Add NXFLAT dynamic binding logic

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1919 42af7a65-404d-4744-a932-0658087f49c3

4 files changed, 188 insertions, 5 deletions

diff --git a/nuttx/binfmt/binfmt_loadmodule.c b/nuttx/binfmt/binfmt_loadmodule.c
index 1034ad16f..c251f0af7 100644
--- a/nuttx/binfmt/binfmt_loadmodule.c
+++ b/nuttx/binfmt/binfmt_loadmodule.c
@@ -74,7 +74,8 @@
  * Name: load_module
  *
  * Description:
- *   Load a module into memory and prep it for execution.
+ *   Load a module into memory, bind it to an exported symbol take, and
+ *   prep the module for execution.
  *
  * Returned Value:
  *   This is an end-user function, so it follows the normal convention:
@@ -83,7 +84,7 @@
  *
  ****************************************************************************/
 
-int load_module(const char *filename, FAR struct binary_s *bin)
+int load_module(FAR struct binary_s *bin)
 {
   FAR struct binfmt_s *binfmt;
   int ret;
@@ -96,7 +97,7 @@ int load_module(const char *filename, FAR struct binary_s *bin)
   else
 #endif
     {
-      bdbg("Loading %s\n", filename);
+      bdbg("Loading %s\n", bin->filename);
 
       /* Disabling pre-emption should be sufficient protection while
        * accessing the list of registered binary format handlers.
@@ -116,7 +117,6 @@ int load_module(const char *filename, FAR struct binary_s *bin)
           ret = binfmt->load(bin);
           if (ret == OK)
             {
-
               /* Successfully loaded -- break out with ret == 0 */
 
               dump_module(bin);
diff --git a/nuttx/binfmt/libnxflat/Make.defs b/nuttx/binfmt/libnxflat/Make.defs
index 21d00f7f1..9e9593651 100644
--- a/nuttx/binfmt/libnxflat/Make.defs
+++ b/nuttx/binfmt/libnxflat/Make.defs
@@ -35,4 +35,5 @@
 
 LIBNXFLAT_ASRCS =
 LIBNXFLAT_CSRCS = libnxflat_init.c libnxflat_uninit.c libnxflat_load.c \
-		  libnxflat_unload.c libnxflat_verify.c libnxflat_read.c
+		  libnxflat_unload.c libnxflat_verify.c libnxflat_read.c \
+		  libnxflat_bind.c
diff --git a/nuttx/binfmt/libnxflat/libnxflat_bind.c b/nuttx/binfmt/libnxflat/libnxflat_bind.c
new file mode 100644
index 000000000..887fcfe58
--- /dev/null
+++ b/nuttx/binfmt/libnxflat/libnxflat_bind.c
@@ -0,0 +1,172 @@
+/****************************************************************************
+ * binfmt/libnxflat/libnxflat_bind.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <nxflat.h>
+#include <errno.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <arpa/inet.h>
+#include <nuttx/nxflat.h>
+#include <nuttx/symtab.h>
+
+/****************************************************************************
+ * Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/***********************************************************************
+ * Name: nxflat_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 nxflat_bind(FAR struct nxflat_loadinfo_s *loadinfo,
+                FAR const struct symtab_s *exports, int nexports)
+{
+  FAR struct nxflat_import_s *imports;
+  FAR struct nxflat_hdr_s    *hdr;
+  FAR const struct symtab_s *symbol;
+
+  char   *symname;
+  uint32  offset;
+  uint16  nimports;
+  int     i;
+
+  /* Get the ISpace load address of the module.  The NXFLAT header is the
+   * first thing at the beginning of the ISpace.
+   */
+
+  hdr = (FAR struct nxflat_hdr_s*)loadinfo->ispace;
+
+  /* From this, we can get the offset to the list of symbols imported by
+   * this module and the number of symbols imported by this module.
+   */
+
+  offset   = ntohl(hdr->h_importsymbols);
+  nimports = ntohs(hdr->h_importcount);
+
+  /* Verify that this module requires imported symbols */
+
+  if (offset != 0 && nimports > 0)
+    {
+      /* It does.. make sure that exported symbols are provided */
+
+      DEBUGASSERT(symtab && nexports > 0);
+
+      /* If non-zero, the value of the imported symbol list that we get
+       * from the header is a file offset.  We will have to convert this
+       * to an offset into the DSpace segment to get the pointer to the
+       * beginning of the imported symbol list.
+       */
+
+      DEBUGASSERT(offset >= loadinfo->isize &&
+                  offset < loadinfo->isize + loadinfo->dsize);
+
+      imports = (struct nxflat_import_s*)
+	(offset - loadinfo->isize + loadinfo->dspace);
+
+      /* Now, search the list of imported symbols and attempt to bind
+       * each symbol to the value exported by from the exported symbol
+       * table.
+       */
+
+      for (i = 0; i < nimports; i++)
+	{
+	  /* 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);
+
+	  /* 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);
+              return -ENOENT;
+	    }
+
+	  /* And put this into the module's import structure. */
+
+	  imports[i].i_funcaddress =  (uint32)symbol->sym_value;
+
+	  bvdbg("Bound imported function '%s' to address %08x\n",
+	        symname, imports[i].function_address);
+	}
+    }
+
+  return OK;
+}
+
diff --git a/nuttx/binfmt/nxflat.c b/nuttx/binfmt/nxflat.c
index e9c2b9961..53f689a9b 100644
--- a/nuttx/binfmt/nxflat.c
+++ b/nuttx/binfmt/nxflat.c
@@ -173,6 +173,16 @@ static int nxflat_loadbinary(struct binary_s *binp)
       return ret;
     }
 
+  /* Bind the program to the exported symbol table */
+
+  ret = nxflat_bind(&loadinfo, binp->exports, binp->nexports);
+  if (ret != 0)
+    {
+      bdbg("Failed to bind symbols program binary: %d\n", ret);
+      nxflat_uninit(&loadinfo);
+      return ret;
+    }
+
   /* Return the load information */
 
   binp->entrypt   = (main_t)(loadinfo.ispace + loadinfo.entryoffs);