1 files changed, 96 insertions, 0 deletions
diff --git a/cpukit/libdl/rtl-debugger.c b/cpukit/libdl/rtl-debugger.c
new file mode 100644
index 0000000000..2eff2bd055
--- /dev/null
+++ b/cpukit/libdl/rtl-debugger.c
@@ -0,0 +1,96 @@
+/*
+ *  COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtl
+ *
+ * @brief RTEMS Module Loading Debugger Interface.
+ *
+ * Inspection of run-time linkers in NetBSD and Android show a common type of
+ * structure that is used to interface to GDB. The NetBSD definition of this
+ * interface is being used and is defined in <link.h>. It defines a protocol
+ * that is used by GDB to inspect the state of dynamic libraries. I have not
+ * checked GDB code at when writing this comment but I suspect GDB sets a break
+ * point on the r_brk field of _rtld_debug and it has code that detects this
+ * break point being hit. When this happens it reads the state and performs the
+ * operation based on the r_state field.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <link.h>
+#include <rtems/rtl/rtl.h>
+#include "rtl-trace.h"
+#include "rtl-obj-fwd.h"
+
+struct r_debug  _rtld_debug;
+
+void
+_rtld_debug_state (void)
+{
+  /*
+   * Empty. GDB only needs to hit this location.
+   */
+}
+
+int
+_rtld_linkmap_add (rtems_rtl_obj_t* obj)
+{
+  struct link_map* l = (struct link_map*)obj->detail;
+  struct link_map* prev;
+  uint32_t obj_num = obj->obj_num;
+  int i;
+
+  if (rtems_rtl_trace (RTEMS_RTL_TRACE_DETAIL))
+    printf ("rtl: linkmap_add\n");
+
+  for (i = 0; i < obj_num; ++i)
+  {
+    l[i].sec_addr[rap_text] = obj->text_base;
+    l[i].sec_addr[rap_const] = obj->const_base;
+    l[i].sec_addr[rap_data] = obj->data_base;
+    l[i].sec_addr[rap_bss] = obj->bss_base;
+  }
+
+  if (_rtld_debug.r_map == NULL)
+  {
+    _rtld_debug.r_map = l;
+    return true;
+  }
+
+  for (prev = _rtld_debug.r_map; prev->l_next != NULL; prev = prev->l_next);
+
+  l->l_prev = prev;
+  prev->l_next = l;
+
+  return true;
+}
+
+void
+_rtld_linkmap_delete (rtems_rtl_obj_t* obj)
+{
+  struct link_map* l = (struct link_map*)obj->detail;
+  /* link_maps are allocated together if not 1 */
+  struct link_map* e = l + obj->obj_num - 1;
+
+  while (e && e->l_next) e = e->l_next;
+
+  if (l->l_prev == NULL)
+  {
+    if ((_rtld_debug.r_map = e->l_next) != NULL)
+      e->l_next->l_prev = NULL;
+    return;
+  }
+  if ((l->l_prev->l_next = e->l_next) != NULL)
+    e->l_next->l_prev = l->l_prev;
+  return;
+}