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

1 files changed, 259 insertions, 0 deletions

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 */
+