diff -Naurp gcc/config/avr/avr.c gcc/config/avr/avr.c
--- gcc/config/avr/avr.c	2011-02-11 14:56:08.000000000 -0600
+++ gcc/config/avr/avr.c	2011-02-11 14:54:05.000000000 -0600
@@ -211,6 +211,8 @@ static const struct attribute_spec avr_a
 #undef TARGET_EXPAND_BUILTIN
 #define TARGET_EXPAND_BUILTIN avr_expand_builtin
 
+#undef TARGET_HELP
+#define TARGET_HELP avr_target_help
 
  /* Implement TARGET_SCALAR_MODE_SUPPORTED_P.  */
  static bool
@@ -232,7 +234,24 @@ static const struct attribute_spec avr_a
    return default_fixed_point_supported_p ();
  }
  
- 
+/* Implement TARGET_HELP.  */
+void
+avr_target_help (void)
+{
+   if (avr_list_supported_parts)
+      {
+        const struct mcu_type_s *list_part;
+        fprintf (stdout, "List of parts supported by avr-gcc:\n");
+        for (list_part = &avr_mcu_types[0]; (list_part + 1)->name; list_part++)
+          {
+            if (!list_part->macro)
+               list_part++;
+            fprintf (stdout, "%-20s%s\n", list_part->name, list_part->macro);
+          }
+         fprintf (stdout, "\n");
+      }
+}
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 void
diff -Naurp gcc/config/avr/avr.opt gcc/config/avr/avr.opt
--- gcc/config/avr/avr.opt	2009-10-08 13:28:48.000000000 -0500
+++ gcc/config/avr/avr.opt	2011-02-11 14:53:20.000000000 -0600
@@ -58,3 +58,7 @@ Relax branches
 mpmem-wrap-around
 Target Report
 Make the linker relaxation machine assume that a program counter wrap-around occures.
+
+mlist-devices
+Target RejectNegative Var(avr_list_supported_parts)
+Print the list of parts supported while printing --target-help