Re: gdbserver for m68k-uclinux

[Jean-Rene Peulve <jr.peulve@wanadoo.fr>]

Hi Nathan,
Oups: I resend this because the previous email was html and got bounced by 
gdb@sources.redhat.com

I have been forced to change your patch to make it works.

1)  missing return in server.c

2) I also add an fprintf to stderr with the address of the text and data 
section to allow the use of add-symbol_file command which requires these 
address.
   The response to qOffsets being hidden by gdb, I then can get it from the 
target console or telnet.

Jean-René Peulvé

Here are my revised patches based on yours:

--- server.c.orig       2006-02-08 20:26:00.000000000 +0100
+++ server.c    2006-05-09 11:07:15.000000000 +0200
@@ -129,6 +129,23 @@
         }
      }

+   if (the_target->read_offsets != NULL
+       && strcmp ("qOffsets", own_buf) == 0)
+     {
+       CORE_ADDR text, data;
+
+       if (the_target->read_offsets (&text, &data)) {
+         sprintf (own_buf, "Text=%lX;Data=%lX;Bss=%lX",
+                (long)text, (long)data, (long)data);
+         return;
+       }
+       else
+         write_enn (own_buf);
+
+       return;
+    }
+
+
    if (the_target->read_auxv != NULL
        && strncmp ("qPart:auxv:read::", own_buf, 17) == 0)
      {
--- linux-low.c.orig    2006-05-09 11:21:12.000000000 +0200
+++ linux-low.c 2006-05-09 10:58:55.000000000 +0200
@@ -140,7 +140,11 @@
    void *new_process;
    int pid;

+#if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__)
+  pid = vfork ();
+#else
    pid = fork ();
+#endif
    if (pid < 0)
      perror_with_name ("fork");

@@ -896,7 +900,7 @@
    if (debug_threads && the_low_target.get_pc != NULL)
      {
        fprintf (stderr, "  ");
-      (long) (*the_low_target.get_pc) ();
+      (*the_low_target.get_pc) ();
      }

    /* If we have pending signals, consume one unless we are trying to reinsert
@@ -1550,6 +1554,52 @@
      return 0;
  }

+#if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__)
+#if defined(__mcoldfire__)
+/* These should really be defined in the kernel's ptrace.h header.  */
+#define PT_TEXT_ADDR 49*4
+#define PT_DATA_ADDR 50*4
+#define PT_TEXT_END_ADDR  51*4
+#endif
+
+/* Under uClinux, programs are loaded at non-zero offsets, which we need
+   to tell gdb about.  */
+
+static int
+linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
+{
+#if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && 
defined(PT_TEXT_END_ADDR)
+  unsigned long text, text_end, data;
+  int pid = get_thread_process (current_inferior)->head.id;
+
+  errno = 0;
+
+  text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0);
+  text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0);
+  data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0);
+
+  fprintf(stderr, "text=%lx data=%lx errno=%d\n", text, data, errno);
+  if (errno == 0)
+    {
+      /* Both text and data offsets produced at compile-time (and so
+         used by gdb) are relative to the beginning of the program,
+         with the data segment immediately following the text segment.
+         However, the actual runtime layout in memory may put the data
+         somewhere else, so when we send gdb a data base-address, we
+         use the real data base address and subtract the compile-time
+         data base-address from it (which is just the length of the
+         text segment).  BSS immediately follows data in both
+         cases.  */
+      *text_p = text;
+      *data_p = data - (text_end - text);
+
+      return 1;
+    }
+#endif
+ return 0;
+}
+#endif
+
  static struct target_ops linux_target_ops = {
    linux_create_inferior,
    linux_attach,
@@ -1569,6 +1619,9 @@
    linux_remove_watchpoint,
    linux_stopped_by_watchpoint,
    linux_stopped_data_address,
+#if defined(__UCLIBC__) && !defined(__UCLIBC_HAS_MMU__)
+  linux_read_offsets,
+#endif
  };

  static void