME
           symbol = symtab_findorderedbyname(exports, symname, nexports);
 #else
           symbol = symtab_findbyname(exports, symname, nexports);
 #endif
-	  if (!symbol)
-	    {
-	      bdbg("Exported symbol \"%s\" not found\n", symname);
+          if (!symbol)
+            {
+              bdbg("Exported symbol \"%s\" not found\n", symname);
               return -ENOENT;
-	    }
+            }
 
-	  /* And put this into the module's import structure. */
+          /* And put this into the module's import structure. */
 
-	  imports[i].i_funcaddress =  (uint32_t)symbol->sym_value;
+          imports[i].i_funcaddress =  (uint32_t)symbol->sym_value;
 
-	  bvdbg("Bound import[%d] (%08p) to export '%s' (%08x)\n",
-	        i, &imports[i], symname, imports[i].i_funcaddress);
-	}
+          bvdbg("Bound import[%d] (%08p) to export '%s' (%08x)\n",
+                i, &imports[i], symname, imports[i].i_funcaddress);
+        }
     }
 
   /* Dump the relocation import table */
@@ -441,6 +441,7 @@ static inline int nxflat_bindimports(FAR struct nxflat_loadinfo_s *loadinfo,
       nxflat_dumpbuffer("Imports", (FAR const uint8_t*)imports, nimports * sizeof(struct nxflat_import_s));
     }
 #endif
+
   return OK;
 }
 
@@ -484,9 +485,10 @@ int nxflat_bind(FAR struct nxflat_loadinfo_s *loadinfo,
            */
 
           memset((void*)(loadinfo->dspace->region + loadinfo->datasize),
-	                  0, loadinfo->bsssize);
+                      0, loadinfo->bsssize);
         }
     }
+
   return ret;
 }
 
diff --git a/nuttx/binfmt/libnxflat/libnxflat_uninit.c b/nuttx/binfmt/libnxflat/libnxflat_uninit.c
index 5d06296c7..c507fdc14 100644
--- a/nuttx/binfmt/libnxflat/libnxflat_uninit.c
+++ b/nuttx/binfmt/libnxflat/libnxflat_uninit.c
@@ -57,10 +57,6 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: nxflat_swap32
- ****************************************************************************/
-
-/****************************************************************************
  * Public Functions
  ****************************************************************************/
 
diff --git a/nuttx/binfmt/libnxflat/libnxflat_verify.c b/nuttx/binfmt/libnxflat/libnxflat_verify.c
index f799aca4f..da25d21c7 100644
--- a/nuttx/binfmt/libnxflat/libnxflat_verify.c
+++ b/nuttx/binfmt/libnxflat/libnxflat_verify.c
@@ -91,10 +91,10 @@ int nxflat_verifyheader(const struct nxflat_hdr_s *header)
   if (strncmp(header->h_magic, NXFLAT_MAGIC, 4) != 0)
     {
       bdbg("Unrecognized magic=\"%c%c%c%c\"\n",
-	  header->h_magic[0], header->h_magic[1],
-	  header->h_magic[2], header->h_magic[3]);
+      header->h_magic[0], header->h_magic[1],
+      header->h_magic[2], header->h_magic[3]);
       return -ENOEXEC;
     }
+
   return OK;
 }
-